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Power LOGO Release 1.1 by Gary Teachout DISTRIBUTION * * * * * * * * * * * * * * * * * * * * * * Copyright 1990 by Gary Teachout This program is freeware, and may be distributed freely. It may be distributed along with other freely distributable software. It may not be sold for profit, or included as part of a commercial software product. Power LOGO should be distributed together with the entire contents of the "PowerLOGO" directory. No donations are required but they would be accepted and appreciated. Contents of the "PowerLOGO" directory: LOGO The Power LOGO interpreter. LOGO-Startup The startup file to initialize LOGO. Users-Guide This doc file. Quick-Ref A categorized list of the Power LOGO primitives. Whats-New Changes since release 1.0. Utilities Some useful LOGO programs, ect. Utilities.doc About the Utilities file. PathMaster (dir) Doc files for the PathMaster file selector by Justin V. McCormick. ILBM.Library A library for loading and saving pictures, by Software Dissidents. This should be placed in the libs directory on your Workbench disk. DISCLAIMER * * * * * * * * * * * * * * * * * * * * * * THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO ITS FITNESS FOR ANY PARTICULAR PURPOSE. This software is experimental and IT HAS DEFECTS, if you do not accept all of the risks and responsibilities of using defective software, then DO NOT USE THIS. POWER LOGO? * * * * * * * * * * * * * * * * * * * * * * Power LOGO is an experimental dialect of the LOGO programming language, with a few lisp like features, and a few simplifications. I tried to make few assumptions about how you may want to use this language, wherever possible features are provided as options. User defined procedures are not limited to a fixed number of inputs, they may be defined with required inputs, optional inputs, and local variables. User defined procedures are just variables that contain a special type of list, and are defined using the "make" primitive (Power LOGO has no "to" or "end" primitive). This allows procedures to be processed as data. Syntax is Straight Polish (prefix only), inputs to a procedure follow to the right of the procedure name. There is no infix arithmetic, no special delimiters, and no exceptions in syntax. All LOGO objects (words, lists, list brackets, and parenthesis) must be separated by a space, or by a linefeed. Much of the Amiga graphics capability is supported. Primitives are provided to open custom intuition screens and windows, draw lines, patterned lines, text, flood fills, copy regions, and for turtle graphics. All primitives and keywords are lower case, all names and data defined may be any case. Most other versions of LOGO (and Lisp) promote all text to upper case on input. Demons (high-level interupts) may be programmed to respond to events from the keyboard, menus, left mouse button, and window close gadgets. There is no built-in text editor. LOGO stores programs as ASCII text files, which may be created and modified using any text editor. Or you may type them at the command window. Menus may be attached to any window. Along with menu demons this allows LOGO programs to have friendly user interfaces. You may customize the LOGO user interface by attaching your own menus to the LOGO command window. Properties are just variables that contain a special type of list. Properties give LOGO a data base like capibility. Support for Workbench, and CLI arguments is provided by the "argslist" primitive, but LOGO does nothing with this information, it is up to a program running in LOGO to make use of this capability. The default "LOGO-Startup" file will load any files named as arguments when LOGO is first run. Power LOGO provides many primitives not typicaly found in LOGO. Primitives for arithmetic (frac, log, power...), flow of control (cond, dowhile, whenmenu, while...), words and lists (alphap, items, repitem, represt, restof...), and others. REQUIREMENTS * * * * * * * * * * * * * * * * * * * * * * Power LOGO should run on most Amiga computers, it requires about 250 K bytes, but can use all available memory if needed. To use the "saveimage", and "loadimage" commands, your LIBS: directory must contain the "ILBM.Library" by Software Dissidents. GETTING STARTED * * * * * * * * * * * * * * * * * * * * * * LOGO may be run in the usual way from the WorkBench or the CLI. You may exit LOGO by entering the quit command. If a file called LOGO-Startup is found in the same directory with LOGO it will be loaded to initialize LOGO. This file should contain LOGO code that may be used to configure LOGO the way you like, and to load your own frequently used procedures, and data. LOGO opens a window on the workbench screen as its command input and output window. You may enter and edit LOGO commands with these special keys. Backspace Delete character to the left of the cursor. Cursor Right Move cursor right one space. Cursor Left Move cursor left one space. Cursor Up Move backward through the command