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+--------------------------------------------------------------------+ | | | A S I C 3.00 | | | | "Its Almost Basic" | | | | | | Copyright 1991 | | by | | David A. Visti | | | | All Rights Reserved | +--------------------------------------------------------------------+ | ASIC 3.00 is provided as shareware. Under the shareware concept, | | you can test a program before you buy it. If you find it suitable | | for your needs and make use of this program, you are expected to | | send a $10 registration fee. | | | | Feel free to distribute this software to others. However, you | | may not charge for the distribution of this software to others | | nor may you alter the software or this documentation. | | | | Registered users of any version of ASIC will receive a diskette | | containing the current version of ASIC, plus may purchase future | | updates at half of the normal registration price. A printed | | manual is available to registered users for an additional $10.00. | | | | For further ordering information, please see the file ORDER.FRM, | | included with ASIC. | +--------------------------------------------------------------------+ | | | Please send registration fees and suggestions to: | | | | David Visti | | P.O. Box 2952 | | Raleigh, NC 27602-2952 | | | | Please mention the version of ASIC in any correspondence | | (This is ASIC Version 3.00) | +--------------------------------------------------------------------+ | I can also be reached for questions/comments on GEnie and | | Compuserve via EMAIL: | | | | Compuserve 73065,1302 | | GEnie D.VISTI | | | +--------------------------------------------------------------------+ | | | DISCLAIMER: This software is provided "as is" without warranty | | of any kind. In no event shall I be held liable for any damages | | whatsoever arising from the use of or inability to use this | | product. | | | | Your registration fee entitles you to use this software on a | | single computer. Site licenses are available, write for details. | +--------------------------------------------------------------------+ A S I C Table of Contents Chapter Title 1. Getting Started Page 3 2. Tutorial Page 5 3. Integrated Editor/Compiler Environment Page 11 4 Using the Debugger Page 22 5. Stand-alone Compiler Options Page 30 6. Language Elements Page 33 7. Keyword Reference Page 39 ABS Page 39 ASC Page 39 BEEP Page 40 BLOAD Page 41 BSAVE Page 42 CALL Page 43 CHDIR Page 44 CHR$ Page 45 CLOSE Page 45 CLS Page 46 CODE Page 46 COLOR Page 47 COMMAND$ Page 48 COMSTAT Page 49 CSRLIN Page 50 DATA Page 51 DATE$ Page 52 DEFSEG Page 52 DIM Page 53 END Page 53 ENVIRON$ Page 54 FILEPOS Page 55 FIND Page 57 FOR/NEXT Page 59 GETDIR Page 60 GOSUB Page 61 GOTO Page 61 IF/THEN/ELSE/ENDIF Page 62 INKEY$ Page 64 INP Page 64 INPUT Page 65 INPUT# Page 66 INSTR Page 68 INT86 Page 69 KILL Page 71 LCASE$ Page 71 LEFT$ Page 72 LEN Page 72 LOCATE Page 73 LPRINT Page 73 LTRIM$ Page 74 MID$ Page 74 MKDIR Page 75 Page - 1 Table of Contents (Continued) Chapter Title 7. Keyword Reference (Continued) MOD Page 75 NAME Page 76 OPEN Page 76 OPENCOM Page 77 OUT Page 78 PEEK Page 78 POINT Page 79 POKE Page 80 POS Page 80 PRESET Page 81 PRINT Page 81 PRINT# Page 82 PSET Page 84 RANDOMIZE Page 84 READ Page 85 RECEIVE Page 86 REM Page 87 RESTORE Page 87 RETURN Page 88 RIGHT$ Page 88 RMDIR Page 89 RND Page 90 RTRIM$ Page 91 RUN Page 92 SCREEN Page 93 SEND Page 94 SOUND Page 94 SPACE$ Page 95 STR$ Page 95 STRING$ Page 96 TIME$ Page 97 TIMER Page 98 UCASE$ Page 99 VAL Page 99 VARPTR Page 100 WHILE/WEND Page 100 WIDTH Page 101 ZBIT Page 101 ZMODE Page 102 8. Compatibility with BASICA/GWBASIC Page 103 9. Technical Details/Tips Page 106 10. Error Messages Page 111 Page - 2 A S I C Chapter 1 Getting Started INTRODUCTION Welcome to ASIC! ASIC is a "BASIC" programming language compiler for IBM PCs and compatibles. It includes an integrated full screen editor, from which you can edit, compile, and debug your programs. Or at your option, you can use your own text editor, and compile your programs from the MS DOS command line. ASIC is a subset of BASICA and GWBASIC which supports over 80 BASIC statements, integer and string variables, and integer arrays. It will compile your programs at high speed, and the code it generates is fast and compact. The syntax of each ASIC statement is generally a valid subset of the syntax used by BASICA and GWBASIC (exceptions are noted in Chapter 8.) All you need to get started is: 1) ASIC 2) IBM PC or 100% Compatible 3) 305-405k Available Memory* 4) Two floppy disk drives <or> One hard disk drive and one floppy disk drive The first step is to install ASIC as described below. Then, proceed to Chapter 2 for a brief ASIC tutorial. Following that you can read the remainder of the documentation straight through, or refer to it as you need it. Have Fun! * The ASIC Compiler will run in 305k of memory. The ASIC Editor will run in less than 200k of memory, however, to compile and debug within the editor, 405k of available memory is required. If ASIC does not find sufficient memory to call the compiler from within the editor, it will ignore the compile request and return to the editor. Page - 3 INSTALLATION To install ASIC execute the following commands as appropriate for your machine. The procedure to do so is provided below for both floppy systems and hard disk based systems. Also refer to the README file on your ASIC Diskette for additional information. TWO-FLOPPY DISK SYSTEM INSTALLATION 1) Make sure that the following files are all on the same diskette (the diskette that contains these files will be referred to in this manual as the "Compiler" diskette): ASIC.EXE ASICC.EXE ASIC.IDX (Optional) ASICM.IDX (Optional) ASIC.DOC (Optional) (Note: The optional files are required if you wish to use the extended online help feature). 2) Format one or more blank diskettes to hold your programs (these diskettes will be referred to in this manual as your "Program" diskettes): Note: Whenever you see the symbol <enter> in this document, this refers to the <enter> or <return> key on your keyboard. HARD DISK SYSTEM INSTALLATION 1) Type: C: <enter> 2) Type: MD C:\ASIC <enter> 3) The next step is to copy the ASIC software to the ASIC directory. If your ASIC software is on a floppy, insert the floppy in Drive A: then type the command: COPY A:*.* C:\ASIC <enter> If your ASIC software is already on a hard disk directory, copy it to the ASIC directory with the command: COPY C:\directoryname\*.* C:\ASIC <enter> Note that ASIC will run from any subdirectory, however, the tutorial assumes ASIC is under C:\ASIC Note: Whenever you see the symbol <enter> in this document, this refers to the <enter> or <return> key on your keyboard. Page - 4 A S I C Chapter 2 Tutorial ASIC programs look very much like regular "BASIC" programs which you are probably already familiar with. The one very noticeable difference is that ASIC programs have no line numbers. Let's take a look at a very simple program written both in GWBASIC/BASICA and in ASIC: GWBASIC/BASICA ASIC --------------------------+---------------------------------- | 10 I=I+1 | ADDONE: I=I+1 20 PRINT I | PRINT I 30 IF I<100 THEN 10 | IF I<100 THEN ADDONE: --------------------------+---------------------------------- Both of these programs do the same thing. They display the numbers from 1 to 100. However, notice that ASIC allows you to use descriptive labels (ADDONE) instead of a line number (10). These labels can be up to 80 characters long! Also note that the ASIC "PRINT" and "IF" statements were indented only for increased program readability. The ASIC program could just as well have been written as: ASIC ------------------------------ ADDONE:I=I+1 PRINT I IF I<100 THEN ADDONE: ------------------------------ We could have made our variable names longer. Instead of "I" we could have chosen "SECONDS" or "VELOCITY", or some other name up to 80 characters in total. In ASIC, variable names, labels, and string constants can all be up to 80 characters in length. Well, now that we've seen a basic ASIC program, let's try to enter and run a slightly larger program. The program we will be working with will print the message "HELLO yourname" in 256 color combinations. If you have a monochrome display card, don't worry, the program will work, but instead of seeing different colors you'll see characters with different attributes, such as blinking, underlined, etc. Let's get started. If you haven't done so already, install ASIC as described in Chapter 1. Now then, writing an ASIC program involves these three steps. 1. Write your program. 2. Compile your program. 3. Run/Test your Program. Page - 5 These three steps can all be performed from within the ASIC Integrated Environment. Before we proceed with our "Hello yourname" Program, let's go over some conventions. In the following section: FLOPPY TYPE--> Means that only 2-floppy disk system users should type this line. HARD TYPE--> Means that only hard disk system users should type this line. TYPE--> Means that both floppy and hard disk users should type this line. X> This is a representation of the prompt from PC-DOS or MS-DOS. Floppy Disk Users will actually see "A>" for a prompt. Hard Disk Users will see "C>" for a prompt. <enter> Means that you should press the <enter> or <return> key on your keyboard. <?> Text enclosed between the "<" and the ">" symbols indicate a key to type. Don't type the "<" or ">" symbols. For example, if the tutorial lists "<F1>", your should press the "F1" key on your keyboard. NOTE: Floppy Disk users need to insert their ASIC Compiler diskette in Drive A: at this point, and a Program diskette in Drive B: (See the Installation section for more information) Let's begin: FLOPPY TYPE--> A: <enter> HARD TYPE--> CD C:\ASIC <enter> The computer should respond: X> Now enter the command to invoke ASIC: TYPE--> ASIC <enter> You are now in ASIC. The top line is the Menu Bar. The bottom line is the Status Line. Chapter 3 describes this in more detail. For now, we'll just describe a couple of features on these lines. The status line indicates that the current mode is "INSERT". This means that any characters you type on a line will be inserted between the existing characters. If you press the <INS> key on the keypad, ASIC will toggle to its other mode, OVERSTRIKE. In this mode, when you type Page - 6 a character, it overlays the character that was there before. Each time you press the <INS> key, ASIC will toggle between the INSERT and OVERSTRIKE modes. You can open the menus listed on the "Menu Bar" by holding down the ALT key while typing the Capitalized letter of the menu you wish to open. For example, to open the File menu, press <ALT><F>. Try it now: TYPE--> <Alt><F> The "File" menu will pop open. You can select a menu option from that menu by typing the capitalized letter of the option, or by using the arrow keys on your keypad to highlight the option you want and then pressing <enter>. If you are not sure what the menu option will do, you can press <F1> and ASIC will display some help information for the highlighted menu option. When you opened the File menu, the first option on that menu, "Open" was highlighted. Let's get some help on "Open": TYPE--> <F1> ASIC will display some help information on "Open". Let's close the help window now: TYPE--> <ESC> The help window will close. The <ESC> key will always let you escape from any menu or help screen in ASIC, without taking any action. Let's also close the file menu for now: TYPE--> <ESC> The "File" menu should have closed. By the way, in addition to the menu help, ASIC provides additional online help. If you need general ASIC help, press the <F1> key for a quick summary of some of ASIC's features: TYPE--> <F1> ASIC will display some general help. From this screen, we can also retrieve additional information about BASIC statements such as PRINT or GOSUB. Let's bring up an index of these statements. TYPE--> <F1> ASIC has opened a help index screen. From this screen we can use the arrow keys to highlight any ASIC keyword and obtain more information for that keyword by then pressing enter. We won't do that now, but don't forget that this screen is available. Chapter 3 of the ASIC Reference Manual describes all of the online "HELP" features available in ASIC and provides a full description of the ASIC Editor Commands which are available. Exit the help menu: TYPE--> <ESC> Page - 7 Entering a program in ASIC is simplicity itself. We'll simply type in each line, pressing <enter> at the end of each line. If you make a typing mistake, just use the arrow keys to move to the error, and type in the correction. Use the <DEL> or <Backspace> keys to delete any unwanted characters from the screen. Make sure the status line says "Mode: Insert". This is the default mode in ASIC. If it doesn't, press the <INS> key until it does. Now let's enter our program (the program below intentionally contains an invalid ASIC statement. We'll correct the line later in the tutorial, for now, type in the program exactly as it's listed below): TYPE--> CLS <enter> TYPE--> PRINT "Please enter your name"; <enter> TYPE--> INPUT YOURNAME$ <enter> TYPE--> FOR I=1 TO 16 <enter> TYPE--> FOR J=1 TO 16 <enter> TYPE--> COLOR I,J <enter> TYPE--> PRINT "HELLO "; <enter> TYPE--> PRINT YOURNAME$; <enter> TYPE--> NEXT J <enter> TYPE--> NEXT I <enter> TYPE--> CLS <enter> TYPE--> THE END <enter> There, that was easy. Now, let's compile our program. To do it, we'll open the "Compile" menu, and select the "Compile program" option: TYPE--> <ALT><C> The "Compile" menu will pop open. The first option, "Compile program" can be selected by typing the option letter which is capitalized "C", or by moving the highlight bar to this option and pressing the <enter> key. Since the highlight bar is already on this option, let's just press <enter>: TYPE--> <enter> Since we didn't specify a file name when we invoked ASIC, ASIC will now ask for a file name (so it can save your program before calling the compiler): FLOPPY TYPE--> B:TUTOR.ASI <enter> HARD TYPE--> TUTOR.ASI <enter> Note that ASIC requires that your programs be stored in files ending with the extension ".ASI". Had we entered "TUTOR" for our program name, ASIC would have appended the letters ".ASI" for us. If we tried to provide a different extension, such as "TUTOR.SRC", ASIC would display an error message. Also, whenever you are presented a dialog box where you are asked to enter text (such as file name, or Yes/No responses to questions), you must press the <enter> key before ASIC will accept the input. Once you select the "Compile program" option, you'll see the ASIC compiler screen appear. It will display a count of the lines compiled, and when it is done, it will return to the ASIC editor. Page - 8 If it detected any errors, it will display the first error message at the bottom of the editor screen. It will also highlight the line in your program which is in error. In this case the line "THE END" was flagged with the error message "Syntax Error". Of course, that line should have been entered simply as "END". That should be easy enough to fix. Let's exit the error menu by pressing the <ESC> key: TYPE--> <ESC> The error menu has disappeared, and our cursor is now on the erroneous line. To fix the line: TYPE--> <DEL><DEL><DEL><DEL> That should do it. The last line of our program should now read "END". Before we continue, let's assume we new the name of the END command, but could not remember the proper syntax for it. ASIC provides an online lookup for each ASIC statement. With the cursor positioned somewhere on the word "END": TYPE--> <Ctl><F1> ASIC should have opened a help window describing the "END" statement. To return to your program press the <ESC> key. TYPE--> <ESC> The help window should have disappeared and you should see your program displayed again. Let's recompile the program: TYPE--> <ALT><C> TYPE--> <enter> This time you should see the message "No Compiler Errors". If you didn't, check your spelling and recompile the program until you receive this message. Press <ESC> to remove the "No Compiler Errors" Window. Now let's run the program. To do so, we'll open the "Run" menu, and select the "Run your program" option. TYPE--> <ALT><R> TYPE--> <r> This time, we just entered the capitalized letter from the menu option "Run your program". Your computer screen should now prompt you to "Please enter your name?". Go ahead and enter your name now: TYPE--> yourname <enter> You should see "HELLO yourname" printed in various color combinations, and then the ASIC editor screen will reappear. Well, that's all there is to writing, compiling, and running an ASIC program. Now, to exit ASIC, open the "File" menu and select the "eXit" option. Page - 9 TYPE--> <ALT><F> TYPE--> <X> You should see your MS DOS prompt once again. By the way, now that you've successfully compiled the program, you can execute it directly from MS DOS. Let's try it: HARD TYPE--> TUTOR <enter> FLOPPY TYPE--> B:TUTOR <enter> Well, that's a brief introduction to ASIC! Next, you might want to read Chapter 3, "Integrated Editor/Compiler Environment" to learn about the many other features available in the ASIC editor. Following this you should read Chapter 4 which explains how to use the ASIC Debugger. Chapter 4 includes another short tutorial in which you debug a program. The remaining chapters provide reference material which you can either read, or just refer to as needed. Chapter 5 explains how to compile programs directly from the command line of DOS. Chapters 6-8 describe the BASIC statements which are supported by ASIC. Chapter 10 provides more descriptive information for ASIC error messages. Hope you enjoy programming in ASIC! Page - 10 A S I C Chapter 3 Integrated Editor/Compiler Environment INTRODUCTION The ASIC integrated environment lets you edit, save, compile, and debug your ASIC programs without ever leaving ASIC! This chapter will explain the usage of the integrated environment. ASIC SCREEN CONTENTS ASIC divides the screen into three parts. The top line is called the "Menu Bar". All of the menus available to you are listed on this line. The bottom line is called the "Status Line". It continuously displays some important program information. The middle 23 lines are the "Edit Window". This is the section of the screen where you can make changes or additions to your program. MENU BAR PROCESSING Currently, there are four menus available. The "File" menu allows you to load/save your existing program files to/from disk. It is also used to exit ASIC. The "Edit" menu contains various editing commands which are available. The "Compile" menu is used to compile your program, set compiler options, and to view compiler errors. The "Run" menu allows you to run your programs, and test them using the ASIC debugger. To open a menu, hold down the <ALT> key and type the first letter of the menu. The menu will pop down and display the options available on that menu. If you want to close the menu without taking any action, press the <ESC> key. If you wish to open a different menu without first closing the current menu, press the left or right arrow keys. Otherwise, to select an option, type the capitalized letter of the menu option. For example, on the "File" menu, to select the "eXit" option, type an "X" or an "x". Another way to select an option is to move the "Highlighted Bar" down to the option you wish to select, and press the <enter> key. Some functions may be accessed outside of the menus with function keys. These are listed on the menus (eg. "search Again <F3>" on the Edit Menu), however, these function keys do not operate when a menu is open. (A list of these Function keys is presented later in this chapter in the Keyboard Usage Section). Page - 11 GETTING HELP ASIC provides "online" help within the integregated environment to assist you with keyboard usage, menu options, and ASIC keywords. This section tells you how to access this online help. General Help General describes the usage of the keyboard in ASIC. Keyboard keys which perform ASIC functions are described in this section. Access general help by pressing Function key <F1>. Pressing <F1> a second time will display an ASIC keyword index. You can get additional help on individual ASIC keywords from this screen. This information includes a description of what the keyword does, and the keyword syntax. Menu Help If you open a menu, but you are not sure what a certain menu option does, you may display a description of the highlighted menu option by pressing the <F1> key. Doing so will open a help window which describes the menu option. Press <ESC> to exit the help screen and return to the menu. Keyword Help Can't remember the syntax for a particular ASIC keyword? Well, help is just a keystroke away. Position the cursor on the keyword in the edit buffer. Then, hold down the <Ctl> key and press the <F1> key. ASIC will display a description of the keyword, and describe proper syntax for that keyword. For example, if you tried to compile a program, but received a syntax error on the keyword "PRINT" in your program, you could obtain help on the "PRINT" statement by using the arrow keys to position the cursor anywhere on the word "PRINT" and then pressing <Ctl-F1>. If ASIC cannot find the keyword (eg, say the cursor was positioned on a variable called "APPLES", which is not an ASIC keyword), then ASIC will display a list of valid keywords. Use