history. Cursor Down Move forward through the command history. Control-G Stop program, return to top level. Control-K Delete from cursor to end of line. Control-U Delete from cursor to start of line. Control-X Delete the line. Delete Delete character under the cursor. Return Enter list or instructions. Shift Cursor Right Move cursor to end of line. Shift Cursor Left Move cursor to start of line. The "? " prompt means LOGO is waiting for a command. If the command line contains an open list (an open bracket " [ " without a closing bracket " ] ") you will see the "1 > " prompt allowing you to continue the list on another line. PROGRAMMING * * * * * * * * * * * * * * * * * * * * * * In the Power LOGO programming environment, everything is either a word or a list. Words can be any sequence of characters. Words are separated from each other by blank spaces, to include a space (or a backslash) in a word it must be preceded by a backslash (\). Numbers are just a special type of word. Numbers prefixed with an "@" symbol will be recocnized by some procedures as pointers. Lists can be any sequence of objects, which may be ether words or lists. Lists are identified by enclosing them in brackets "[]". This-is-a-word! [ This is a list! ] Words and lists may be either data or instructions. An instruction is a procedure name followed by any inputs the procedure may require. When LOGO tries to evaluate a word it may treat it in one of three ways, as a literal, as a variable, or as a procedure. Words preceded by a quote (") character (called quoted words) are literal and evaluate as the word itself. For words that happen to be numbers or pointers the quote is not needed. Words preceded by a colon (:) character (called dotted words) refer to the contents (binding) of a variable name. A word by itself (no dots or quote) is evaluated as a procedure (unless it is a number or pointer). ? print 123 123 Here "print" is a procedure, and the number "123" is its input. The "print" procedure simply prints its inputs on next line in the command window. ? print [ This is a list! ] This is a list! In this example the list (everything between the brackets) is the input to the "print" command. ? print "This-is-a-word! This-is-a-word! In this example the quote (") identifies the input as a literal word. The inputs to a procedure need not be literal, they may be the contents of a variable, or the output of another instruction. Instructions may be nested as inputs within other instructions. ? pr * 7 6 42 Here "*" is another procedure "6" and "7" are its inputs. "*" outputs the product of its inputs to pr ("pr" is just an abbreviation for "print") which prints it on the next line. ? make "x 100 ? pr :x 100 In the first line the "make" procedure assigns 100 as the contents of the variable "x". In the second line ":x" refers to the contents of "x". Each procedure has some number of required inputs (zero or more), and some number of optional inputs (zero or more). To include optional inputs the entire instruction must be enclosed in parenthesis. If only the required inputs are used, the parenthesis are not needed. Print requires one input but may have many. ? ( pr "PI "= 3.1415 ) PI = 3.1415 In this instruction "pr" has three inputs. ? ( pr [ And the answer is ] * 4 ( + 1 2 3 ) ) And the answer is 24 This entire line is one instruction where "pr" has two inputs, the first is the list "[ And the answer is ]", the second is the instruction "* 4 ( + 1 2 3 )". This second instruction "*" has two inputs "4" and another instruction "( + 1 2 3 )". Primitives are the procedures that are bult-in to LOGO. You may define your own procedures and add them to LOGO. In Power LOGO a procedure is just a variable that contains a special type of list, and may be defined using the "make" primitive. The first item in a procedure definition list is the word procedure. The second item is a list of lists of names of the inputs and local variables used by the procedure (the names list). The rest of the items in the definition are the instructions executed by the procedure. ? make "hello [ procedure [ ] pr [ Hello World ! ] ] ? hello Hello World ! Because this example procedure uses no inputs or local variables the names list may be empty. The first item of the variable names list is a list of required inputs. The second item is a list of optional inputs or a name to receive a list of optional inputs. The third item is a list of names of local variables. Local variables and unused optional inputs contain the empty list at the start. ? make "hello [ 1 > procedure [ [ ] [ :n ] ] 1 > repeat if numberp :n [ :n ] [ 1 ] [ 2 > pr [ Hello World ! ] ] ] ? hello Hello World ! ? ( hello 3 ) Hello World ! Hello World ! Hello World ! ? ( hello 0 ) This example uses one optional input. See the example files for other forms of names lists. Global, free, and local variables all work as they would in lisp. All variable names in a procedure names list are local within each call to that procedure. They are free variables to all procedures