the cursor keys to highlight one of these keywords and press <enter> to retrieve help for the highlighted keyword. You may also access this keyword help list by pressing the <F1> key twice from within the editor. Now let's describe the options available on each menu. FILE MENU "Open" Option This option allows you to open an existing ASIC file and load it into the ASIC edit buffer where you can modify it. If you select this option another window will open to ask you the file name. If you don't wish to open a file, you can press <ESC> to close the menu without taking any action. Otherwise, enter an ASIC file name, and press the <enter> key. Page - 12 FILE MENU (Continued) "Save" Option This option allows you to write the changes you've made to your program back to the file. Changes you enter in the ASIC editor are made to memory only. You must select this option before your changes will become permanent. Note: Your file is saved to disk automatically whenever you compile it or run it, if the file modified indicator is set. "save As" Option This option will allow you to write the changes you've made to the program in the edit buffer to a new file. You will be prompted to provide ASIC with a new file name. "eXit" Option This option will allow you to exit from ASIC back to MS DOS. ASIC will ask you if you wish to save your file before you exit. EDIT MENU "Begin block" Option This option will allow you to mark the beginning of a block of text for use with the block delete, copy, and move commands. To mark a block of text, move the cursor to the first line of the block, and then select this option. The beginning line of the block will be highlighted on the screen. Next, move the cursor to the ending line of the block, and select the "End block" option from this menu. All of the lines in the block will be highlighted. This block of lines can now be "moved", "copied", or "deleted" using the block commands. "End block" Option This option will allow you to mark the end of a block of text. Refer to the "Begin block" Option for more information. "Search" Option This option allows you to locate a string of characters in the edit buffer. When you select this option, ASIC will ask you for a search string which can be up to 30 characters in length. ASIC will then search forward from the current line until it finds the string or reaches the end of the edit buffer. If it finds the string, the cursor will be placed on the line containing the string. Page - 13 EDIT MENU (Continued) "Replace" Option This option will allow you to replace one or more occurrences of a string of characters with another set of characters. When you select this option, ASIC will ask you for a search string which can be up to 30 characters in length. ASIC will then ask you for the string of characters which is to replace the search string. Finally, ASIC will ask you to specify how many occurrences of this search string are to be replaced (from 1-9999). ASIC will search forward from the current line, and briefly display each line as it modifies it. If it reaches the end of the edit buffer before it has replaced the number of occurrences you've specified, ASIC will display an "End of Buffer" message, and stop. "Delete block" Option This option will delete a block of lines. Refer to the "Begin block" option for information on marking a block of lines. If you haven't marked a block of lines, selecting this option will have no effect. "Move block" Option This option will move a block of lines to a new location in the edit buffer. Refer to the "Begin block" option for information on marking a block of lines. If you don't mark a block of lines, selecting this option will have no effect. Once you have marked a block of lines, move the cursor to the location in the edit buffer where you want the lines moved. Selecting the "Move block" option will result in the block of lines being deleted from their current location, and moved to the buffer at the line following the cursor. ASIC will not overlay lines, it will insert enough blank space to hold the relocated text. "Copy block" Option This option is the same as the "Move block" option, with one exception. After moving the block, ASIC does NOT delete the original block of lines. Use this option to clone a block of text. Refer to the "Begin block" option for information on marking a block of text. "search Again <F3>" Option This option will allow you to search for the next occurence of the last string you searched for with the "Search" Option, without retyping the previous search string. This option may also be selected outside of the Edit Menu by pressing function key <F3>. Page - 14 COMPILE MENU "Compile program <F10>" Option Use this option to have ASIC compile the program which is currently loaded in the edit buffer. If the compile is successful, ASIC will display the message "No Compiler Errors". Otherwise, it will display the first error message (see "View compile errors" option). ASIC will automatically save your program before calling the compiler. This option may also be selected outside of the menu by pressing function key <F10>. "Full program listing" Option This menu option, and the next four options are used to toggle various compiler options on or off. When the option is on, you will see a "check mark" symbol next to the option. This compiler option will cause ASIC to display each source line as it compiles it. This option will slow down the compile, but since ASIC also writes these lines to a listing file, this option can be used to create a compile listing. The compile listing will be contained in a file called "progname.LST", where "progname" is the name of your program. "Printer output" Option This menu option will toggle the "Printer output" compiler option on or off. When the option is on, you will see a "check mark" symbol next to the option name. This compiler option will cause compiler messages to be printed on your printer. "Symbol table" Option This menu option will toggle the "Symbol table" compiler option on or off. When the option is on, you will see a "check mark" symbol next to the option name. This compiler option will cause ASIC to create a symbol table file called "progname.SYM", where "progname" is the name of your program. The symbol table is a list of all variables, labels, and internally created compiler addresses. "Extended math" Option By default, ASIC will permit regular integer variables. These variables are very efficient and only require two bytes (or characters) of memory storage. However, these integers can only hold numbers in the range of -32767 to +32767. For many programs this is sufficient. However, there may be cases when you want to represent larger integer values. Because of this, ASIC provides a "long" integer data type. The long integer requires four bytes of memory storage. However, it can hold a much larger range of numbers. A long integer can store numbers in the range of -2,147,483,647 to +2,147,483,647. When you need to use long integers in your program, you need to turn on this option, so that ASIC can generate the proper code. If this option is not turned on and your program contains long integers, ASIC will generate a compiler error. If this happens, just turn this option on, and re-compile your program. To "create" a long integer variable or constant, simply append the "&" character to the variable name or constant value(eg, SAMPLEVAR& or 123456&). For further information on using long integers, refer to Chapter 6, "Language Elements", of the ASIC Manual. Page - 15 COMPILE MENU (Continued) "Debugging code" Option This menu option will toggle the "Debugging code" compiler option on or off. When the option is on, you will see a "check mark" symbol next to the option name. This compiler option will cause ASIC to generate code required by the ASIC debugger to allow you to set breakpoints, single step through your program, and view/modify program variables. This option is "on" by default in the integrated environment. You should leave this option on while you are debugging your program. When you have everything working properly, you should turn it "off" and recompile your program. This will reduce the size of your program slightly, and will make it run faster (of course, you can't use the debugger with it, since there is no debugging information available to ASIC any more. If you need to debug your program again, just recompile with the this option turned "on" again). "View compile errors" Option When you wish to examine the errors from a previous compile of your program, select this option. If no errors exist, ASIC will so inform you. Otherwise, ASIC will display the first error message at the bottom of the screen, and it will highlight the line of your program which corresponds to that error. If you wish to correct the program line, press the <ESC> key. The cursor will be positioned at the beginning of that program line. You may also view subsequent compiler errors by pressing the <F10> key instead of the <ESC> key. "Write options to disk" Option Normally, when you set compiler options in the integrated environment, they "exist" only for your editing session (ie, when you leave the editor, ASIC resets the options to the defaults). If you prefer, you may use this option to cause ASIC to write the current session's options to a configuration file (ASIC.CFG). Then, when you invoke the ASIC integrated environment, it will first check for this configuration file. If found, it will use your saved configuration. Otherwise, it will use the ASIC defaults. This configuration file is not accessed by the command-line version of the compiler, so they only take affect when you are inside the integrated environment. Page - 16 RUN MENU The "Using the ASIC Debugger" Chapter has additional information on the debugger and it's options. You may wish to refer to it, should you need more information than is provided below. "Run your program <F5>" Option After you have successfully compiled your program, you can select this option to cause ASIC to load and execute your program. After your program ENDs, ASIC will return you to the editor. ASIC will save the edit buffer before loading and executing your program. If you are running a program containing debugging code, this option will cause ASIC to run your program up to the first breakpoint it encounters, or through the end of your program if you haven't set any breakpoints. If you are already "paused" at a breakpoint, selecting this option will cause your program to resume execution at the statement following the breakpoint, and run up to the next breakpoint or to the end of your program, if no further breakpoints are encountered. This option may also be selected outside of the "Run menu" by pressing function key <F5>. "Breakpoint toggle <F9>" Option If you have compiled your program with the "Debugging code" option turned on, you may use this option to set breakpoints. You can have up to 20 breakpoints active at a time. When you run your program with breakpoints set, ASIC will pause your program when it tries to execute a line on which you have set a breakpoint. At this time, you can view or modify variables, or view the screen output produced by your program. You can then resume program execution by selecting the "Run your program" option from the run menu. If you select this option and the current statement in the edit buffer already has a breakpoint set, then the breakpoint for that source statement will be removed (toggled off). Lines at which you have set a breakpoint will be displayed in reverse video. Also, when you run your program and ASIC stops at a breakpoint, ASIC will display the next line to execute in reverse video on the second line of the screen with a red background (underlined if you have a monochrome system). This option may also be selected outside of the "Run" Menu by pressing function key <F9>. "Trace <F8>" Option If you have compiled your program with the "Debugging code" option turned on, you may use this option to execute your program one statement at a time. After you select this option, ASIC will execute the next program statement in your program, and pause, displaying the next line which will be executed in reverse video with a red background (underlined if you have a monochrome system). At this time, you can view or modify variables, or view the screen output produced by your program. You can then resume program execution by selecting the "Run your program" option from the run menu, or by selecting the "Trace" option again. This option may also be selected outside of the "Run" Menu by pressing function key <F8>. Page - 17 RUN MENU (Continued) "Modify variable" Option If you have compiled your program with the "Debugging code" option turned on, you may use this option to modify the contents of variables in your program while your program is paused at a breakpoint or following a "Trace" command. When you select this option, ASIC will ask you for the variable name. After you enter the variable name, ASIC will ask you for the new value to be stored in the variable. If the variable is an array, ASIC will ask you which element of the array to modify. "Watch variable <F6>" Option If you have compiled your program with the "Debugging code" option turned on, you may use this option to view the contents of variables in your program, while your program is paused at a breakpoint or following a "Trace" command. After you enter the variable name, ASIC will open a "Watch" window at the bottom of the screen showing you the variable name and the current value. As you continue execution of your program and reach a new breakpoint, the values of variables will be updated to reflect their new values. In this way you can watch the changing values of variables in your program without inserting "PRINT variablename" statements in your program. Up to 10 variables may be watched at a time. If you enter a variable name which is an array, ASIC will ask you which element of the array you wish to watch. This option may also be selected outside of the "Run" Menu by pressing function key <F6>. "Unwatch variable <F7>" Option If you have compiled your program with the "Debugging code" option turned on, you may use this option to remove variables from the "Watch" window (see previous option). When you select this option, you will be asked for a variable name to remove from the window. If the variable is an array, you will also be asked which element of the array. ASIC will then remove the variable from the watch window, and resize the window accordingly. Since only 10 variables may be watched concurrently, you may need to remove variables which are no longer needed from the "Watch" Window using this command. This option may also be selected outside of the "Run" Menu by pressing function key <F7>. "Abort execution" Option If you are running your program, and it is paused at a breakpoint, you may select this option to abort the execution of your program. Your program will be terminated immediately. "Clear all break/watch" Option If you have set breakpoints or watch variable options, you may use this option to remove all of them at once, instead of removing them one at a time using the "Toggle breakpoint" or "Unwatch variable" options. Page - 18 RUN MENU (Continued) "Program arguments" Option This option allows you to pass command line arguments to your programs, which may be retrieved by your program using the COMMAND$ statement. If you are testing outside the integrated environment, you would normally specify the command line arguments by typing "progname arguments". However, in the integrated environment, since ASIC is executing your program for you, this option is a means to pass the "arguments" to your program as if they had been typed on the command line following your program name. "Swap to user screen <F4>" Option Whenever ASIC pauses your program at a breakpoint, it saves the screen created by your program in a memory buffer. You may select this option to view your program screen output. When you are done viewing your program's output, press a key to return to viewing the ASIC editor. This function may also be selected outside the "Run" Menu by pressing the <F4> function key. STATUS LINE The bottom line of the ASIC screen is called the "Status Line". As it's name implies, it is used to display various types of status information. At the left of the status line "FILE: xxxxxxxx.xxx" will display the name of the file which is currently loaded in the edit buffer. If you haven't opened a file yet, the file name will be blank. After the file name is the "File Modified Indicator". If you have entered any changes in the edit buffer, and have not saved them to disk, an "*" will appear to indicate this. If the edit buffer has not been modified since the last save to disk, no "*" will be present. The next piece of information is "Mode:". Mode will always display one of two values: "Insert" or "Ovrstr". In "Insert" mode, any characters you type in the edit buffer will be inserted at the cursor position, and the characters to the right of the cursor will be shifted to the right by one. In "Ovrstr" mode, any characters you type in the edit buffer will overlay (and thus destroy) the character at the cursor position. You can change back and forth between these two modes by pressing the <INS> key on your keypad. To the right of "Mode:" ASIC displays the number of bytes which it allocated to the edit buffer. Divide this number by 81 to get a rough idea of how many lines will fit in the edit buffer. The "Line: nnnn" status indicator, will identify which line of the file is being displayed. For example, if the display reads "Line: 100", the line containing the cursor is the 100th line in the file. When ASIC is reading or writing your program to/from disk, it will display a running total of the number of records read/written in this field. Page - 19 STATUS LINE (Continued) The "Row:" and "Col:" numbers identify the relative position of the cursor within the "Edit Window". EDIT WINDOW The edit window is the area of the screen where your program is displayed. It displays up to 23 lines of your program at a time. You can use the keys described below to manipulate the text in this window. KEYBOARD USAGE Most keys on the keyboard behave in ASIC just as you'd expect. The key usages which might not be obvious are described here. <ESC> Exit from any menu without taking any action. <TAB> Move the cursor to the next "tab stop". Tab stops in ASIC are fixed at every fourth column (4,8,12,etc). <HOME> Move the cursor to the beginning of the current line. <END> Move the cursor to the first blank character following the last non-blank character on the current line. <DEL> Delete the character at the cursor position. <INS> Toggle between Insert and Overstrike Modes. <PGUP> Display the previous "page" of the edit buffer. <PGDN> Display the next "page" of the edit buffer. <Ctl-PGUP> Display the first "page" of the edit buffer. <Ctl-PGDN> Display the last "page" in the edit buffer. <Backspace> Delete the character to the left of the cursor position, and move the cursor one column to the left. Page - 20 KEYBOARD USAGE (Continued) <Up Arrow> Moves cursor up one line. <Down Arrow> Moves cursor down one line. <Left Arrow> Moves cursor left one column. <Right Arrow> Moves cursor right one column. <Alt-D> Delete the line containing the cursor. <Alt-A> Add a line following the line containing the cursor. <F1> Displays a help screen. <CTL-F1> Displays help information for the keyword located at the cursor postion. <F3> Repeats the last "Search" command. See Edit Menu Section of this chapter for more information. <F4> Swaps the display to the output from your program temporarily. See Run Menu Section of this chapter for more information. <F5> Runs your program. See Run Menu Section of this chapter for more information. <F6> Add a variable to the "Watch" Window. See Run Menu Section of this chapter for more information. <F7> Remove a variable from the "Watch" Window. See Run Menu Section of this chapter for more information. <F8> Execute a single statement of your program. See Run Menu Section of this chapter for more information. <F9> Toggle breakpoint on/off at the current edit buffer line. See Run Menu Section of this chapter for more information. <F10> Compile your program. See Compile Menu Section of this chapter for more information. <enter> In Insert mode, pressing <enter> is identical to pressing <Alt-A>. In OvrStr mode, pressing <enter> is identical to pressing the <Down Arrow> key. Page - 21 A S I C Chapter 4 Using the Debugger INTRODUCTION The source level debugger in ASIC's integrated programming environment helps you debug your programs by allowing you to "peek" inside them as they're running. You can single step through your programs, or select places in the program where you wish execution to pause by setting breakpoints. Then, while the program is paused, you can view or modify any of your program's variables, and also examine the screen output created by your program. All of the debugger's commands can be selected from the run menu, and they are described in the "RUN MENU" Section of Chapter 3, "Integrated Editor/Compiler Environment". Many of the debugger commands may be selected outside the "Run" menu, by pressing a function key (eg, <F5>,<F6>,etc). A complete list of the function keys available is contained in Chapter 3, in the "KEYBOARD USAGE" Section. This chapter explains how to use the debugger with a short tutorial which guides you through a sample debugging session. The tutorial is followed by a reference section which you should read after completing the tutorial. DEBUGGER TUTORIAL The debugger tutorial follows the same format as the general tutorial in chapter 2. You should complete (or at least review) the general tutorial before taking the debugger tutorial. This tutorial will use a program file provided with your ASIC compiler package called "DBGTUTOR.ASI". If you are running from a hard disk, make sure it is in the ASIC directory. If you are running from a two-floppy system, make sure it is on the diskette in drive b:, with the compiler in drive a:. NOTE: Floppy disk users should verify that the ASIC compiler diskette is in drive A: and the "DBGTUTOR.ASI" disk is in drive b: before proceeding. Let's get started: FLOPPY TYPE--> A: <enter> ASIC B:DBGTUTOR <enter> HARD TYPE--> C: <enter> CD C:\ASIC <enter> ASIC DBGTUTOR <enter> Page - 22 You should be in ASIC now, and you should see a source program. The first few lines should contain: dim scores(10) data 55,33,877,99,44,101,21,88,105,1 rem DBGTUTOR.ASI . . (etc) . This sample program will sort an array of 10 scores into ascending sequence. It uses a simple "bubble" sort algorithm. The "bubble" sort algorithm simply steps through each element of the array and compares it to its next higher neighbor. If its neighbor's value is less than its own, the two values are swapped. It is necessary to execute this process N-1 times where N= number of items to sort. Here's why. Let's say the lowest value to be sorted was "1" and it is in array element "10" (assume 10 numbers will be sorted). The first swapping pass will result in the "1" being swapped from element 10 to element 9 of the array. An additional 8 passes through the array are necessary to move the "1" to array element number 1. This algorithm gets its name, because the process of moving the elements has been compared to that of bubbles slowly rising to the surface. This program has a list of ten scores to be sorted. Line 5 of the program will read the ten scores to an array called "Scores", and also print the original values (before the sort) to the screen. Then two loops will execute at statements 8 and 9 in the program to perform the bubble sort as described above. Finally, after the sort is complete, the sorted values will be displayed. First, let's compile the program. When we plan to use the debugger, we must set the "Debugging code" option on. This is done on the Compile Menu. However, the default in the integrated environment is "Debugging code" on. Let's take a look to be sure: TYPE--> <Alt><c> The compile menu should pop open, and you should see a check mark next to the "Debugging code" option. If you don't, press the letter "D", and a check mark should appear. Once you've verified that the option is on, we can compile the program. Notice that there is an <F10> next to the option. Instead of opening this menu and selecting the "Compile" option, we could have pressed <F10>. Let's try it. First, let's close the menu (Function keys don't work inside a menu): TYPE--> <ESC> The menu should have closed. Now let's compile using the function key: TYPE--> <F10> You should see the compiler screen pop up, and compile the program. No errors should be detected. Now we're ready to test the program. First, let's set a breakpoint so we can easily view the screen output, Use the Page - 23 down arrow key to position the cursor on line 20 (the line number is displayed on the ASIC status line). Line 20 should contain an "END" statement. Let's open the run menu and set a breakpoint: TYPE--> <Alt><r> <b> The "END" statement should now be displayed in reverse video. That tells us that a breakpoint has been set there. Did you notice that the breakpoint option on the menu also had a function key listed. We could set a breakpoint without opening a menu, by pressing <F9> instead. Now that we've set a breakpoint, let's run the program and see how it works: TYPE--> <Alt><r> <r> Note that we could have pressed the short cut key of <F5> to run the program instead of selecting the option from the menu. At this point our program is running, but is paused at the breakpoint we set on line 20. When you reach a breakpoint, ASIC will position the breakpointed line on the second line of the edit window, highlighted in red (or underlined, if you have a monochrome system). ASIC has interrupted the program before it executed the line with the breakpoint, in this case "END". Let's take a look at the screen output of the program to see if it worked: TYPE--> <Alt><r> <s> Note we could also select the "Swap" function by pressing <F4> without opening a menu. You should now see the output from the program on the screen. It should look something like: Original Scores: 55 33 877 99 44 101 21 88 105 1 Sorting... Here are the sorted scores: 33 55 99 44 101 21 88 105 1 877 Well, that doesn't look quite right. Maybe we can use the debugger to figure out what went wrong. First, let's allow the program to run to completion (remember, we're paused at a breakpoint on the "END" statement). Swap back to the ASIC screen from the user screen by pressing any key: TYPE--> <enter> You should see the editor screen again. Now let's tell ASIC to resume program execution: TYPE--> <Alt><r> <r> ASIC has executed the END statement, and our program has terminated. You should see the message "Program Terminated Normally (0)". (The "0" is the return code set by the program. You can set return codes in your Page - 24 programs using the END statement. Refer to Chapter 7 for details.). Now we'll set another breakpoint in the program. Move the cursor to line 7 (the status line should now say LINE: 7) using the arrow keys. The cursor should now be positioned on the statement which says: PRINT "Sorting...". Set a breakpoint here: TYPE--> <F9> The source statement should now appear in reverse video. We used the shortcut key <F9> to set the breakpoint this time, but you could have opened the Run Menu, and selected the Breakpoint option and done the same thing. Let's remove the breakpoint: TYPE--> <F9> Line 7 should no longer be highlighted. The same command is used to turn breakpoints on or off for a source line. ASIC just checks to see if a breakpoint is already set at that source line when you select the breakpoint command. If one is set, it "toggles" it off (ie removes it), otherwise, it "toggles" it on (ie sets a breakpoint). This exercise was just to show you how to remove a breakpoint, let's go ahead and set it again: TYPE--> <F9> Line 7 should be highlighted again (the breakpoint is set). It might be nice to see what's in some of our program's variables, so let's "watch" some variables. Open the Run Menu, select the Watch command, and tell ASIC you want to watch variable "I". TYPE--> <Alt><r> <w> i<enter> ASIC should have opened a "Watch" window at the bottom of the screen. You should see the variable name "I" at the left, followed by a ":". Following the ":" is the current value of that variable. The number there now doesn't really mean anything, since our program is not running. But once the we start the program, this number should represent the actual value of the variable "I". Let's watch a few more variables: j, j1, and scores(1). This time, we'll use the shortcut key for the watch command: TYPE--> <F6> j<enter> Variable "J" should now be in the watch window. TYPE--> <F6> j1<enter> Variable "J1" should now be in the watch window. When we watch "scores", we'll also have to tell ASIC which element we want to watch by entering a subscript, since "scores" is an array. First ASIC will prompt you for the variable name. Type it, without the subscript. ASIC will prompt you for the numeric subscript. Page - 25 TYPE--> <F6> scores<enter> <1><enter> Scores(1) should now be in the watch window. Now we're ready to run the program again: TYPE--> <F5> Again we selected the short cut key, you could have selected the "Run your program" option from the "Run" Menu. The second line of the edit screen should show the PRINT "Sorting..." statement (highlighted in red, or underlined if you have a monochrome monitor). The variables in the watch window should have the following values: I: 11 J: 0 J1: 0 SCORES(1): 55 Let's execute the next statement by using the Trace command: TYPE--> <Alt><r> <t> ASIC has executed the PRINT "Sorting..." statement and has paused execution on the "FOR I" statement on line 8 of the program. Since the PRINT statement did not modify any variables, the numbers in the watch window should remain unchanged. Let's Trace one more statement, this time, we'll use the short cut key: TYPE--> <F8> ASIC has executed the "FOR I" statement on line 8, and is now paused on statement "FOR J" on line 9 of the program. Something looks wrong though. Even though we executed the first "FOR I" statement, the variable "I" still contains "11". It should contain "1". If you look at line 8, you'll see that the FOR statement was mistyped, it reads: "FOR I = I to 9", instead of "FOR I=1 to 9". Since the program also used variable "I" to READ the data into the array, "I" still contains the value "11". Since "11" is greater than the "TO" value of the "FOR" loop, the FOR loop on line 8 is executed only 1 time instead of 9 times. That's why the data is not being fully sorted. With the ASIC debugger, we can continue testing without recompiling, by modifying the value of "I" to "1", so we can see if the rest of our logic is correct. If changing "I" to "1" works, then we can go back and modify the "FOR" statement and recompile the program to correct the program permanently. Modify the value of "I" to "1": TYPE--> <Alt><r> <m> i<enter> <1><enter> Page - 26 The watch window should now show the value of "I" as 1. We can resume program execution at this point by selecting the "Run your program" option. We'll use the short cut key again: TYPE--> <F5> ASIC should pause the program at the next breakpoint, which is on line 20. This statement contains the "END" command. Now let's see if the program worked, by swapping to the user screen: TYPE--> <F4> Again, we used the short cut key. You should see the following on your screen: Original Scores: 55 33 877 99 44 101 21 88 105 1 Sorting... Here are the sorted scores: 1 21 33 44 55 88 99 101 105 877 It looks like the program worked. Let's return to the editor screen. TYPE--> <enter> Now we could press <F5> to resume execution and in this case terminate, since the END statement is the next one to execute. But let's look at another way to terminate a program. While at a breakpoint, you can select the "Abort your program" option, which instructs ASIC to terminate your program immediately, without executing any more of your program. Let's try it: TYPE--> <Alt><r> <a> ASIC should display the message "Program Terminated Normally (0)". At this point, we'll just exit from ASIC, but normally, you would fix the FOR statement using the editor, save the file, recompile the program, and retest it to make sure the "bug" is really fixed. TYPE--> <Alt><f> <x> You should be back at the DOS prompt now. That concludes the brief introduction to the ASIC debugger. The rest of this chapter provides some additional reference material for the debugger. Chapter 3 provides additional information about each of the debugging commands. Page - 27 DEBUGGER TIPS 1) WHEN YOU ARE DONE DEBUGGING YOUR PROGRAM, YOU SHOULD RECOMPILE WITH THE "DEBUGGING CODE" OPTION TURNED OFF. Although your program can run from the DOS command line with debugging code present, it will increase the program size and execution times. Recompiling with the "Debugging code" option off will insure your programs will be smaller and faster. 2) Remember that the default option on the command line compiler is "Debugging code" off. The default option in the integrated environment is "Debugging code" on. 3) Breakpoints/Watches are automatically cleared when you OPEN or COMPILE a file. 4) If you change source lines in a program while a program is running, without recompiling, source statements will not match executable code. Abort the running program and recompile after making code changes. 5) Breakpoints are set in the edit buffer relative to the beginning of the buffer. If you insert/delete lines in the buffer, the breakpoints will still be set at the same relative line number from the beginning of the buffer. 6) ASIC takes over the INT 3 Interrupt vector for debugging purposes. It re-installs the default vector when you exit ASIC. 7) You must compile with the "Debugging code" option to use source level debugging. 8) If you wish to run a program from the beginning again while its already running, select the "Abort your program" option from the Run menu. Then, select the "Run your program" option. 9) If you select the Abort option from the Run menu, your program's files will NOT be closed gracefully. That is, data in the buffers will not be flushed to disk. 10) You may still run a program in the integrated environment that has been compiled without the Debugging code option. You just won't be able to use the debugging commands (eg, Breakpoints/Watches). 11) Toggling a breakpoint on/off will clear any block of text you had previously marked for editing (eg, MOVE, COPY). Page - 28 DEBUGGER TIPS (Continued) 12) When modifying array variables, make sure that the subscript you specify is valid. For example, if you "DIM A(10)", make sure the subscript you specify is in the range of 0 to 10. ASIC does not check the range of a subscript. If you specify a subscript that exceeds the valid range for that variable, your program may crash. 13) You can pass arguments to programs using the "Arguments" option on the Run Menu. You may retrieve these options in your program with the COMMAND$ statement. Using the "Arguments" option is equivalent to specifying arguments following the program name, when you run your program from the DOS command line. 14) The compiler allows variable names up to 80 characters in length. The debugger only uses the first 30 characters of a variable name. When the debugger finds two variables whose names are not unique within 30 characters, it will always select the first one it finds (this applies to the Watch/Unwatch/Modify Variables commands). 15) ASIC will allow you to set a breakpoint on a "FOR" statement. However, you should be aware that the source statement containing the "FOR" is executed only once (to initialize the loop). When the "NEXT" statement executes, control transfers back to the line following the "FOR", instead of the "FOR". For example, in the following code fragment: FOR I = 1 TO 3 <---Executes 1 time to initialize loop PRINT I <---Executes 3 times A=A+1 <---Executes 3 times NEXT I <---Executes 3 times, loops back to "PRINT I", not to "FOR I= 1 TO 3" 16) Because a single machine language instruction could span multiple CODE statements, ASIC does not allow breakpoints on CODE statements. Page - 29 A S I C Chapter 5 Compiler Options COMMAND LINE SYNTAX Invoke the command line version of the compiler as follows: ASICC filename option1 option2 option3[...option7] Where: filename is the name of the source program to be compiled. This file must have the file extension ".ASI", although the extension may be omitted from the command line. optionN specifies any options desired. No options are required, but as many as seven may be specified. COMPILER OPTIONS A total of six compiler switches are currently available for ASIC. Each is described in detail below: Switch Description C CONTINUE--ASIC will not pause after messages are issued, but will continue compiling. Default: ASIC will pause after each error message. Compilation will resume after you press a key. Page - 30 COMPILER OPTIONS (Continued) Switch Description L LIST ALL--ASIC will list each source line as it compiles it. Default: ASIC will list only source lines with compile errors. Comment: Use of this switch will slow compile speeds slightly due to the additional screen I/O. P PRINTLIST--ASIC will echo all messages which appear on the screen to the printer. Output to the printer will be paged with header lines identifying the program name, and the date/time compiled. Default: ASIC will not send any messages to the printer. Comments: Even though output to the printer is buffered, this option will slow compile speeds considerably. The compiler typically compiles only as fast as your printer can print the messages. An alternative to this switch is the DISKLIST option described below. D DISKLIST--ASIC will echo all screen messages to a disk file named "progname.LST". The format is the same produced by PRINTLIST. This allows you to compile at higher speed, and print the source listing later from the disk file via the DOS print spooler. Default: ASIC does not produce a ".LST" file. S SYMTAB----ASIC will produce a formatted Symbol Table in a file named "progname.SYM". The symbol table contains a list of all variables, labels, and internally created compiler addresses. Default: ASIC does not produce a ".SYM" file. Page - 31 COMPILER OPTIONS (Continued) E EMATH-----ASIC will enable the Extended Math Option. When this option is selected, you may specify long integers (eg, VELOCITY&, 123456789&, etc) which can hold a larger range of values (+2,147,483,647 to -2,147,483,647). This option does increase the size of your ".COM" file by a couple of hundred bytes. Default: ASIC does not enable the Extended Math Option. X DEBUG-----ASIC will generate debugging code in the ".COM" file and a ".DBG" file for use by the integrated environment debugger. Default: ASIC does not generate debugging information. Comment: If you are running from the integrated environment, ASIC sets this option on by default. You may turn it off in the Compile menu, should you so desire. COMPILE EXAMPLES Example 1: Compile "MYFILE.ASI" with default compiler options: ASICC MYFILE Example 2: Compile "MYPROG.ASI", Listing all source lines, writing a compile listing to a disk file for printing later. The listing file will be called "MYPROG.LST": ASICC MYPROG L D Example 3: Compile "FILEX.ASI", don't pause for any errors, and print the errors on the printer: ASICC FILEX C P Example 4: Compile "CRUNCH.ASI" and allow long (32 bit) integer numbers: ASICC CRUNCH E Page - 32 A S I C Chapter 6 Language Elements CHARACTER SET Symbol Description * Multiplication Example: A=B*C (multiply B by C, store result in A) / Division Example: A=B/C (divide B by C, store result in A) + Addition Example: A=B+C (add C to B, store result in A) + String Concatenation Example: A$="AB"+"C" (A$ will contain "ABC") = Assignment Example: A=1 (A will be assigned the value 1) = Equality testing Example: IF A=1 THEN QUIT: (If the value stored in (A equals 1 goto label QUIT) - Subtraction Example: A=B-C (Subtract C from B, store result in A) " String Delimiter Example: A$="the string is inside quote marks" () Parenthesis -- Ignored by ASIC Symbol Description ; Suppress Carriage Return/Line Feed with PRINT/LPRINT # Used to identify file usage with PRINT#/INPUT# , Comma, Ignored by ASIC $ Distinguishes a String Variable from an Integer. Example: ABC$ <---- String Variable Example: ABC <---- Integer Variable Page - 33 CHARACTER SET (Continued) Symbol Description : Distinguishes a Label from a variable name. Example: START: <---Label name & Distinguishes a "long" (32 bit) integer from a normal integer (16 bit) variable or constant. Normal integers can hold numbers in the range +32,767 to -32,767. Long integers can hold numbers in the range +2,147,483,647 to -2,147,483,647. Note: You must compile with the "Extended Math" Option enabled to use long integers. Example: APPLES& <--Long Integer Variable Example: ORANGES <--Normal Integer Variable Example: 123457& <--Long Integer Constant Example: 1234 <--Short Integer Constant Page - 34 CONSTANTS, VARIABLES, AND LABELS ASIC supports the following data types: Integer Constants, Integer Variables, Long Integer Variables, Long Integer Constants, single dimension Integer Arrays, single dimension Long Integer Arrays, String Constants, and String Variables. Constants may be specified in decimal (base 10), hexidecimal (base 16), or binary (base 2). The following describes the restrictions for each data type. INTEGER CONSTANTS Range +32767 to -32767 Example: -26 INTEGER VARIABLE Described by a variable name beginning with a letter, followed by up to 79 additional letters or numbers. It may contain a number in the range +32767 to -32767. Example: VELOCITY1 INTEGER ARRAY Described by a variable name beginning with a letter, followed by up to 79 additional letters or numbers. This name is followed by an integer variable or constant for the dimension of the array. Arrays must be dimensioned at the beginning of the program. See the DIM statement. Example: GROWTH (YEAR) LONG INTEGER Range +2,147,483,647 to -2,147,483,647 CONSTANTS Example: 3234457& LONG INTEGER Described by a variable name beginning with a VARIABLE letter, followed by up to 78 additional letters or numbers terminated with a "&". Can contain numbers in the range +2,147,483,647 to -2,147,483,647. Example: VELOCITY1& LONG INTEGER Described by a variable name beginning with a ARRAY letter, followed by up to 78 additional letters or numbers, terminated with a "&". This name is followed by an integer variable or constant for the dimension of the array. Arrays must be dimensioned at the beginning of the program. See