called from within that procedure or at a lower level. A procedure that includes a call to itself is called a recursive procedure. ? make "factorial [ 1 > procedure [ [ :f ] ] 1 > output if < 1 :f [ * :f factorial - :f 1 ] [ :f ] ] ? factorial 5 120 This procedure uses recursion to compute the factorial of its input. A procedure in which the recursive call is the last instruction is called tail recursive. Tail recursion is handled differently by LOGO because the local variables need not be preserved. Two cases are recognized as tail recursion, a recursive call as the input to an "output" command, or a recursive call followed by a "stop" command. ? make "count100 [ 1 > procedure [ [ :x ] ] 1 > pr :x 1 > if < :x 100 [ output count100 + :x 1 ] [ output :x ] ] ? make "count [ 1 > procedure [ [ :x ] ] 1 > pr :x 1 > count + :x 1 1 > stop ] In the second example the "stop" command is never executed, but it is necessary for LOGO to recognize the call to "count" as tail recursion, without it "count" would run out of memory. FILES * * * * * * * * * * * * * * * * * * * * * * Primitives are provided to save and load the contents of variables (including procedures), read and write data, save and load IFF images, attach icons to files, and get a filename through a file requester. The "save" primitive saves the contents of variables to a file as "make" commands. The "load" command executes a text file as if it were typed at the command window except that comments are ignored (a comment is everything from a semicolon ";" to the end of the line). To read or write a data file it must first be opened with "open" (a new file to be writen), or "openold" (an existing file to be read or appended). Each of these outputs a file pointer (a BCPL pointer to an AmigaDOS file handle) which must later be closed using "close". The primitives for reading and writing files accept a file-pointer as input and work much like their command window counterparts. The "saveimage", and "loadimage" primitives copy the contents of a window to or from an IFF ILBM file. For these to work the "ILBM.Library" by Software Dissidents must be in the LIBS: directory. The "filerequest" primitive outputs an AmigaDOS file name selected with the PathMaster file selector by Justin V. McCormick. "filerequest" may be used as input to any procedure that requires a file name. GRAPHICS * * * * * * * * * * * * * * * * * * * * * * Much of the Amiga graphics capability is available in Power LOGO. Primitives are provided to open custom intuition screens and windows, draw lines, patterned lines, text, flood fills, and copy regions. Graphics are rendered into windows which must first be opened with "openwindow". The window graphics primitives require a pointer to a window as an input. Coordinates within windows start with (0,0) in the upper left corner and count pixels to the right and down. TURTLES * * * * * * * * * * * * * * * * * * * * * * Turtles are graphics tools based on reletive movement. You may open many turtles, each is opened onto a window, has its own coordinate system, and has its own sense of location, distance, and direction, as well as its own foreground pen, background pen, draw mode, and line pattern. By default the turtle commands control all active turtles, but may be directed to control specific turtles (active or not). Turtle operations output information about one specified turtle. DEMONS * * * * * * * * * * * * * * * * * * * * * * A demon may be thought of as a process separate from your main program, that keeps testing for a particular kind of event. When the event is detected the demon interupts the main program and runs a special procedure. When the procedure is complete the main program will resume. There are four types of events that may trigger demons, menu selection, left mouse button, key stroke, and window close gadget. For each of these there is an event queue, when the event queue is not empty, the demon procedure will be run. The demon procedure must execute the appropriate get operation to remove the event from the queue, or the demon will run again and again. For a simple example of demons in action load the file Mouse-Paint. For examples of menu demons see the files LOGO-Startup, and Mandelbrot. ERRORS * * * * * * * * * * * * * * * * * * * * * * Errors in syntax, or anything the interpreter does not recognize as valid LOGO instructions, should produce meaningful error messages. Primitives that expect a pointer as input may cause LOGO to crash (guru) if passed a bad pointer. The primitives "repitem", and "represt" destructively change an existing list and must be used carefully. If there is more than one reference to the list all references will be changed. They can also result in circular lists which appear infinite, and may cause LOGO to get stuck in a loop. RECOMMENDED READING * * * * * * * * * * * * * * * * * * * * * * This document file describes the differences between Power LOGO and traditional versions of LOGO, these books will provide more background about