the DIM statement. Example: GALAXY& (BILLIONSOF) Page - 35 CONSTANTS, VARIABLES, AND LABELS (Continued) HEXIDECIMAL Hexidecimal constants are constants which are CONSTANT stated in base 16 instead of base 10 like normal constants. These may be specified wherever you can specify a decimal constant. Hexidecimal constants in ASIC must be prefixed by "&hex". This prefix should be immediately followed by a valid normal or long integer constant. Hex constants may contain up to 8 hexidecimal digits for long constants, and 4 hexidecimal digits for normal constants. Example: &hexB000 <--equivalent to -20400 Example: &hexB& <--equivalent to 11& Example: &hexFFFFFFFF& <--equivalent to -1& Example: &hexB000& <--equivalent to 45056& BINARY CONSTANT Binary constants are constants which are stated in base 2 instead of base 10 like normal constants. These may be specified wherever you can specify a decimal constant. Binary constants in ASIC must be prefixed by "&bin". This prefix should be immediately followed by a valid normal or long integer constant. Binary constants may contain up to 32 binary digits for long constants or 16 binary digits for normal constants. Example: &bin10 <--equivalent to 2 Example: &bin10101011& <--equivalent to 171& STRING CONSTANT A group of 0-80 characters enclosed by quotation marks. Example: "This is a String Constant" STRING VARIABLE Described by a variable name which begins with a letter, followed by up to 78 additional letters or numbers, terminated with a "$". Can contain 0-80 characters. Example: ADDRESS$ LABEL A Label is a location in your program you wish to transfer to. It must begin with a letter, and it may contain up to 78 additional letters or numbers. It must be terminated with a ":". Example: START: Page - 36 VARIABLES VS. CONSTANTS In general, ASIC will allow the use of either variables, arrays, or constants as operands to any program statement. For example: PRINT CASH PRINT 20 PRINT A(10) All three of the above examples are valid. The only case where a constant cannot be used, is where the value is being modified. For example: A = A + B <----VALID 17 = A + C <----INVALID Of course you must specify the correct data type for the ASIC keyword. For example: A = ABS("HELLO") <----INVALID This statement is invalid because you cannot take the absolute value of a string! There are a few ASIC statements which will accept only integer constants for some operands (DIM, OPEN, PRINT#, INPUT#). Refer to the individual statement for more information. Finally, there is a restriction on the use of subscripts for Arrays. A subscript for an array cannot be another array. For example: A(I(1)) <----INVALID A(I) <----VALID Page - 37 CONVERSION BETWEEN LONG/NORMAL INTEGERS Long or normal integers may be used on any ASIC statement in any combination. Consequently, in the "Keyword Reference" Chapter of this is manual, operands are identified only as "integer". "Integer" in this context should be interpreted as meaning that the operand for that statement can be any of the following: integer constant, integer variable, integer array, long integer constant, long integer variable, or long integer array. Exceptions, if any, are noted in the documentation for the statement. If you do mix long and normal integers in a statement, you should be aware of how ASIC converts between the two formats. The following two rules are applied: 1) If a long integer variable or constant is being stored in a normal integer variable, the long integer (32 bit) number will ALWAYS convert correctly to a normal integer (16 bit) value, provided the long integer variable contains a number which will fit in a normal integer (ie, within the range of +32767 to -32767). If, however, the number is outside of this range, ASIC will truncate it to make it fit in a normal integer. This truncation will cause some surprising (but predictable) answers. For example if "A&" contained the value "50000&", and the following ASIC statement was executed "A=A&", then the value of "A" would be "-15536". The reason that the overflow results in such a strange number is due to the way the IBM PC stores numbers in binary format and is too complicated to describe here. The important thing to remember is, for ASIC to convert from long integers to normal integers correctly, the value in the long integer should be in the range of +32767 to -32767. 2) If a normal integer variable or constant is being stored in a long integer variable, ASIC will always convert the number correctly. Page - 38 A S I C Chapter 7 Keyword Reference ABS Format: integer1 = ABS (integer2) Description: This function returns the absolute value of integer2 which is then stored in integer1. Example: A = ABS (-7) After execution of this statement, "A" will contain 7. ASC Format: integer1 = ASC (string1) Description: This function returns the ASCII value of the first character of string1, storing the result in integer1. Example: A = ASC("123") After execution of this statement "A" would contain 49, which the is ASCII value of "1". Page - 39 BEEP Format: BEEP Description: This statement will cause a short "beep" to be produced on the PC speaker. Example: IF A>99 THEN BEEP PRINT "Number is too big!" A=99 ENDIF The preceding program fragment will check to see if variable "A" contains a value less than 100. If it does not, it will produce a short "beep", display a message, and set the value of "A" to 99. Page - 40 BLOAD Format: BLOAD string1, integer1, integer2 Description: This function loads data previously saved by BSAVE from a file to memory. String1 should be the name of the file previously created by BSAVE. Integer1 should be the memory offset to load the data to. Integer2 should be the number of bytes to read from the file (in the range of 1 to 32767). If DEFSEG has been set, it will be used as the data segment, otherwise, the default ASIC data segment will be used. Example: DEFSEG = &hexB800 BLOAD "SAVED.DAT" 0 100 After execution of these statements 100 bytes will be read from the file "SAVED.DAT" and stored in memory start at 0 bytes from the start of the override data segment (which in this case happens to point to the beginning of video memory for a CGA card). Assuming a CGA card was present, the first 50 characters on the screen would contain data read from the file (don't forget that each screen character is represented by two bytes data and attribute, that's why only 50 characters will be displayed, assuming you are not in graphics mode). Comments: THIS FUNCTION IS RECOMMENDED ONLY FOR ADVANCED PROGRAMMERS. THIS STATEMENT WILL ALLOW YOU TO OVERLAY ANY AREA OF MEMORY, AND IT IS VERY EASY TO ACCIDENTALLY OVERLAY YOUR PROGRAM OR THE MEMORY USED BY DOS. If ASIC detects an error executing this command, it will set the system ERROR variable. These error codes are listed in the Error Messages Chapter of the ASIC Manual This statement is slightly different from GWBASIC/BASICA in that you must specify how many bytes to read from the file. Also, the memory offset is not stored in the file by BSAVE, so you must specify the offset as integer1 in ASIC. Offset is optional in GWBASIC/BASICA. ASIC uses a slightly different file format than GWBASIC/BASICA, however, it is relatively easy to convert the GWBASIC/BASICA to ASIC format. GWBASIC/BASICA files have a seven byte header that ASIC does not have. If you strip off these 7 bytes and rewrite the file, ASIC should be able to process the file. See also: DEFSEG,BSAVE Page - 41 BSAVE Format: BSAVE string1, integer1, integer2 Description: This statement writes the block of memory beginning at offset integer1 from the start of the data segment for a length of integer2 bytes to the file specified by string1. This data may be later loaded by BLOAD. If DEFSEG has been set, it will be used as the data segment, otherwise, the default ASIC data segment will be used. Integer2 should be in the range of 1 to 32767. Example: DEFSEG = &hexB800 BSAVE "SAVED.DAT" 0 4000 After execution of these statements 4000 bytes at offset 0 bytes from the start of the override data segment (which in this case happens to point to the beginning of video memory for a CGA card) will be written to the file "SAVED.DAT". Assuming a CGA card was present, the current screen would be saved to disk, assuming you are not in graphics mode. Comments: If ASIC detects an error executing this command, it will set the system ERROR variable. These error codes are listed in the Error Messages Chapter of the ASIC Manual. See also: DEFSEG,BLOAD Page - 42 CALL Format: CALL (string1,string2) Description: This function can be used to load and execute other programs compiled with ASIC or another compiler. String1 represents the name of the program to execute. String2 contains any arguments to be passed to the program (it may be NULL, ie ""). If an error occurs when ASIC attempts to call the program, it will set the system ERROR variable to 255. Otherwise, the ERROR variable will be set to the value of the return code of the called program (which is 0 unless the called program specifies otherwise). Example: CALL ("MYPROG.COM","") REM other code follows This statement would cause ASIC to load and execute the program "MYPROG.COM". No arguments will be passed to the program. When MYPROG terminates, the calling program will regain control on the line following the call, in this case the "REM" statement. Example 2: CALL ("COMMAND.COM"," /C WP.BAT") In this example, a ".BAT" type file is executed called "WP.BAT". To run ".BAT" files, it is necessary to load a copy of COMMAND.COM as shown above (COMMAND.COM contains the DOS code required to load and execute ".BAT" files). Using this format, you can also run some "built in" DOS commands such as DIR or SORT. Using CALL with this format, is similar to using the GWBASIC/BASICA SHELL command. Comments: String1 must contain the FULL pathname of the program (ie,"\directory\progname.COM") only if the program is NOT in the current directory. You must include the file extension on the file name (for example, use "MYPROG.COM" instead of just "MYPROG", or use "MYPROG.EXE" instead of "MYPROG"). If you wish to pass arguments to the program build it as follows: YOURPARM$ = "arguments" N = LEN(YOURPARM$) A$ = CHR$(N) A$ = A$ + YOURPARM$ B$ = CHR$(13) A$ = A$ + B$ CALL "progname" a$ Page - 43 CALL (Continued) The above creates an argument list according to the strict DOS calling rules, however, you can just create the arguments in a string, and precede them with a leading space. This will work for arguments up to 32 characters in length (space character is ASCII 32). You might want to try this short cut first, and only resort to the full formal approach if you have problems with it, or need to specify longer arguments: CALL "progname" " arguments" CAUTION: You may use the debugger with programs which contain "CALL" statements. However, the programs you call should not themselves contain debugging code. For example, if A.ASI calls B.ASI, then make sure you compile B.ASI with the "Debugging Code" option OFF before you try to debug program A.ASI. Failure to do so will cause the debugger to behave erratically. This also applies to programs you write using other compilers, since they also use the same interrupt as ASIC (INT 3). See also: RUN,COMMAND$ CHDIR Format: CHDIR string1 Description: This statement will change the current directory to that specified in string1. If an error occurs when ASIC executes this command, it will set the System ERROR variable. A list of possible error codes is listed in the Error Messages Chapter of the ASIC Manual. Example: CHDIR "\DOS" IF ERROR = 0 THEN NOERROR: If Drive "C" was the current drive, then this statement would change the current directory to "C:\DOS". CHDIR "C:\DOS" This statement would change the current directory on drive C to "C:\DOS" whether or not drive C is the current drive. It would NOT change the default drive to "C". Note that DOS retains a current directory for each disk drive on your computer. See also: MKDIR, RMDIR Page - 44 CHR$ Format: string1 = CHR$(integer1) Description: This function converts an integer in the range of 0-255 to an ASCII character, and stores in string1. Example: A$ = CHR$(49) After execution of this statement, "A$" will contain "1", since "1" is represented by ASCII 49. Comments: If integer1 is outside the range 0-255, then the least significant byte of integer 1 is converted to string1. CLOSE Format: CLOSE integer1 Description: This function closes the file number identified by integer1. If an error is returned by DOS, the system variable "ERROR" will be > 0. Example: CLOSE 1 IF ERROR > 0 THEN CHECKERROR: After successful execution of the CLOSE statement, the file previously opened as file 1 will be closed. If an error is returned by DOS, the ERROR variable will be set by ASIC to a non-zero value. Comments: IF YOU FAIL TO CLOSE AN OPEN FILE (WHICH WAS OPENED FOR WRITING), YOU MAY LOSE DATA, SINCE FILE I/O IS BUFFERED, AND THE LAST BUFFER MAY NOT HAVE BEEN FLUSHED. Also, integer1 may only be a constant with the value of 1-3. See Also: OPEN,PRINT#,INPUT# Page - 45 CLS Format: CLS Description: This function clears the screen. Example: CLS After execution of the above statement, the screen will be cleared. CODE Format: CODE integer1[,integer2...integerN] Description: This function may be used to insert machine language code directly into your program. Integer1 through integerN should be constants in the range of 0-255. At least one integer must be specified, however, ASIC will allow up to 30. Example: CODE 205,5 This statement represent the machine code generated from the assembly language statement "INT 5". INT 5 is the BIOS routine which will print the screen to the printer. After execution of these statements in your program, the current screen contents would be printed on your printer. Comments: THIS STATEMENT IS INTENDED FOR ADVANCED PROGRAMMERS. THIS STATEMENT IS VERY POWERFUL, AND IF YOU DON'T UNDERSTAND MACHINE LANGUAGE YOU COULD EASILY CRASH YOUR PROGRAM. When you use this statement, be sure to save the contents of the following 8088 registers if you plan to modify them, and restore them before returning to ASIC. Otherwise the results may be unpredictable. Registers: DS/CS/ES/SS. Also, make sure you clean up the stack before you return (ie, if you push a value to the stack, make sure you pop it before you return to ASIC) Failure to do so, will almost certainly cause your program to crash. Page - 46 COLOR Format: COLOR integer1,integer2 Description: This function is used to set the foreground and background screen colors. The foreground color is specified in integer1, the background color in integer2. Valid Colors: Foreground Background ---------- ---------- Black 0 0 Blue 1 1 Green 2 2 Cyan 3 3 Red 4 4 Magenta 5 5 Brown 6 6 White 7 7 Dark Gray 8 Light Blue 9 Light Green 10 Light Cyan 11 Light Red 12 Light Magenta 13 Yellow 14 Bright White 15 Note: Colors 8-15 when specified for background color result in blinking text. Example: COLOR 4,8 After execution of this statement, future characters written to the screen will be Blinking Red on a Black Background. Page - 47 COMMAND$ Format: string1 = COMMAND$ Description: This statements retrieves any command line arguments that were entered and stores them in string1. Example: If your program was invoked with: MYPROG XXX And if your program MYPROG.ASI contained the following: A$=COMMAND$ PRINT A$ After execution of these statements, the screen would display " XXX". Comments: In the integrated environment, you can specify command line arguments on the "Run" Menu. This statement is an extension over BASICA/GWBASIC. Page - 48 COMSTAT Format: integer1 = COMSTAT (integer2) Description: This statement returns the status of a com port. Integer2 should contain "0" for COM1, or "1" for COM2. The status of that COM port is returned in integer1. Each bit in integer1 represents a different piece of information. These are described in the table below. Note that you may test if a bit is on/off using the ZBIT command. Example: PORTSTAT = COMSTAT (0) DATAREADY = ZBIT(8,PORTSTAT) IF DATAREADY = 1 THEN GORECEIVE: These statements do the following. The first retrieves the status of COM1 to the variable PORTSTAT. The second checks to see if bit 8 is on, DATAREADY will contain 1 if so, otherwise it will contain 0. Since Bit 8 is used to determine if data is waiting to be received from the port, if DATAREADY = 1 then the program will transfer to the label GORECEIVE: which would contain code to RECEIVE data from the port. Comments: Status Codes Returned by COMSTAT (Meaning when set to 1) Bit 0 Delta clear-to-send 1 Delta data-set-ready 2 Trailing-edge ring detector 3 Delta receive line signal detect 4 Clear-to-send 5 Data-set-ready 6 Ring Indicator 7 Received line signal detect 8 Data Ready 9 Overrun error 10 Parity error 11 Framing error 12 Break-detect error 13 Transfer holding register empty 14 Transfer shift-register empty 15 Time-out error See also: OPENCOM,SEND,RECEIVE Page - 49 CSRLIN Format: integer1 = CSRLIN Description: This function returns row of the cursor. Example: LOCATE 10,20 A = CSRLIN The locate command will have positioned the cursor in row 10, column 20. After execution of the CSRLIN statement, "A" will contain the value of 10. See also: POS Page - 50 DATA Format: DATA constant1[,constant2,...,constantn] Description: This statement is used store integer and string constants in memory for later retrieval by READ statements. At least one integer or string constant must be specified, although multiples of each type are permitted. Example: DATA 1,"APPLE",2&,"ORANGES" READ A READ A$ READ B& READ B$ The above statements are equivalent of entering the following code: A=1 A$="APPLE" B&=2& B$="ORANGES" Comments: All DATA Statements must be placed at the beginning of the program, before all other statement types, except DIM or REM statements (or blank lines). DIM statements, if specified, must precede all other statements including DATA statements except REM statements (or blank lines). As long as you follow these rules, you may specify an unlimited number of DATA statements. GWBASIC/BASICA does not require quotes around string constants in some instances. ASIC always requires quotes around string constants. See also: READ,RESTORE Page - 51 DATE$ Format: string1 = DATE$ Description: This function returns the value of the system date in the format of "MM-DD-YYYY". Example: A$=DATE$ PRINT A$ After executing these statements, the date stored in the PC System Clock will be displayed on the screen. Comments: Note: if the date printed is wrong, you have probably not set the system clock. Most older XTs and PCs do not have a battery to preserve the DATE and TIME in the system clock, so you have to set them each time you power up the PC. Most ATs and newer PCs have a battery backup, so that the date is preserved for you. Unlike GWBASIC/BASICA, you cannot set the system date with DATE$, however, you can set the system date from DOS by typing DATE. See also: TIME$, TIMER DEFSEG Format: DEFSEG = integer1 This function is used the alter the default data segment used when peeking and poking data with PEEK and POKE statements. DEFSEG, PEEK, and especially POKE are not recommended for beginners. If integer1 =-1, then the data segment address is set back to the ASIC default data segment address. Example: DEFSEG = -1 Execution of the above statement would reset the default data segment to the default ASIC data segment. See also: PEEK, POKE, BLOAD, BSAVE Page - 52 DIM Format: DIM variable(integer1) Description: This statement will create one dimensional arrays. An integer variable name must be specified in variable. Integer 1 contains the number of elements in the array. Example: DIM A(10) DIM A&(20) In this example an array of 10 normal integer variables is defined, and an array of 20 long integer variables is defined. Comments: On the DIM statement, integer1 may only be a constant. Also, DIM statements must appear before all other statement types in the program except REM statements (or blank lines). END Format: END [(integer1)] Description: This statement causes your program to terminate and return to DOS, optionally setting a return code. Integer1 may be optionally specified to set the return code. If omitted, ASIC uses a return code of zero by default. Example: END In this example, the program will terminate and return to DOS with a return code of zero. END (20) In this example, the program will terminate and return to DOS with a return code of "20". Comments: The optional return code is an extension over GWBASIC/BASICA. Page - 53 ENVIRON$ Format: string1 = ENVIRON$(integer1) Description: This statement will retrieve DOS environment strings. Integer1 identifies which string to retrieve. If found, the string is placed in string1. If not found, a NULL string (length=0) is stored in string1. Example: FOR I=1 TO 5 A$=ENVIRON$(1) PRINT A$ NEXT I The above example will retrieve the first five DOS environment strings and display them. Comments: If the requested DOS environment string entry is greater than 80 characters in length, ASIC will truncate it at 80 characters. Environment strings may be set in DOS using the SET command. Environment strings are one way of passing information to your program. Refer to your MS DOS Manual for more information. Page - 54 FILEPOS Format: integer1 = FILEPOS (integer2,integer3) <--Format 1 integer1 = FILEPOS (integer2,EOF) <--Format 2 integer1 = FILEPOS (integer2,CURRENT) <--Format 3 Description: This statement is used to set or retrieve the read/write position for files opened in Random mode. In all three formats, integer2 is the file number of the file. This file number must have been previously opened for Random mode by the OPEN statement. Format 1 is used to set the current read/write position of the file specified by integer2. Integer3 should be the offset (in bytes) from the start of the file. Format 2 is used to set a read/write position of a random file to the end of the file. Format 3 is used to retrieve the current read/write position (as a byte offset from the beginning of the file) of the file. In all cases, if an error occurs, the system ERROR variable will be set. A list of these codes is contained in the Error Codes Chapter of the ASIC Manual. If no error occurs, then integer1 will be set to the current read/write position of the file. Example 1: A&=FILEPOS(1, 100) This example assumes that file 1 was previously opened for RANDOM I/O using the OPEN statement. After execution of this statement, the read/write position of file number 1 will be set to 100. Subsequent PRINT # statements would write to the file starting at position 101. Example 2: A&=FILEPOS(1,EOF) This example assumes that file 1 was previously opened for RANDOM I/O using the OPEN statement. After execution of this statement, the read/write position of file number 1 will be set to the end of the file. Subsequent PRINT # operations to this file will result in data being appended to this file. Example 3: A&=FILEPOS(1,CURRENT) This example assumes that file 1 was previously opened for RANDOM I/O using the OPEN statement. After execution of this statement, the current read/write position of file number 1 will retrieved and stored in integer1. The read/write position of file number 1 will NOT be altered after execution of this statement. Page - 55 FILEPOS (Continued) Comments: If you wish to use this command with files larger than 32767 bytes, you should use long integers with this statement. If you set the read/write position past the physical end of file and attempt to read from the file, you will receive an error on the INPUT# command. If you set the read/write position past the end of file and issue a PRINT# command, the data will be correctly written at the position you specified. See also: OPEN, INPUT#, PRINT#, CLOSE Page - 56 FIND Format: string1=FIND FIRST (string2,integer1) string1=FIND CONTINUE Description: The FIND command is used to search the current file directory for file(s) which match a search string. This command has two versions. FIND FIRST must be used to establish a new search and retrieve the first matching file name. Thereafter, the FIND CONTINUE will retrieve additional file names which match the search string. When performing the FIND FIRST, string2 should contain the full or partial file name to be searched for. This string can be up to 8 alphanumeric characters optionally followed by a period and up to 3 alphanumeric characters for the file extension. Standard DOS wild cards "*" and "?" may be included in the search string. Integer1 is used to specify a file attribute. If integer1 is "0", then all normal files in the directory will be searched. (A normal file is one in which the hidden, system, volume label, or directory attribute bit is NOT set). Setting various bits (see table below) of integer1 ON will expand the search to include normal files, plus those whose attributes have been specified in integer1. If a matching file name is found, then it will be stored in string1. If an error occurs, then the system ERROR variable will be set. A list of ERROR codes is contained in the ERROR code chapter of the ASIC Manual. After the initial FIND FIRST has been performed, you may search for additional files which match the search string and attribute by issuing a FIND CONTINUE statement. Search Attributes bits (integer1) -------------------------------- BIT 0 Not Used 1 Hidden 2 System 3 Volume Label 4 Subdirectory 5-7 Not Used Note that these attributes can all be specified simultaneously. For example, to specify both hidden and system, use an attribute value of &bin00000110 (in binary) or 6 (in decimal). Page - 57 FIND (Continued) Example: SEARCH$="*.ASI" ATTRIB=0 FILENAME$=FIND FIRST (SEARCH$,ATTRIB) IF ERROR>0 THEN DONE: PRINT A$ LOOP:FILENAME$=FIND CONTINUE IF ERROR>0 THEN DONE: PRINT A$ GOTO LOOP DONE: PRINT "ALL MATCHING FILES DISPLAYED" END After execution of the above statements, all of the files with a file extension of ".ASI" in the current directory will be displayed on the screen. Comments: If you execute a FIND CONTINUE without executing a FIND FIRST, then the results are unpredictable. Additional information is retrieved by the FIND command besides the file name. Advanced programmers can also find additional information using the PEEK command starting at offset 149 (from the default ASIC data segment). Do not modify this data. If you do so, the results are unpredictable. Additional File Information --------------------------- Address Size (bytes) Description 149 1 File Attribute 150 2 File Time Stamp 152 2 File Date Stamp 154 4 File Size (bytes) See also: NAME, KILL, GETDIR, CHDIR, MKDIR, RMDIR Page - 58 FOR/NEXT Format: FOR integer1 = integer2 to integer3 NEXT integer1 Description: These two statements are used to create a loop, so that you can execute a portion of your program a certain number of times. All of the code between the FOR and the NEXT statement will be executed a certain number of times, but at least once. The actual number of times the loop executes is dependent on integer1/integer2/integer3. When the FOR statement is encountered in your program, integer1 is assigned the value of integer2. Then the statements up to the matching NEXT statement is executed one time. Then, 1 is added to integer1, and integer1 is compared to integer3. If integer1 is greater than integer3 then the control passes to the statement following NEXT. Otherwise, the program loops back up to the statement following the FOR statement. Example: FOR I = 1 TO 2 FOR J = 3 TO 5 PRINT I; PRINT J NEXT J NEXT I PRINT "AFTER THE LOOP"; PRINT I; PRINT J; Execution of this section of code would result in the following printout: 1 3 1 4 1 5 2 3 2 4 2 5 AFTER THE LOOP 3 6 Comments: Unlike BASICA/GWBASIC, ASIC FOR/NEXT loops execute at least 1 time. For example, the value "HELLO" will be printed in the following example. It wouldn't have been in BASICA/GWBASIC. FOR I = 1 TO 0 PRINT "HELLO" NEXT I Page - 59 FOR/NEXT (Continued) Unlike GWBASIC/BASICA, arrays may be used for integer1 and integer2. However, if integer3 is an array, element zero will be used, regardless of the subscript you specify. ASIC will allow you to modify the value of integer3, while GWBASIC/BASICA ignores changes. J=1 FOR I=1 TO J J=2 NEXT I The above loop will execute one time in GWBASIC/BASICA, but it will execute two times in ASIC. GETDIR Format: string1=GETDIR (integer1) Description: This statement is used to retrieve the current DOS directory. Integer1 should be set to "0" to obtain the directory for the current drive, "1" for the "A" drive, "2" for the "B" drive, etc. If the statement is unsuccessful, the system ERROR variable will be set. A complete list of ERROR codes is contained in the Error Code Chapter of the ASIC Manual. The directory string will be stored in string1. The directory string will not contain the drive letter, or the first "\". Thus, if the current directory on the specified drive was "C:\ASIC", then GETDIR would return "ASIC". If the current directory was the root (eg, "C:\"), then GETDIR would return a NULL string (""). Example: A$=GETDIR(0) After execution of this statement, the variable A$ will contain the name of current directory on the current disk drive. See also: FIND, MDKIR, RMDIR, CHDIR Page - 60 GOSUB Format: GOSUB label1 Description: This statement "calls" a subroutine called "label1". This subroutine must contain a "RETURN". After the subroutine is executed, control is returned to the next statement following the GOSUB. Example: GOSUB PRINTIT: PRINT "All Done!" END PRINTIT: PRINT "It" RETURN After execution of this code the screen would contain: It All Done! GOTO Format: GOTO label1 Description: This statement transfers program execution to the statement identified by label1. Example: GOTO SKIPIT: PRINT "YOU'LL NEVER GET HERE" SKIPIT: PRINT "ALL DONE!" After execution of this code, the screen will appear as follows: ALL DONE! Note that the first print statement never executes because of the GOTO. Page - 61 IF/THEN/ELSE/ENDIF Format: IF condition THEN label1 <--Format 1 IF condition THEN label1 ELSE label2 <--Format 2 IF condition THEN <--Format 3 <zero or more ASIC statements> ENDIF IF condition THEN <--Format 4 <zero or more ASIC statements> ELSE <zero or more ASIC statements> ENDIF Description: This statement is used to conditionally transfer to a different location in the program. The operand "condition" is one of the following: integer1 > integer2 string1 > string2 integer1 = integer2 string1 = string2 integer1 < integer2 string1 < string2 Format 1--If "condition" is true, control is transferred to label1. Otherwise the program continues at the next statement. Format 2--If "condition" is true, control is transferred to label1, otherwise the program branches to label2 and continues execution from there. Format 3--If "condition" is true, the program will continue execution at the next statement. If the condition is false, the program will branch to the statement following the next ENDIF statement encountered. Format 4--If "condition" is true, program will continue execution at the next statement up to the next ELSE statement encountered, at which point it will branch to the statement following the next ENDIF statement encountered. If "condition" is false, the program will branch to the next ELSE statement and resume execution at that statement. Example 1: IF A > 0 THEN APLUS: In this example, if A is greater than zero, the program jumps to the label called "APLUS:". Page - 62 IF/THEN/ELSE/ENDIF (Continued) Example 2: IF A$="YES" THEN TRUE: ELSE FALSE: In this example, if A$ contains the string "YES", the program jumps to the label called "TRUE:", otherwise the program transfers to label "FALSE:" Example 3: OPEN "I",1,"TEST.DAT" IF ERROR>0 THEN PRINT "ERROR OPENING FILE"; PRINT ERROR END ENDIF REM rest of program follows . . In this example, if there is an error opening file "TEST.DAT", the program will print an error message and terminate. Otherwise control will fall through to the REM statement and the program will continue. Example 4: PRINT "ENTER A NUMBER"; INPUT NUMBER IF NUMBER > 100 THEN PRINT "THAT'S A BIG NUMBER" ELSE PRINT "THAT'S A SMALL NUMBER" ENDIF Comments: Formats 3 and 4 are BLOCK IF formats. You can nest BLOCK IF statements up to 25 levels deep. The example below is shown three levels deep. IF A=1 THEN <-Level 1 IF B=2 THEN <-Level 2 IF C=3 THEN <-Level 3 PRINT "C=3, B=2, AND A=1" ELSE PRINT "C<>3, B=2, AND A=1" <-ELSE for Level 3 ENDIF <-ENDIF for Level 3 ENDIF <-ENDIF for Level 2 ENDIF <-ENDIF for Level 1 It's a good idea to indent your IFs, ELSEs and ENDIFs as shown above. Otherwise matching IFs up with matching ENDIFs and ELSEs can become very confusing. Page - 63 INKEY$ Format: string1 = INKEY$ Description: Used to retrieve keystrokes from the keyboard buffer. If a character is waiting in the buffer, string1 will be set to the value of that character, and that character will be removed from the keyboard buffer. If the buffer is empty, string1 will be set to a value of "" (that is, a null string with a length of 0). If an extended key is pressed (for example the function keys F1 through F10), the system variable EXTENDED will be set to 1, otherwise it will contain 0. Example: LOOP: X$=INKEY$ IF X$="" THEN LOOP: The above code will cause the program to loop until a key is pressed. Comment: ASIC provides an extension here over BASICA/GWBASIC. The EXTENDED system variable will allow you to detect special keys as mentioned above. To do so requires an understanding of keyboard scan codes, which is beyond the scope of the ASIC Manual. For more information I would suggest Peter Norton's Programmer Guide to the IBM PC (Microsoft Press). INP Format: integer1 = INP (integer2) Description: This statement reads a byte from port integer2 and stores the result in integer1. Example: A=INP(513) A=ZBIT(4,A) IF A=1 THEN TRIGGERPRESSED: The above code will test the joystick port to see if the trigger is being pressed on joystick 1. You need a game card and joystick for this to work. See also: OUT Page - 64 INPUT Format: INPUT variable1 Description: This statement will retrieve a line of text terminated from the input buffer and stores it in variable1. ASIC will first issue the prompt "?". It will then wait until the user enters a string or integer and presses the <return> or <enter> key. The type of data ASIC will expect is dependent on the type of variable1 (integer or string). If an integer is being entered, ASIC will edit the input for validity as an integer, and if the edit fails will issue another "?" to the user, and will wait for the number to be retyped. Only when a valid integer has been entered will variable1 be updated, and only then will control return to your ASIC program. Example: PRINT "Enter a String"; INPUT A$ ASIC will issue the prompt: Enter a String? It will then wait until you enter a string or press enter. If you pressed enter with no characters A$ would contain "" (ie its length would equal 0), otherwise A$ would contain the string entered. Example: INPUT I In this example ASIC will issue the prompt: ? ASIC will then wait for you to enter a valid number. If you enter an invalid number, say "x", ASIC will reissue the "?" prompt and wait for you to retype your input. Once the input has been edited by ASIC, "I" would contain the number entered. See Also: INKEY$ Page - 65 INPUT# Format: INPUT# integer1, integer1 <-Format 1 INPUT# integer1, string1 <-Format 2 INPUT# integer1, string1 CRLF <-Format 3 INPUT# integer1, string1 NONULL <-Format 4 INPUT# integer1, string1 BYTE <-Format 5 Description: This statement will read a variable from a file identified by file number integer1. It will be stored in integer1/string1. If an error occurs during a read, the system variable ERROR will be set to a non- zero value. The possible errors are listed in the error messages section the of the ASIC Manual. If you read a file past its end, the contents of variable1 are undefined. Five formats of this statement are provided to provide greater flexibility in reading files written by ASIC and non-ASIC programs. The five formats are summarized below: Format 1 -- Read integers from a file previously written by ASIC. Format 2 -- Read strings from a file previously written by ASIC. Format 3 -- Read strings from a non-ASIC file. Assumes the strings (CRLF) will be terminated by a CR/LF (carriage return/linefeed). Note that ASIC still considers a NULL character, if encountered, as an end of string character. Also ASIC terminates the string if 80 characters are read before encountering a CR/LF pair. Format 4 -- Read strings from a file until 80 characters or the end (NONULL) of the file is reached. Note that ASIC still considers a NULL character, if encountered, as an end of string character. Format 5 -- Reads a single byte from a file and stores it in string1. (BYTE) If ASIC has read a NULL byte, the string will be set to NULL and its length will be 0. Example 1: OPEN "I",1,"TEMP.DAT" INPUT#1, A$ IF ERROR=99 THEN ENDOFFILE: In this example, a string will be read from file "TEMP.DAT", and it will be stored in A$. The system ERROR variable is then checked to see if End of file was reached. Note, other ERRORS could also be returned by INPUT#, besides error code 99. Refer to the error messages section for more information. Page - 66 INPUT# (Continued) Example 2: OPEN "I",1,"TEMP.DAT" INPUT#1, A$ NONULL IF ERROR=99 THEN ENDOFFILE: In this example, ASIC will read 80 characters from the file "TEMP.DAT", or up until the next NULL character in the file, which ever comes first. Example 3: OPEN "I",1,"CONFIG.DAT" INPUT#1, A$ BYTE IF ERROR=99 THEN ENDOFFILE: In this example, ASIC will read a single character from the file "CONFIG.DAT", and place it in the variable A$. Example 4: OPEN "I",1,"TEST.DAT" INPUT#1, A IF ERROR=99 THEN ENDOFFILE: In this example, ASIC will read an integer value from the file "TEST.DAT", and place it in the integer variable "A". Example 5: OPEN "I",1,"ASCII.DAT" OPEN "O",2,"ASCII.NEW" CR$=CHR$(13) LF$=CHR$(10) CRLF$=CR$+LF$ READMORE: INPUT #1, A$ CRLF IF ERROR=96 THEN WRITE: IF ERROR>0 THEN ENDOFFILE: WRITEWITHCRLF: PRINT #2,A$ NONULL PRINT #2,CRLF$ NONULL GOTO READMORE: WRITE: PRINT #2, A$ NONULL GOTO READMORE: ENDOFFILE: CLOSE 1 CLOSE 2 This example copies file ASCII.DAT to file ASCII.NEW. Note: Even though ASIC can only handle 80 character strings, this example shows that by checking the ERROR variable for a value of 96, it is possible to read the file in up-to-80-character chunks and reassemble the strings in their original forms in the new file. Also note that ASIC will still treat any NULL characters in the file as an end of string character. Page - 67 INPUT# (Continued) Comments: Note that integer1 must be a constant in the range of 1-3. It identifies a file by file number which must have previously been opened by an OPEN command for modes INPUT or RANDOM. ASIC assumes that integers will be stored in files in 2-byte binary format, which is the format ASIC writes integers. Consequently, If a file contained a string "123", but you told ASIC to read integer "X", then ASIC would read two bytes from the file and interpret "12" as two binary bytes that it would then combine and store as "X". "X" would contain the integer value 12849. Thus to read an integer correctly, you will have had to previously written it with an ASIC program. See Also: OPEN, CLOSE, PRINT#, FILEPOS INSTR Format: integer1 = INSTR (string1,string2) Description: This statement is used to determine if a given substring exists within a string, and if so, the character position at which the substring first appears in the string. String1 is the string to be searched. String2 contains the substring to find within string1. The character position of string2 within string1 is returned in integer1. If the string is not found then integer1 is set to zero. Example 1: A=INSTR("THE QUICK BROWN FOX","QUICK") After execution of this statement, variable "A" will contain the value 5, which is the offset of the string "QUICK" within the string "THE QUICK BROWN FOX". B=INSTR("FOX","HEN") After the execution of this statement, variable "B" will contain 0, since the string "HEN" is not found within the string "FOX". See also: LEFT$, RIGHT$, MID$, LEN Page - 68 INT86 Format: INT86(integer1,AX,BX,CX,DX,DI,SI,BP,DS,ES) Description: This statement is used to call a DOS, BIOS, or custom-written Interrupt. Integer1 must be a constant, and should identify the number of the interrupt to be called. The fields following integer1 represent the CPU registers. For example, ASIC will move the value from the ASIC variable "AX" to the CPU register "AX" prior to performing the interrupt call. After the call, ASIC will move the value from the CPU register "AX" to the ASIC variable "AX". Your ASIC program can then use this "AX" variable just like any other integer variable in the rest of the program. Each of the registers listed (AX,BX,CX,DX,DI,SI,BP,DS,ES) must be included on the INT86 statement in the same order as shown in the Format statement above. The exception to this rule, is that you can substitute "NA" for any register you do not need for the call. The BP register may be used to pass values to the INT86 call, however, unlike all of the other registers, ASIC does not return the value of the BP register following the INT86 call. Example 1: INT86(5,NA,NA,NA,NA,NA,NA,NA,NA,NA) The above example shows the code to perform a screen print to the printer. This example will call INT 5 (BIOS Print Screen Interrupt), pass no parameters to the call, and receive no return values from the call. Example 2: AX=&hex3600 DX=0 INT86(&hex21,AX,BX,CX,DX,NA,NA,NA,NA,NA) PRINT "Default Drive has:" PRINT PRINT "Sectors/Cluster"; PRINT AX PRINT "Available Cluster Count"; PRINT BX PRINT "Bytes/Sector"; PRINT CX PRINT "Total Clusters"; PRINT DX Page - 69 INT86 (Continued) This example show a more complex call to DOS to find out free disk space information for the current drive. DOS Interrupt 21 (hex) function 36 (hex) is used to retrieve this information. The AX register is used to pass the function number. The DX register is used to select the disk drive (0=the default disk drive). Note that the BX and CX registers were included on the call. No parameters are being passed to the call in these registers, however, we'll be receiving information back from DOS in them, so they need to be on the INT86 statement. Since the SI,DI,BP,DS, and ES registers are not needed by the call, they have been substituted with "NA" which you can think of as meaning "Not Applicable" to this call. After the call, the example program will display information about the default disk drive. Comments: This statement is intended for advanced programmers. To use it properly, you must have some knowledge of assembler language, or at least about the CPU registers in the IBM PC. You also need a