LOGO. Two of these books, Computer Science Logo Style volume 1, and Visual Modeling with LOGO, include sections that may be helpful to beginners. There are many books available about programming in LOGO for beginners, however the ones that I have read are not very good, and none are listed here. Computer Science Logo Style Volume 1: Intermediate Programming, 1985. Volume 2: Projects, Styles, amd Techniques, 1986. Volume 3: Advanced Topics, 1987. Brian Harvey MIT Press. These are excellent books for anyone interested in programming, and computer science. Mindstorms: Children, Computers, and Powerful Ideas. Seymour Papert Basic Books, 1980 This book is about education and how computers and programming may be used by children, parents, and teachers. Required reading for parents, and teachers interested in how children can make use of computers. Turtle Geometry: The Computer as a Medium for Exploring Mathematics. Harold Abelson, and Andrea diSessa MIT Press 1981 About turtles as a tool for the study of mathematics, geometry, and topology. Visual Modeling with LOGO: A Structural Approach to Seeing. James Clayson MIT Press, 1988 About using LOGO and turtle graphics for exploring visual ideas and relationships. LOGO PRIMITIVES * * * * * * * * * * * * * * * * * * * * * * Format for decriptions of primitives: NAME INPUTS ( OPTIONAL-INPUTS ) SYNONYM ALTERNATIVE INPUTS INPUT = DESCRIPTION OF INPUT. FUNCTION DESCRIPTION. The Power LOGO primitive set: + number number ( number... ) sum number = Any number. Addition, output the sum of all inputs. - number number ( number... ) difference number = Any number. Subtraction, output first input minus all of the other inputs. * number number ( number... ) product number = Any number. Multiplication, output product of all inputs. / number number ( number... ) quotient number = Any number. Division, output first input divided by each of the other inputs. +- number negate number = Any number. Change sign, output opposite of input. > number number ( number... ) number = Any number. Output true if first input is more than all others. < number number ( number... ) number = Any number. Output true if first input is less than all others. >= number number ( number... ) number = Any number. Output true if first input is more than or equal to all others. <= number number ( number... ) number = Any number. Output true if first input is less than or equal to all others. =0 number ( number... ) number = Any number. Output true if all inputs are equal to zero. <0 number ( number... ) number = Any number. Output true if all inputs are less than zero. >0 number ( number... ) number = Any number. Output true if all inputs are more than zero. abs number number = Any number. Output absolute value number. activelist Output list of pointers to active turtles. alphap word word word = Any word. Output true if words are in alphabetical order. and predicate predicate ( predicate... ) predicate = true or false. Output true if all inputs are true. argslist Output list of startup arguments, the first item in the argslist is the file name of LOGO, the rest are the args from Workbench, or CLI. ascii word word = Any word. Output ASCII number of first character in word. atan tangent tangent = Any number. Inverse tangent, output angle for tangent. back distance ( turtle ... ) bk distance ( turtle-list ) distance = Number, distance in turtle steps. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Move turtles backward distance. buriedp object object = Any word or list. Output true if input is a buried variable name. burylist Output list of names that are buried. bury name ( name... ) name-list ( name-list... ) name = Word, a variable name. name-list = List of names. Hide and protect input variable names (hide from make, erase, namelist, etc.). butfirst object bf object = Any word or list. Output all but the first item of the input object. butlast object bl object = Any word or list. Output all but the last item of the input object. catch label run-list label = Any word. run-list = List of LOGO instructions. Execute run-list, set trap for matching throw. The label "error" may be used to trap errors. cd ( path ) path = An AmigaDOS directory name (word or list). Set the current directory to the specified path, or output the current directory. char ascii ascii = Any number from 1 to 255. Output word containing one ASCII character. clean ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Blank turtles windows. cleartext Blank the command window. closep Output true if window-close queue is not empty. close file ( file... ) file = BCPL pointer to AmigaDOS file handle. Close files. closescreen screen ( screen... ) screen = Pointer to an intuition screen. Close screens. closeturtle turtle ( turtle... ) turtle = Pointer to a turtle. Close turtles. closewindow window ( window... ) window = Pointer to an intuition window. Close windows. conditional conditional-list cond conditional-list = A list: [ predicate-list run-list ... ] predicate-list = A run-list that