DOS or BIOS reference manual to identify which registers to pass to each interrupt, and to identify the values to place in those registers. One register was required for ASIC housekeeping after the INT86 call. This is why the BP register is unavailable to receive return values from calls. The BP register was chosen, because none of the DOS or BIOS Interrupts use this register to return values. If you write your own interrupts and want to call them from an ASIC program, remember that you can pass the BP register to the interrupt, but the ASIC "BP" variable will not be updated following the interrupt. If a register is not needed for the call, specify "NA" instead of the register name. ASIC does not generate any code for "NA" registers, and this will reduce the size of your program. Page - 70 KILL Format: KILL string1 Description: This statement is used to delete a file from disk. It is similar to the DOS ERASE Statement. Specify the file to delete in string1. You can specify the full path to the file, or just the file name if it is in the current directory. If an error occurs (eg, File not found), then ASIC will set the System ERROR variable. A list of codes returned by KILL is listed in the ERROR Messages Chapter of the ASIC Manual. Example: KILL "TEMP.DAT" IF ERROR = 0 THEN NOERROR: REM CHECK ERROR CODES HERE After this statement is executed, the file "TEMP.DAT" will have been erased from the current directory of the current drive, and will no longer be accessible from DOS or your programs. LCASE$ Format: string1=LCASE$(string2) Description: This statement will convert all of the letters in string2 from upper case to lower case, and store the result in string1. Example: A$=LCASE$("123 Main Street, USA") After the execution of this statement, the variable A$ will contain the string "123 main street, usa". See also: UCASE$ Page - 71 LEFT$ Format: string1=LEFT$(string2,integer1) Description: This statement will copy integer1 characters from the left of string2 to string1. Example: A$=LEFT$("RED RIDING HOOD",3) After the execution of the above statement, the variable A$ will contain the string "RED". See also: MID$, RIGHT$ LEN Format: integer1 = LEN (string1) Description: This statement returns the length (number of characters) of a string, and stores the length in integer1. Example: A$="abc" LENGTH1 = LEN(A$) After execution of these statements, LENGTH1 would contain 3. Page - 72 LOCATE Format: LOCATE row,column Description: This statement is used to position the cursor to a row and column. Row and Column should be integers. Row has the range 0-24, Column has the range 0-79. This function does not perform edits on the ranges of row and column. Consequently using this function with values outside these ranges will have unpredictable results. Example: LOCATE 10,20 PRINT "HELLO" After execution of these statements, the message "HELLO" will appear beginning at row 10, column 20. LPRINT Format: LPRINT printobject [;] Description: This statement is used to send the contents of printobject to an attached printer. "printobject" can be any valid ASIC datatype: integer constant, integer number, string constant, string variable, and also array elements. Optionally, a ";" can be included with this statement to suppress a carriage return/line feed which ASIC normally also sends to the printer following each LPRINT. This can be used to string several printobjects together on a single print line. Example: A=12345 LPRINT "The value of A is: "; LPRINT A After execution of these statements the printer would print: The value of A is: 12345 Comments: Note that if the printer is not "online" that DOS will issue a message to "Abort, Retry, or Ignore". This could overwrite a portion of the program display, unless not planned for. Note also, that some printers do not begin printing until they receive a carriage return/line feed sequence. Page - 73 LTRIM$ Format: string1=LTRIM$(string2) Description: This statement will remove all leading spaces from string2 and store the result in string1. Example: A$=" XYZ" A$=LTRIM$(A$) After execution of these statements, the variable A$ will contain the string "XYZ" with no leading spaces. See also: RTRIM$ MID$ Format: string1 = MID$(string2,integer1,integer2) Description: This statement is used to extract a substring from string2 beginning at position integer1 within string2 and continuing for integer2 bytes. This value is then stored in string1. Example: A$="THE QUICK BROWN FOX" B$=MID$(A$,1,4) C$=MID$(A$,11,9) D$=B$ + C$ After execution of these statements, the contents of A$ will be unchanged. The contents of B$ will be "THE ". The contents of C$ will be "BROWN FOX", and the contents of D$ will be "THE BROWN FOX". See also: LEFT$, RIGHT$ Page - 74 MKDIR Format: MKDIR string1 Description: This statement is used to create a new DOS directory. Specify the directory to create in string1. If ASIC is unable to create the directory, it will set the System ERROR variable. A list of ERROR codes may be found is the Error Messages Chapter of the ASIC Manual. Example: MKDIR "WORK" IF ERROR = 0 THEN NOERROR: This code would create a directory called "WORK" under the current directory of the current drive. Example 2: MKDIR "C:\WORK" This code would create a directory called "WORK" under the root directory of drive "C". See also: CHDIR,RMDIR MOD Format: integer1 = integer2 MOD integer3 Description: This statement will perform modulo division of integer2 by integer3 and store the remainder (instead of the quotient) in integer1. Example: A = 8 B = 5 C = A MOD B After execution of these statements, variable "C" will contain the value "3" which is the remainder of the division of 8 by 5. Page - 75 NAME Format: NAME string1 AS string2 Description: This statement will allow you to rename a file. String1 should contain the current file name, and string2 should contain the new name for the file. If ASIC is unable to rename the file, it will set the System ERROR variable. A list of ERROR codes is contained in the Error Messages Chapter of the ASIC Manual. Example: NAME "olddata.txt" AS "newdata.txt" IF ERROR = 0 THEN SUCCESS: After execution of these statements, file "olddata.txt" will have been renamed to "newdata.txt" Comments: You cannot rename a file to a new disk drive. OPEN Format: OPEN string1, integer1, string2 Description: This statement is used to open a file for input or output. Up to three files may be open concurrently, these are known as file 1, 2, or 3. You must specify with integer1 which file number you wish to open this file as. Integer1 may only be a constant. The file mode is specified in string1. The valid values are "I" for INPUT, "O" for OUTPUT, "A" for APPEND, and "R" for RANDOM INPUT/OUTPUT. The file name is specified with string2. Any errors returned from DOS on the OPEN call will be returned in the system variable "ERROR". Example: OPEN "I",3,"INFILE" IF ERROR > 0 THEN PROCESSERROR: OPEN "O",1,"A:\NEWFILE.DAT" IF ERROR > 0 THEN PROCESSERROR: In this example, two files are opened. File "INFILE" from the current disk drive and directory will be opened as file number 3 for input. The file "A:\NEWFILE.DAT" will be opened for output as file number 1. Note that if "A:\NEWFILE.DAT" previously existed, it contents will be destroyed in preparation for writing. See also: CLOSE, FILEPOS, INPUT#, PRINT# Page - 76 OPENCOM Format: OPENCOM(integer1,integer2,integer3,integer4,integer5) Description: This statement is used to initialize the serial port. Integer1 is used to specify the baud rate. Integer2 specifies parity. Integer3 specifies stop bits. Integer4 specifies bytesize, and Integer5 identifies which port to open (see the tables below). OPENCOM does not check the validity of the values you give it. (integer1) (integer2) BAUD RATE PARITY ------+----------- ------+------------ VALUE | DESCRIPTION VALUE | DESCRIPTION 0 | 110 baud 0 | No Parity 1 | 150 baud 1 | Odd Parity 2 | 300 baud 3 | Even Parity 3 | 600 baud 4 | 1200 baud (integer3) 5 | 2400 baud STOP BITS 6 | 4800 baud ------+------------ 7 | 9600 baud VALUE | DESCRIPTION 0 | One Stop Bit 1 | Two Stop Bits (integer4) (integer5) BYTE SIZE COM PORT ------+------------ ------+------------ VALUE | DESCRIPTION VALUE | DESCRIPTION 2 | 7 Bits 0 | Com1 3 | 8 Bits 1 | Com2 Example: OPENCOM(2,0,0,3,0) This statement would open COM1 at 300 baud, No parity, 1 Stop bit, 8 bit bytesize. See also: COMSTAT,RECEIVE,SEND Page - 77 OUT Format: OUT (integer1,integer2) Description: This statement writes a byte to a port. Integer1 should contain the port to write to. Integer2 should contain an integer value in the range of 0-255 to be written to the port. Example: OUT 512,0 The above statement would send a byte with the binary value of "0" to port number 512. See also: INP PEEK Format: integer1 = PEEK (integer2) Description: This statement is used to examine actual memory location values directly. By default, the ASIC DS address is assumed. However, this may be overridden with the use of the DEFSEG command. The value of the byte at address integer2 is stored in integer1. Example: DEFSEG = &hexB800 A = PEEK (0) The above statements will retrieve the first byte of video memory for a CGA/EGA/VGA card and store it in variable "A". Comments: Since the Intel 8088 architecture is segmented in 64k segments, integer2 is limited to the range of 0-65535. See also: DEFSEG, POKE Page - 78 POINT Format: integer1 = POINT (integer2,integer3) Description: This statement is used to determine the color of a given pixel in medium and high resolution graphics modes. The row to test is specified with integer2, the column with integer3. The color of the pixel is stored in integer1. Example: PCOLOR = POINT (10,20) After execution of this statement, PCOLOR will contain the color of the pixel in row 10 column 20. Comments: No range checking is performed on row and column. If the specified row or column is outside the valid range for the given graphics mode, the results are unpredictable. See also: PSET, PRESET, SCREEN Page - 79 POKE Format: POKE integer1, integer2 Description: This instruction is used store the byte value integer2 at the memory address specified by integer1. By default, ASIC uses its default data segment address, however, this may be overridden with the DEFSEG statement. Example: DEFSEG = &hexB800 POKE 0,1 The above statements will store a byte with the binary value of "1" in the first byte of video memory for a CGA/EGA/VGA card. Comments: This statement is NOT RECOMMENDED FOR BEGINNERS. Directly overwriting memory locations can be disastrous, unless you know what is stored at that address. This can cause program "hangs", system crashes, etc. Since the Intel 8088 architecture is segmented in 64k segments, integer2 is limited to the range of 0-65535. See also: DEFSEG, PEEK POS Format: integer1 = POS (integer2) Description: This statement finds the column number of the cursor and stores it in integer1. integer2 is a dummy argument included only because a dummy argument is required in BASICA/GWBASIC. Example: A = POS(0) After this statement executes, A will contain the column number of the cursor. See also: CSRLIN Page - 80 PRESET Format: PRESET (integer1,integer2) Description: This statement is used to set the color of a pixel to the background color. The row of the pixel is specified in integer1, and the column is specified in integer2. This statement only works in graphics modes. Example: PRESET (10,20) The pixel at row 10 column 20 would be set to the background color. See also: PSET, SCREEN, POINT PRINT Format: PRINT [printobject1 [;]] Description: This statement is used to print to the screen. Printing begins at the current cursor location. Printobject1 is defined as any valid ASIC data type: integer constant, integer variable, string constant, string variable, and arrays. The semicolon is optional and is used to tell ASIC if you want a carriage return/line feed issued. A semicolon at the end of a PRINT statement will suppress the carriage return/line feed ASIC normally issues. If no operands are supplied, ASIC will simply issue a carriage return and line feed. Example: A=1000 PRINT "A="; PRINT A PRINT PRINT "DONE!" After execution of these statements your screen would display: A= 1000 DONE! See also: COLOR, SCREEN, LOCATE Page - 81 PRINT# Format: PRINT# constant1, printobject1 [NONULL] Description: This statement is used to write integers and strings to disk. Constant1 identifies the file number that the file was opened as. This must be a constant with a value of 1, 2 or 3. The file must have been previously opened with the OPEN command. If printobject1 is a string, you can also add the optional argument "NONULL", which will cause ASIC to suppress the trailing NULL character it would normally write to disk. DOS errors are returned in the system variable "ERROR". A list of these error codes may be found in the error messages section of the ASIC Manual. Also, refer to the technical details section of the ASIC Manual for more information on the format in which ASIC writes the data to disk. Example: PRINT# 1, "HELLO" IF ERROR = 255 THEN DISKFULL: PRINT# 1, "WORLD" IF ERROR = 255 THEN DISKFULL: After successful execution of the print statements the file identified by file number 1 would contain "HELLO0WORLD0" . Note that the "0" following HELLO and WORLD in our example represents the ASCII null character. Strings in ASIC are always internally terminated with ASCII null characters. By default, these nulls are also written to disk. PRINT# 2, "HELLO" NONULL In this example, the string "HELLO" would be written to file #2, and no trailing NULL will be written to disk. PRINT #3, 1234 In this example, the number "1234" would be written to file #3 as two bytes in Intel binary format (the file would contain the two hexadecimal bytes: D2 04). Page - 82 PRINT# (Continued) Comments: Note that while ASIC doesn't generate carriage returns and line feeds for you as it does with the PRINT command, you can write these characters to disk as follows: A$=CHR$(13) B$=CHR$(10) A$ = A$ + B$ PRINT #1, A$ You might be wondering about the purpose of the NONULL option. ASIC normally writes trailing NULLs with strings. This is desirable if you plan to read the file exclusively with other ASIC programs. However, sometimes you may want to write a string for use by another program. In this case, the NULL character sometimes confuses the other program. Specifying the NONULL option will cause ASIC to suppress the offending NULL character. What happens if you read a string that is terminated by a Carriage Return/Line Feed Sequence (such as GWBASIC/BASICA produces)? In this instance, specify the CRLF option on the INPUT# statement. Then ASIC will read the string until it finds a CR/LF or until it reads 80 characters, whichever comes first. See also: OPEN, CLOSE, INPUT#, FILEPOS Page - 83 PSET Format: PSET (integer1,integer2),integer3 Description: This statement is used to set a pixel to a specified color in graphics modes. The row is specified in integer1, the column in integer2, and the color in integer3. Note that no range checking is performed on integer1 or integer2. A row or column specified outside the range allowed by the graphics mode in use can result in unpredictable results. Example: PSET (10,20),1 In this example the pixel defined at row 10 and column 20 will be set to color 1. See also: PRESET, SCREEN, POINT RANDOMIZE Format: RANDOMIZE Description: This statement will cause the seed for the random number generator to be reseeded using the system timer. This statement should always precede the first RND statement in your program, unless you want the same sequence of random numbers generated. Example: RANDOMIZE The above statement would insure that each time your program runs, any subsequent RND numbers generated would be different. See also: RND Page - 84 READ Format: READ variable1 Description: This statement reads a constant from DATA statements into a variable. Variable1 is either a string or integer type variable. Example: DATA 7,"CARGO" READ A READ B$ After execution of these statements, "A" will contain 7, and B$ will contain "CARGO". Comments: ASIC does not check to see that the data type on the READ statement matches the data type on the DATA statement. It is up to the programmer to insure that the types match. The above example is correct. The DATA statement contains an integer, then a string. This is the same sequence in which the DATA is READ (ie, integer, then string). In the above example, if the read statements were reversed, the contents of A and B$ are undefined. Also note that ASIC does not check to see that you don't read past the end of the DATA you specified. In the above example, if you had a third READ statement that contained "READ C$", then C$ would contain random garbage, since you read three values, but only provided data for two. See also: DATA,RESTORE Page - 85 RECEIVE Format: variable1 = RECEIVE(integer2) Description: This statement will read a byte from the specified serial port. Integer2 identifies which port to read (0=COM1, and 1=COM2). The byte read is stored in variable1 (which may be an integer or string type variable). Before executing this statement you should first check to see if there is data waiting to be read. Executing this statement when data is not waiting can cause your PC to "hang" until data is received at the hardware serial port. The example below illustrates how to determine if data is waiting to be received. Example: OPENCOM(2,0,0,3,0) PORTSTAT = COMSTAT(0) DATAREADY = ZBIT(8,PORTSTAT) IF DATAREADY = 0 THEN NODATAWAITING: A$=RECEIVE(0) These statements do the following. The first retrieves the status of COM1 to the variable PORTSTAT. The second checks to see if bit 8 is on, DATAREADY will contain 1 if so, otherwise it will contain 0. Since Bit 8 is used to determine if data is waiting to be received from the port, if DATAREADY NOT = 0 then the program will RECEIVE data from the port to variable "A$". Comments: Variable1 can be either a string or integer type variable. However, if variable1 is a string, bear in mind that you cannot directly receive a NULL (ASCII Code 0), since NULL is used to delimit the end of a string in ASIC. However, if in the above example data was waiting at the port but A$ contained "" after the receive, you would know that the character received was a NULL. This is not a problem if variable1 is an integer variable. See also: OPENCOM,SEND,COMSTAT Page - 86 REM Format: REM free form comments Description: This statement is used to insert comments into your program. Everything following REM is treated by ASIC as a comment. Example: REM The compiler will ignore this line RESTORE Format: RESTORE Description: This statement allows you to READ data from DATA statements after you have already READ it once. Example: DATA 0 READ A RESTORE READ B In this example, "READ A" causes variable "A" to be set to 0. Now, the DATA statement is "used up". There is no more data left on it to be read. The RESTORE resets the DATA so that the next statement "READ B" will result in "B" being set to 0. If the RESTORE was not done, the contents of B would be undefined. See also: READ, DATA Page - 87 RETURN Format: RETURN Description: Used to return from a GOSUB call. Example: GOSUB PRINTIT: END PRINTIT: PRINT "IT" RETURN In the above example, the word "IT" will be printed on the screen. The RETURN statement causes program execution to resume on the statement following the corresponding GOSUB statement. In this example, control will be returned to the END statement. Comments: Executing a RETURN statement without having first executed a GOSUB statement could cause unpredictable results. See also: GOSUB RIGHT$ Format: string1 = RIGHT$(string2,integer1) Description: This statement will copy the rightmost integer1 characters from string2 to string1. Example: A$=RIGHT$("RED RIDING HOOD",4) After the execution of the above statement, the variable A$ will contain the string "HOOD". See also: MID$, LEFT$ Page - 88 RMDIR Format: RMDIR string1 Description: This statement will delete an empty directory from disk. String1 should contain the name of the directory to delete. If ASIC is unable to delete the directory, it will set the System ERROR variable. A list of ERROR codes is listed in the Error Messages Chapter of the ASIC Manual. Example: RMDIR "C:\WORK\TEST" IF ERROR = 0 THEN SUCCESS: After execution of this code, the directory TEST under directory WORK will be deleted (if it had no files or subdirectories in it, and if it is not the current directory for drive "C"). See also: MKDIR,CHDIR Page - 89 RND Format: integer1 = RND (integer2) Description: This statement will return an integer number in the range of 0 through 32767 for normal integers, and in the range of 0 to 2,147,483,647 for long integers. This random number will be stored in integer1. Integer2 is a dummy argument and can be any valid integer value. Example 1: A& = RND(0) After execution of this statement "A" will contain a number between 0 and 2,147,483,647 inclusive. Example 2: RANDOMIZE DIEROLL=RND(0) DIEROLL=DIEROLL MOD 6 DIEROLL=DIEROLL+1 PRINT "YOU ROLLED A";DIEROLL The above example demonstrates how to generate a number in a given range. In this case, the range will be 1-6, which would be suitable for simulating the roll of a die. The above example will generate the simulated die roll, and print the result. Comments: In BASICA/GWBASIC, RND always returns a value between 1 and 0. Page - 90 RTRIM$ Format: string1=RTRIM$(string2) Description: This statement will remove all trailing spaces from string2 and store the resulting string in string1. Example: A$=RTRIM$("XYZ ") After the execution of this statement, the variable "A$" will contain "XYZ". See also: LTRIM$ Page - 91 RUN Format: RUN string1 Description: This function can be used to load and execute other programs compiled with ASIC or another compiler. String1 represents the name of the program to execute. If an error occurs when ASIC attempts to RUN the program, it will set the system ERROR variable to 255. Otherwise, the ERROR variable will be set to the value of the return code of the called program (which is 0 unless the called program specifies otherwise). Example: RUN "OTHER.COM" Comments: String1 must contain the FULL pathname of the program (ie,"\directory\progname.COM") only if the program is NOT in the current directory. You must include the file extension on the file name (for example, use "MYPROG.COM" instead of just "MYPROG", or use "MYPROG.EXE" instead of "MYPROG"). At this time, RUN and CALL are functionally equivalent, with one exception. RUN does not accept program arguments, but CALL does. CAUTION: You may use the debugger with programs which contain "CALL" or "RUN" statements. However, the programs you call should not themselves contain debugging code. For example, if A.ASI calls B.ASI, then make sure you compile B.ASI with the "Debugging Code" option OFF before you try to debug program A.ASI. Failure to do so will cause the debugger to behave erratically. This also applies to programs you write using other compilers, since they also use the same interrupt that ASIC uses (INT 3) for debugging purposes. See also: CALL Page - 92 SCREEN Format: SCREEN integer1 Description: This statement will transfer the computer between text mode and graphics modes. Integer1 must be an integer constant with a value of 0, 1, 2, 7, 9, or 13. These modes are described in the table below. The "Mode" column identifies the value of integer1 to specify on the SCREEN command to select that graphics mode. The "Graphics Resolution" column has three numbers. The first identifies the number of rows of pixels supported in this mode. The second number identifies the number of columns. The third number identifies the number of colors which may displayed on screen at one time. The numbers in the "Text Resolution" column tell you how many rows, columns and colors you may display on the screen when displaying text. The adapters column identifies the type of graphics adapter required to use this mode. Mode Graphics Resolution Text Resolution Adapters ----- ------------------- --------------- ------- 0 None 25 x 80 x 16 Any Adapter 1 200 x 320 x 4 25 x 40 x 4 CGA/EGA/VGA 2 200 x 640 x 2 25 x 80 x 2 CGA/EGA/VGA 7 200 x 320 x 16 25 x 40 x 16 EGA/VGA 9 350 x 640 x 16 25 x 80 x 16 EGA/VGA 13 200 x 320 x 256 25 x 40 x 16 VGA Example: SCREEN 13 After execution of this statement, the PC will be in Graphics Mode 13 which will allow you to display 200 rows by 320 columns of pixels in 256 different colors. Up to 25 rows and 80 columns of text can be displayed in up to 256 colors. And finally, mode 13 requires a VGA Graphics Card. Comments: Any program which uses the SCREEN command should issue a "SCREEN 0" command before terminating. Otherwise, the screen will not be reset properly when you return to DOS. See also: PSET, PRESET, POINT, ZMODE Page - 93 SEND Format: SEND (data1,integer2) Description: This statement is used to send one character to a serial port. The port should initialized with OPENCOM prior to using this statement. Data1 may be any valid data type (integer or string, variable or constant) and it should contain the character to be sent to the port. Integer2 identifies which COM port to send to (0=COM1, 1=COM2). Example: OPENCOM(2,0,0,3,0) SEND ("X",0) The above code will open COM1 at 300baud, 1 stop bit, 8bit character size, with no parity. It will then send the character "X" to COM1. See also: RECEIVE,COMSTAT,OPENCOM SOUND Format: SOUND integer1,integer2 Description: This statement will generate a sound on your computer speaker with a frequency of integer1, and a duration of integer2. Frequency should be in the range of 0 to 32767. ASIC, however, only checks to see that it is non-negative. Example: SOUND 400,20 Execution of the above statement will produce a short beep. Comments: ASIC "frequencies" values go from high to low. That is, a frequency of 0 is the highest, and 32767 is the lowest. Page - 94 SPACE$ Format: string1=SPACE$(integer1) Description: This statement will return a string containing integer1 ASCII space characters. Example: A$=SPACE$(10) B$="<"+A$ B$=B$+">" After execution of these statements, variable "B$" will contain the string "< >". See also: STRING$ STR$ Format: string1 = STR$ (integer1) Description: This statement will convert integer1 to a string format and store the string format in string1. Example: A=1234 A$ = STR$(A) After execution of these statements, A$ would contain the string "1234". See also: VAL Page - 95 STRING$ Format: string1=STRING$(integer1,integer2) <--Format 1 string1=STRING$(integer1,string2) <--Format 2 Description: This statement will return a string containing integer1 characters of ASCII value integer2 (Format1). If format 2 is used, this statement will create a string containing integer1 characters. Each of these characters will be the same as the first character of string2. Example 1: A$=STRING$(8,111) After execution of these statements, variable "A$" will contain the string "oooooooo". Example 2: A$=STRING$(5,"xyz") After execution of these statements, variable "A$" will contain the string "xxxxx". See also: SPACE$ Page - 96 TIME$ Format: string1 = TIME$ Description: This statement will retrieve the current time from the PC's system clock. The time will be retrieved and stored in String1, in the format: "HH.MM.SS". Example: CURTIME$=TIME$ PRINT CURTIME$ After execution of the above statements the current time (as per the PC's internal clock) will be displayed on the screen. Comments: Note: if the time printed is wrong, you have probably not set the system clock. Most older XTs and PCs do not have a battery to preserve the DATE and TIME in the system clock, so you have to set them each time you power up the PC. Most ATs and newer PCs have a battery backup, so that the date is preserved for you. Unlike GWBASIC/BASICA, you cannot set the system time with TIME$, however, you can set the system time from DOS by typing TIME. See also: DATE$, TIMER Page - 97 TIMER Format: integer1 = TIMER Description: This statement will retrieve a timer count from the PCs hardware circuitry. The timer count will be placed in integer1. The timer count is in "clock ticks". A "clock tick" occurs in the PC approximately 18.2 times per second. The PC is continually incrementing this clock counter. This statement can be used to time the duration of events. Example: CLS PRINT "PRESS A KEY" STARTCNT&=TIMER LOOP:X$=INKEY$ IF X$="" THEN LOOP: ENDCNT&=TIMER ELAPSED&=ENDCNT&-STARTCNT& ELAPSED&=ABS(ELAPSED&) ELAPSED&=ELAPSED&/18 PRINT "IT TOOK YOU APPROXIMATELY"; PRINT ELAPSED& PRINT " SECONDS TO PRESS A KEY" The above code fragment will time how long you wait to press a key in seconds. You could modify it easily to display in clock ticks, which would provide much more accuracy, if you deleted the statement which divides the ELAPSED count by 18. Comments: Note that it is necessary to use the absolute value of ELAPSED& since the clock counts is stored as unsigned integers. ASIC integers, on the other hand, are signed. If integer1 is a long integer variable, then TIMER retrieves the full PC timer value. However, if a normal integer variable is specified as integer1, then ASIC retrieves the least 16 significant bits from the PC timer. See also: DATE$,TIME$ Page - 98 UCASE$ Format: string1=UCASE$(string2) Description: This statement will convert all lowercase letters in string2 to uppercase, and store the resulting string in string1. Example: A$=UCASE$("123 Main St, USA") After execution of this statement, the variable "A$" will contain the string "123 MAIN ST, USA". See also: LCASE$ VAL Format: integer1 = VAL (string1) Description: This statement will attempt to convert string1 into an integer value, and it will store the result in integer1. Example: A$ = "12345" A = VAL (A$) After execution of these statements, variable "A" would contain the value 12345. See also: STR$ Page - 99 VARPTR Format: integer1 = VARPTR (variable1) Description: This statement will return the address of a variable variable1 and store it in integer1. This may be used to peek and poke values directly into a variable. Example: A$ = "XYZ" B = VARPTR(A$) C = PEEK (B) PRINT C After execution of these statements the screen would display the number 88 which is the number for the ASCII character "X". See also: PEEK, POKE WHILE/WEND Format: WHILE condition WEND Description: This statement will execute those statements which are between the WHILE and the WEND statements as long as the "condition" is true. The operand "condition" is one of the following: integer1 > integer2 string1 > string2 integer1 = integer2 string1 = string2 integer1 < integer2 string1 < string2 Example: PRINT "PRESS A KEY TO CONTINUE" A$="" WHILE A$="" A$=INKEY$ WEND In this example, the program will pause until the user presses a key. WHILE statements may be nested 25 levels deep. Page - 100 WIDTH Format: WIDTH integer1 Description: This statement will set the screen to 40 column text or 80 column text mode only. The only two valid values for integer1 are thus 40 and 80. In ASIC, WIDTH 80 is equivalent to executing SCREEN 0. Also, WIDTH 40 is equivalent to executing SCREEN 1. If you use WIDTH 40, you should always reset the screen back to WIDTH 80 before terminating your program with END. Otherwise, your PC will be left in 40 column mode. Example: WIDTH 40 The above statement would put the PC in 40 column mode. ZBIT Format: integer1 = ZBIT(integer2,integer3) Description: This statement is used to determine if a single "bit" in an integer variable is set to "1". Integer2 represents the bit to be tested. It should be in the range 0 to 15. Integer3 represents the integer variable or constant to be tested. The result of the test is returned to integer1. If the bit was set, integer1 will be set to "1", otherwise, integer1 will be set to "0". Example: GAMEPORT = INP(513) TRIGGER = ZBIT(4,GAMEPORT) IF TRIGGER = 1 THEN TRIGGERPRESSED: In this example, the joystick port is read, and its status is placed in the variable "GAMEPORT". The bit which represents the trigger for joystick 1 is then tested using ZBIT. If the trigger bit is set, then the program would transfer to the label "TRIGGERPRESSED:". Note that the above code assumes that a game card is present in the computer. Comments: This statement is an extension over GWBASIC/BASICA, although it is possible to perform similar tests in GWBASIC/BASICA with the boolean AND statement. Page - 101 ZMODE Format: integer = ZMODE Description: This command returns a code which indicates whether a color or monochrome card is active in the system. ZMODE returns a value of 1 when a color card is detected, and a value of 0 for monochrome. Example: A = ZMODE IF A = 1 THEN CONTINUE: PRINT "This program requires a Color Card to Run" END CONTINUE: REM rest of code follows here The above code fragment will check for a color card, if not found the program will terminate with an appropriate message. Otherwise the program will continue. Comments: This statement is an extension over BASICA/GWBASIC. Page - 102 A S I C Chapter 8 Compatibility with GWBASIC/BASICA In general, although ASIC does not support all options on every BASIC statement, those it does support work like they do in BASICA/GWBASIC. The known exceptions are listed in this chapter. INKEY$ This statement is compatible, however ASIC does provide an extension over GWBASIC/BASICA. If an extended key is pressed (e.g. F1- F10), ASIC returns the scan code for the extended key, and sets a special system variable "EXTENDED" to a value of 1. For non-extended keys, the "EXTENDED" variable will contain 0. FILE HANDLING ASIC provides no EOF statement or ON ERROR statements. Instead, ASIC sets a special system variable when an error occurs during file I/O. This special variable is called "ERROR" and it is set after every file I/O statement (OPEN/INPUT#/PRINT#/CLOSE, etc) to either 0 to indicate no errors, or a non-zero value. If a non-zero value is present, an error has occurred. The specific errors are identified in chapter 10. FILE FORMAT ASIC Files are written with 2/4 bytes per normal/long integer in binary format, instead of string format as in BASICA/GWBASIC. Strings are written as a sequence of ASCII characters terminated by an ASCII null, or optionally with no NULL terminator. PUNCTUATION ASIC permits use of punctuation that it does not require to allow you to enter statements in their familiar GWBASIC/BASICA Formats. For example: A = ABS (B(1)) This statement is valid in both ASIC and in GWBASIC/BASICA. However, ASIC ignores the parenthesis and comma. Thus ASIC will actually accept the following formats as alternatives to the above: A = ABS B 1 A = ABS B 1,,,,,,))))) Page - 103 FOR/NEXT FOR/NEXT loops always fall through the body of the FOR at least one time in ASIC. This does not happen in BASICA/GWBASIC. For more information on this, refer to Chapter 7. RND RND (N) returns a value from 0-32767 for normal integers and 0- 2,147,483,647 for long integers instead of 0 to 1 as in BASICA/GWBASIC. LOCATE/CSRLIN/POS Coordinates are specified in range 0-24 and 0-79 instead of 1-25 and 1-80. PSET/PRESET/POINT Coordinates are specified in row/column order instead of column/row order. BLOAD/BSAVE File formats are not compatible with GWBASIC/BASICA. BLOAD requires offset and the number of bytes to read. OPENCOM/COMSTAT/SEND/RECEIVE These statements provide serial port support in ASIC. In GWBASIC/BASICA this is provided by OPEN/INPUT#/PRINT#. DATE$/TIME$ ASIC allows you to retrieve the system date and time, but will not allow you to set new system date/time values. CALL/RUN These statements perform functions similar to their GWBASIC/BASICA counterparts, but function differently. Refer to the keyword reference for the appropriate keyword for details on their operation. Page - 104 EXTENSIONS OVER BASICA/GWBASIC CODE COMMAND$ INT86 FILEPOS FIND LCASE$ LTRIM$ MOD RTRIM UCASE$ ZBIT ZMODE The statements above are extensions over BASICA/GWBASIC. Page - 105 A S I C Chapter 9 Technical Details/Tips This chapter contains technical information and tips regarding ASIC. COMPILER LIMITS Maximum Source Program Size: Unlimited - Command Line 809 Lines - Integrated Environment Maximum Object Program Size: 64k bytes (.COM Format restriction) Maximum Source Line Length 128 bytes - Command Line 80 bytes - Integrated Environment Compiler Symbol Table Size: 750+ Symbols Maximum Number of Arrays: 25 FOR/NEXT Nesting Depth 25 IF/THEN/ELSE Nesting Depth 25 WHILE/WEND Nesting Depth 25 Compiler Memory Requirements 305k - Command Line 405k - Integrated Environment COMPILER OPERATION ASIC is a single pass compiler written entirely in C (Borland Turbo C Version 2.0). Each source statement is translated directly into machine code. ASIC compiles 100% in memory for maximum speed. The compiler does not require any disk work space. ASIC generates a minimum of error checking code. This is because the ASIC philosophy stresses execution speed. This does place greater responsibility on the programmer to check for out of bounds conditions, etc.. Page - 106 MEMORY OPTIMIZATION ASIC 3.0 provides 32 bit long integers in addition to 16 bit normal integers. This allows you to store much larger numbers, however, nothing in life is free. Long integers will increase the size of the resulting ".COM" file by approximately 475 bytes. If you are not using long integers, be sure to compile with the "Extended Math" Option turned OFF so that ASIC does not include these unneeded bytes in your ".COM" file. Otherwise, ASIC will include the long integer support code in your ".COM" file, even if you never create a single long integer! Note: by default, this option is turned off in both the command line and integrated version of the compiler. Also remember that ASIC's debugging option increases your ".COM" file size. So don't forget to recompile your program with the "Debugging" Option turned off (after you have finished debugging it, of course). Page - 107 DEBUGGER LIMITS Maximum Concurrent Breakpoints 20 Maximum Concurrent Watches 10 Maximum Symbol Length 30 Characters Maximum Symbols Same as Compiler Maximum Source Statements 809 Lines DEBUGGER OPERATION When you select the "Debugging code" compiler option, the ASIC compiler inserts additional machine language instructions into your program. It inserts a single statement at the beginning of your program (specifically, INT 3) which allows it to gain control. When the ASIC editor is loaded, it saves the existing INT 3 vector, and installs the ASIC Debugger as INT 3. In this way, when your program begins executing, the INT 3 statement that ASIC inserted in your program causes a transfer of control to the debugger. Once the debugger gains control, it can set or remove additional breakpoints as needed in your program, plus provide access to the video memory and variable memory locations with the Swap, Watch, Unwatch, and Modify Commands. When you exit the ASIC editor, ASIC deinstalls the debugger from INT 3, and restores the original interrupt 3 vector. The compiler also creates a file with a ".DBG" extension which contains the symbolic information needed by the debugger (ie, variable names and offsets, and source statement offsets). DEBUGGER OVERHEAD Running a program in debugging mode adds a small amount of overhead to your program (both compiled code size, and execution speed). Specifically, the size of the debugging code will be (approximately): CodeSizeIncrease = 1 + LinesOfSourceCode Note that the actual increase will usually be less than the above, since DIM, DATA, REM, and blank source lines do not require debugging code. The reduction in execution speed is very slight in most cases (for you assembly language programmers out there, a single NOP instruction is executed for each source line). Page - 108 STORAGE FORMATS Normal integers are stored in ASIC as two bytes, with the low order byte appearing first (as per Intel conventions). Long integers are stored in ASIC as four bytes, with the least significant word first, followed by the most significant word. Within these two words, the least significant byte appears first followed by the most significant byte. String variables are stored as FIXED 80 character strings terminated by an ASCII null character for a total length of 81 characters. String constants are stored with 1 byte per character in the string followed by a terminating ASCII null character. Each element in an array requires two bytes. (Don't forget arrays have an element zero (ie DIM A(2) is comprised of A(0), A(1), and A(2)). Examples: Item Data Type Storage Requirements A Integer Variable 2 bytes 17 Integer Constant 2 bytes A& Long Integer Variable 4 bytes 55555& Long Integer Constant 4 bytes A$ String Variable 81 bytes "ABC" String Constant 4 bytes "A" String Constant 2 bytes DIM A(10) Integer Array 22 bytes DIM A(1) Integer Array 4 bytes DIM A&(10) Long Integer Array 44 bytes As you can see, string variables are expensive in terms of storage space. Since string constants are stored at actual length +1, It is MUCH more efficient to store short strings as constants in ASIC in terms of storage space. There is no performance advantage to constants over variables, however. In disk files, strings and integers are written out in the above formats. Note that unlike GWBASIC/BASICA, integers are NOT expanded into strings when written, and conversely, not converted from strings to integers when read. String variables and constants are written out as ASCII strings terminated by a null character (however, the null can be suppressed). Thus, string variables when written to disk, take the same space byte for byte as string constants. The reason behind fixed length string variables was avoidance of string "garbage collection". In addition to slight performance advantages, there is the added benefit of providing a string memory address which never changes. Thus once VARPTR retrieves the address of a variable, you never have to worry about it changing. Page - 109 MEMORY MAP The following describes the structure of the ".COM" file created by ASIC. All addresses are in Hexadecimal. Description Address Range ------------------------------ ------------- Program Segment Prefix (PSP) 0000 - 00FF (Created/Required by DOS) Transfer to Program Code 0100 - 0102 String Conversion Buffer 0103 - 0109 Input Buffer 010A - 015B Screen Width 015C Color/Attribute Byte 015D Screen Graphics Mode 015E Cursor Position 015F - 0160 File Control Table 0161 - 0169 ERROR System Variable 016A - 016B System Subroutine Vectors 016C - 017F EXTENDED System Variable 0180 - 0181 RND Seed 0182 - 0185 Math Work Area 0186 - 018D DEFSEG System Variable 018E - 018F Start DATA Block Pointer 0190 - 0191 Current DATA Block Pointer 0192 - 0193 Reserved for future use 0194 - 0195 System Subroutines 0196+ | | v Data Segment Address Varies | | | v Code Segment Address Varies | | | v ^ | | Program Stack (builds downward) FFFF Page - 110 A S I C Chapter 10 Error Messages This chapter contains compiler messages, run-time error messages, and File I/O Error Codes. COMPILER ERRORS These messages indicate errors in your source program. Those which begin with "** E" indicate "fatal" errors, which prevent ASIC from successfully compiling your program. Warnings begin with "* W" and indicate possible errors and informative messages which will not prevent ASIC from generating an executable ".COM" file. FATAL ERRORS ** E001 ** File Extensions must be either ".ASI" or omitted ASIC requires source programs to have the extension ".ASI". Rename your source file with the DOS "RENAME" command to the name "file.ASI", where "file" is your source program name. Then resubmit the compile. ** E002 ** File Name specified is too long The source file may be identified by a file name up to 124 characters long including disk drive specifiers and sub directory names. Move the source program to a directory which may be specified within this length. ** E003 ** Error Opening File: xxxxxxxx.xxx The file indicated by "xxxxxxxx.xxx" could not be opened by ASIC. This error can be issued when ASIC attempts to read your source file, or when it writes any one of the possible output files (".COM", ".LST", or ".SYM"). If indicated file is your source program name, verify the spelling, and either make sure it is in the same directory as ASIC, or specify the full path name for the file. If the indicated file is an output file, the error is usually a result of a write protect tab on the diskette or insufficient disk space. Page - 111 ** E004 ** DIM Statements must precede all others except REMs In ASIC, DIM statements must appear before all other statement types, except REM statements (or blank lines). ** E005 ** Too many characters in source line Source program lines in ASIC are limited to 120 characters. Change the indicated source line, so that it fits within this limit. ** E006 ** Unmatched Quote ('"') in source line A string constant was found with either no opening or closing quote mark. Quotation marks must be matched in pairs within source lines. ** E007 ** Token in source line > 82 characters long Individual tokens in ASIC are limited to 82 characters in length, regardless of type. A token is a group of letters and/or numbers delimited on either side by a space or math symbol. Example, even though string constants are limited to 80 characters, ASIC considers the "token" to include the quotation marks. In this case, however, ASIC detected a token longer than the longest possible token, the string constant. Check for "tokens" or "words" more than 82 characters long in the indicated source line. ** E008 ** More than 30 tokens in source line Since all ASIC statements require less than 30 tokens, ASIC will flag any statement which contains more than this number. A token is a group of letters and/or numbers delimited on either side by a space or math symbol. ** E009 ** Keyword Unknown: xxxxxxxxx ASIC detected the symbol indicated by "xxxxxxxx" in your source line, but it was not a valid variable name, constant, label, or ASIC Function Name. ** E010 ** Symbol Table Space Exhausted The symbol table is used by ASIC to keep track of your variables, constants and labels. It is also used to hold information used in FOR/NEXT processing, and internal system subroutine generation. Reduce the number of LABELS, VARIABLE NAMES, or CONSTANTS in your program, and recompile. Page - 112 ** E011 ** Symbol Incomplete Reference Space Exhausted This table is a sister table to the Symbol Table, it contains references to LABEL type symbols which have been defined in the symbol table. Try to reduce the number of references made to LABEL symbols within the program and recompile. ** E012 ** No keywords in source line Every ASIC source program line must contain an ASIC keyword (eg. "PRINT", "=", "GOSUB", etc). ** E013 ** Syntax Error The "catch-all" error for ASIC. This error is usually issued when ASIC has identified an error in the parameters for an ASIC keyword. The best way to find this error is to refer to the entry in the Keyword Reference (chapter 7) for that particular keyword. ** E014 ** Undefined Symbol: xxxxxx ASIC detected a LABEL "xxxxxx" which was referenced, but never defined in the program. A label is considered to be defined when it is the first token on the source line. A reference to a label occurs when a label name appears elsewhere in the source statement Example: PRINTIT: PRINT "hello" <---Defined GOTO PRINTIT: <--Referenced ** E015 ** Compiled Code Exceeds 64k-Can't fit in .COM file Your source program is too large to fit in the .COM file format. Eliminate extraneous variables and program statements. Note: REM statements do NOT generate any output code, so elimination of REM statements will not alleviate this problem. ** E016 ** Integer Constant Not in range +32767 to -32767 The above range of numbers is the maximum which can be contained in integer format in ASIC. Reduce the constant so that it falls within the specified range. ** E017 ** Duplicate Label: xxxxxx The indicated label "xxxxxx" was defined more than once in the program. Reduce the multiple definitions to a single definition and then recompile. Page - 113 ** E018 ** Second FOR defined for variable with no intervening NEXT FOR/NEXT Statements cannot be nested with the same variable name. VALID INVALID FOR I=1 TO 10 FOR I=1 TO 10 FOR J=1 TO 20 FOR I=1 TO 20 NEXT J NEXT I NEXT I NEXT I ** E019 ** For/Next Table Space Exhausted An unlimited of FOR/NEXT statements can exist, however, they can be "nested" to a maximum depth of 25. ** E020 ** NEXT without FOR A NEXT statement was found, however it was not preceded in the source program with a matching FOR statement. ** E021 ** FOR without NEXT at Source Line NNNNN The indicated source line NNNNN contains a FOR statement, for which no NEXT statement was ever found. ** E022 ** Invalid Option: x An invalid compile option was specified. Review Chapter 5 for a list of valid compile options. ** E023 ** More than 63000 bytes in Data Segment An ASIC program can be up to 64k bytes in size. Of this total, 63000 bytes can contain program variables and constants, leaving at least 1k for program code. Reduce the number of variables and constants in your program. ** E024 ** Too many arrays defined A single ASIC source program can contain up to 25 arrays. ** E025 ** Re-DIMension of previously DIMensioned variable Only one DIM statement can be specified per array name. Page - 114 ** E026 ** Invalid subscript on Array A subscript was found which is not valid. Either ASIC expected more or less subscripts than were present, or ASIC detected a subscript which was itself an array. Subscripts on arrays may only be non-array variables and/or integer constants. ** E027 ** String Arrays Are Not Supported A DIM statement specified a string variable type. Only integer arrays are supported. ** E028 ** Comfile Buffer - Memory Allocation Failed ASIC attempted to allocate memory for an internal buffer . This memory allocation failed. More memory is required. If you have any TSRs loaded in memory, remove them and try again. ** E029 ** Codeseg Buffer - Memory Allocation Failed. ASIC attempted to allocate memory for an internal buffer. This memory allocation failed. More memory is required. If you have any TSRs are loaded in memory, remove them and try again. ** E030 ** Code Segment Memory Exhausted ASIC will attempt to allocate 64k of memory to use a work space to hold the code generated by your program statements. This message indicates that the amount of memory it was able to allocate was not sufficient to hold the code generated by the program you are trying to compile. ** E031 ** Data Segment Memory Exhausted ASIC will attempt to allocate 64k of memory to use a work space to hold the data segment for your program. This message indicates that the amount of memory it was able to allocate was not sufficient to hold the data generated by the program you are trying to compile. ** E032 ** Insufficient Memory to Run ASIC You don't have enough memory to run ASIC. If you have any TSRs loaded, try removing them and re-compiling. ** E033 ** Edit Buffer Memory Allocation Failed ASIC attempted to allocate memory for the edit buffer in the integrated environment, but was unable to. If you have any TSRs loaded, remove them from memory, and try again. Page - 115 ** E034 ** DATA Statements Must Precede All Except DIMs or REMs If you wish to use the DATA statement in ASIC, you must place them all at the beginning of your program following any DIM and/or REM statements (or blank lines). ** E035 ** Requires 32 Bit Math--Recompile W/Math Option The compiler found a statement containing long (32bit) integer variables or constants. You must compile with the Extended Math Option turned on to be able to use long integer math. Turn on the "Extended Math" Option from the Compile Menu in the ASIC Integrated Environment, and recompile the program. If you are compiling from the MS DOS command line, recompile using switch "E". ** E036 ** Error Allocating Debugger Screen Memory ASIC was unable to allocate memory to save the screen output from your programs when you run your program in debugging mode in the ASIC integrated environment. You could try removing some TSRs from your AUTOEXEC.BAT file. Then try running ASIC again. ** E037 ** IF Statements Nested Deeper Than 25 Levels An unlimited number of block IF statements may be used in your program, however, they may be nested to a maximum depth of 25 levels. See the IF statement documentation in Chapter 7 for more information. ** E038 ** ELSE Statement Without Preceding IF Statement. ASIC found an ELSE statement but did not find a preceding block IF statement. See the IF Statement documentation in Chapter 7 for more information. ** E039 ** ENDIF Statement Without Preceding IF Statement. ASIC found an ENDIF statement with no preceding matching IF statement. See the IF statement documentation in Chapter 7 for more information. ** E040 ** Block IF Statement Without Matching ENDIF Statement. When using the block IF format of the IF statement, you must always specify a matching ENDIF statement. See the IF Statement documentation in Chapter 7 for more information. Page - 116 ** E041 ** WHILE Statements Nested Deeper Than 25 Levels An unlimited number of WHILE statements may be used in your program, however, they may be nested to a maximum depth of 25 levels. See the WHILE statement in Chapter 7 for more information. ** E042 ** WEND Statement Without Preceding WHILE Statement ASIC found a WEND statement with no preceding matching WHILE statement. See the WHILE statement documentation in Chapter 7 for more information. ** E043 ** WHILE Statement Without Matching WEND Statement Each WHILE statement must be followed by a matching WEND statement. See the WHILE statement documentation in Chapter 7 for more information. Page - 117 NON-FATAL WARNINGS * W001 * Last Statement Not END -- END supplied Warning only. ASIC expects the last statement of a program to be an END statement. If it does not find one, it generates one for you. * W002 * Printer Not Ready - 'P' Option Ignored You selected the "Printer" option, but ASIC was not able to access the printer. Make sure the printer is online before compiling with the 'P' option. * W004 * Edit Buffer Full--File Truncated While loading a file, the edit buffer filled before ASIC reached end-of-file. The file is truncated in memory. IF YOU SAVE THE FILE AFTER RECEIVING THIS MESSAGE, PART OF THE FILE WILL BE LOST ON DISK. IT IS RECOMMENDED THAT YOU EITHER EXIT ASIC IMMEDIATELY, OR THAT YOU SAVE THE TRUNCATED FILE UNDER A NEW NAME SO THAT THE ORIGINAL FILE IS NOT DAMAGED. * W005 * Edit Buffer Full ASIC issues this message when the edit buffer is full and you attempt to insert a line. Delete some unnecessary source lines to create space in the edit buffer. * W006 * Source/Dest of Block Copy/Move May Not Overlap You attempted to move or copy a block of lines to a destination line which was within the source block of lines. Execution of this block move/copy would result in an endless series of copies or moves. Move the cursor outside of the highlighted block of lines, and try again. * W007 * Source Program Modified. Recompile? (Y/N) You selected the RUN or TRACE option of ASIC. ASIC has noticed that you have modified the source. You should answer "Y" here to cause ASIC to recompile your program before running it. If you instead answer "N", ASIC will execute the existing copy of the compiled program, which will not contain your latest changes. * W009 * File has been modified. Save File Now? (Y/N) You have told ASIC to exit back to DOS, but the edit buffer has been modified. You should answer "Y" so that ASIC will save your changes back to disk. If you answer "N" here, any changes you have made to your program since the last SAVE command will be lost. Page - 118 * W010 * Too Much Debugging Info-Truncating ASIC could not handle all of the debugging information it found. This error should not occur. * W011 * Variable Not Found During the processing of a Watch, Unwatch, or Modify Command, you specified a variable name which ASIC could not find in the debugging information. Checking your spelling for possible errors. Also, verify that you have compiled your program with the Debugging compiler option turned ON. * W012 * Maximum Number of Variables Are Being Watched You are already "watching" the maximum number of variables that this version of ASIC supports. "Unwatch" one of the variables in the watch window. This will allow you to "Watch" a new one. * W013 * There Are No Variables Being Watched You selected the "Unwatch" command. However, there are no variables in the watch window to "Unwatch". Before this command may be used, you must first have added a variable to the Watch window using the "Watch variable" command. * W014 * Unable to Load/Run Program When ASIC attempted to load and run either the compiler or your program it detected an error. This is due to one of two reasons. First, ASIC could not find the program on disk. If compiling, make sure that the ASICC.EXE file is in the same directory as the ASIC.EXE file, and make that directory current. The second reason that you might get this error is that there may be insufficient memory available on your PC. In this case, you either need to free up more memory (by removing TSRs etc), or you could execute your program or the compiler from the DOS command line. For more information on compiling from the command line, see Chapter 5--Stand-alone Compiler Options. * W015 * Can't Set Breakpoint There--No Code Generated For That Source Line You attempted to set a breakpoint and either 1) You haven't compiled with the Debugging Compiler Option turned on, or 2) You have tried to set a breakpoint on a line which did not generate any object code. Thus, breakpoints cannot be set on REM or DATA statements, for example. If you are sure that you have compiled with the above option turned on, then try setting the breakpoint on another nearby statement. Page - 119 * W018 * Your Program Must Be Running To Use This Function You selected a function which is only operable when you are running a program (which was compiled with the debugging compiler option turned on). After your program terminates, this function is not available. * W019 * Function Unavailable Until You Terminate Your Program You selected a function while your program was running in debugging mode. Before you can execute this function you must either Abort your program, or allow it to Run until normal termination. Both the Run and the Abort Options are available on the "Run" Menu. * W020 * Invalid Debug (.DBG) File Format ASIC attempted to access the symbolic debugging information file created by the compiler for your program. It was able to locate the file, but detected an error in the format while reading it. Make sure that the version number of both the ASIC Integrated Editor and the ASIC Compiler are the same. The version number is displayed on the top line of the editor screen, following the word "ASIC". It is also displayed on the compiler status screen while a compile is executing. * W021 * Maximum Number of Breakpoints Already Set You have attempted to set another breakpoint, but the maximum number that this version of ASIC can support are already in use. Remove one of the existing breakpoints you have set. This will free one up for your use elsewhere. * W022 * Can't Open ASIC.IDX File You requested online help for an ASIC keyword. This function requires a file called "ASIC.IDX" provided with your ASIC package, and ASIC could not find this file in the current disk directory. Copy this file from your ASIC package to the directory in which you are running ASIC and try again. * W023 * Can't Open ASIC.DOC File You requested online help for an ASIC keyword or menu option. This function requires a file called "ASIC.DOC" provided with your ASIC package, and ASIC could not find this file in the current disk directory. Copy this file from your ASIC package to the directory in which you are running ASIC and try again. Page - 120 * W024 * Can't Open ASICM.IDX File You requested online help for an ASIC menu option. This function requires a file called "ASICM.IDX" which was provided with your ASIC package, and ASIC could not find this file in the current disk directory. Copy this file from your ASIC package to the directory in which you are running ASIC and try again. * W025 * No Help Available For Selected Item There is no online help available for the item you selected. The information should be available in the ASIC Manual. * W026 * Unable To Write ASIC.CFG File You told ASIC to save your current Integrated Environment Options. ASIC attempted to do so, but was not able to. Your options were not saved to disk. This is usually caused by one of two things: 1) The disk is full, or 2) The disk is write-protected. If the disk is full, delete some unneeded files and try again. If the disk is write- protected, remove the write-protect tab from the disk and try again. * W027 * Debugger Can't Fully Save User Screen--Insufficient Memory ASIC was not able to allocate enough memory to save the screen output from your program while it was running in debugging mode in the integrated environment. As a result, the screen displays may become garbled. You should normally only see this message when your program is using a high resolution EGA/VGA graphic mode on machines with very low memory, or you have many TSRs installed. Either purchase more memory, go to a lesser graphics mode, remove some TSRs from the AUTOEXEC.BAT file, or run your program outside of the integrated environment. Page - 121 RUN TIME ERRORS Divide Overflow This message indicates that your program attempted to divide by zero. Page - 122 SYSTEM ERROR CODE VALUES After most commands which access the disk, ASIC sets a special "ERROR" variable to indicate success or failure of that command. After you execute one of these commands, you can reference this variable as a regular variable in your program, to determine the outcome of the command(eg. "IF ERROR = 000 THEN OKAY:"). ERROR Codes Set by BLOAD 000 No Error 002 File Not Found 003 Path Not Found or File Doesn't Exist 004 File Not Found 005 File Access Denied 006-255 Read Past End of File ERROR Codes Set by BSAVE 000 No Error 002 File Not Found 004 File Not Found 005 File Access Denied 006-255 Disk Full ERROR Codes Set by CALL 000-254 Return Code from Program (Zero If Not Set by User Program) 255 Error Loading/Running Program ERROR Codes Set by CHDIR 000 No Error 003 Path Not Found ERROR Codes Set by CLOSE 000 No Error 006 Invalid Handle 095 Cannot Close File -- File is not Open ERROR Codes Set by FILEPOS 000 No Error 001 Invalid Function Number 006 Invalid Handle 098 File mode not Random or Append Page - 123 SYSTEM ERROR CODE VALUES (Continued) ERROR Codes Set by FIND 000 No Error 002 File Not Found 018 No More Files Match Search Criteria ERROR Codes Set by GETDIR 000 No Error 015 Invalid Disk Drive Specification ERROR Codes Set by INPUT# 000 No Error 005 Read Access Denied 006 Invalid File Handle 096 Input String Truncated at 80 characters (this error code is not set when you specify NONULL) 098 File Not Open for Input or Random Modes 099 End of File ERROR Codes Set by KILL 000 No Error 002 File Not Found 005 Access Denied ERROR Codes Set by MKDIR 000 No Error 003 Path Not Found 005 Access Denied ERROR Codes Set by NAME 000 No Error 002 File Not Found 003 Path Not Found or File Doesn't Exist 005 Access Denied 017 Not Same Disk Drive ERROR Codes Set by OPEN --- Mode Input 000 No Error 002 File Not Found 004 File Not Found 005 File Access Denied 254 File Number Already in Use Page - 124 SYSTEM ERROR CODE VALUES (Continued) ERROR Codes Set by OPEN --- Mode Output, Append, or Random 000 No Error 001 Invalid Append Function 003 Path Not Found 004 No File Handle Available 005 File Access Denied 006 Invalid Append Handle 254 File Number Already in Use ERROR Codes Set by PRINT# 000 No Error 005 File Access Denied 006 Invalid File Handle 097 File Not Open for Output, Append, or Random Modes 255 Disk Full ERROR Codes Set by RMDIR 000 No Error 003 Path Not Found 005 Access Denied 006 Can't Delete Current Directory 016 Can't Delete Current Directory ERROR Codes Set by RUN 000-254 Return Code from Program (Zero If Not Set by User Program) 255 Error Loading/Running Program Page - 125