outputs true or false. run-list = List of LOGO instructions. Execute the run-list following the first true predicate-list. copyrect window X Y window X Y width height window = Pointer to an intuition window. X = Number, pixel x coordinate. Y = Number, pixel y coordinate. width = Number, width of region in pixels. height = Number, height of region in pixels. Copy a rectangular region from window to window. cos angle angle = Number representing an angle. Output cosine of angle. count object object = Any word or list. Output number of items in object. cursor Output position-list of command window text cursor. degrees Interpret angles as degrees. dir ( path ) path = An AmigaDOS directory name (word or list). Output list of contents of the specified path, or the current directory. doscommand command-line command-line = List containning an AmigaDOS command line. Run list as AmigaDOS command (as if typed at the CLI). dot ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Mark one pixel at turtles position. dowhile run-list predicate-list run-list = List of LOGO instructions. predicate-list = A run-list that outputs true or false. Execute run-list while predicate-list is true. downp turtle turtle = Pointer to a turtle. Output true if turtles pen is down. draw window X Y window = Pointer to an intuition window. X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Draw from a windows graphics cursor position to position X Y. emptyp object object = Any word or list. Output true if object is the empty list or word. eqp object object ( object... ) object = Any word or list. Output true if all inputs refer to the same object. equalp object object ( object... ) = object = Any word or list. Output true if objects are identical. erase name ( name... ) name-list ( name-list... ) name = Word, a variable name. name-list = List of names. Remove bindings (contents) of input names that are not buried. Or remove bindings of all input names. error Output list containing the error number, procedure name, primitive name, and the offending input from the most recent error. exor predicate predicate predicate = true or false. Output true if one input is true and one is false. filelist Output list of pointers to all open files. filerequest ( title ) title = Word, title bar text. Output file path name selected from file requester. This is the PathMaster file selector by Justin V. McCormick. first object object = Any word or list. Output first item of object. firstput object object fput object = Any word or list. Output object made by adding first input to beginning of second input. floodol window X Y window = Pointer to an intuition window. Y = Number, pixel x coordinate. Y = Number, pixel y coordinate. Flood fill to outline. forward distance ( turtle ... ) fd distance ( turtle-list ) distance = Number, distance in turtle steps. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Move turtles forward distance. fprint file object ( object... ) file = BCPL pointer to AmigaDOS file handle. object = Any word or list. Print object to file. fprintout file name ( name... ) file name-list ( name-list... ) file = BCPL pointer to AmigaDOS file handle. name = Word, a variable name. name-list = List of names. Print names and their bindings file. frac number number = Any number. Output fractional portion of number. freadbyte file file = BCPL pointer to AmigaDOS file handle. Output one byte number read from file, Output the empty list if end of file. freadlist file file = BCPL pointer to AmigaDOS file handle. Output list read from file (or the empty word if end of file). fshow file object ( object... ) file = BCPL pointer to AmigaDOS file handle. object = Any word or list. Print object to file. ftype file object ( object... ) file = BCPL pointer to AmigaDOS file handle. object = Any word or list. Print object to file. fwritebyte file number ( number... ) file = BCPL pointer to AmigaDOS file handle. number = Any number from 0 to 255. Write one byte numbers to file. getclose Output a pointer to a window from the window close event queue, wait if the event queue is empty. getmenu Output list containing a pointer to the window, the menu number, item number, and subitem number of the next item from the menu event queue, wait if the menu event queue is empty. getmouse Output list containing a pointer to the window, the X position, and Y position where the mouse was when the button was pressed, wait if the mouse event queue is empty. getprop name property gprop name = Word, name of a veriable containing a property list. property = Word, label of an object in a property list. Output specified object from a property list. heading turtle turtle = Pointer to a turtle. Output a turtles heading. home ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Move turtles to position (0,0) set heading to 0. if predicate run-list run-list predicate = true or false. run-list = List of LOGO instructions. If predicate is true execute first run-list, if false execute second run-list. Both run-lists are required, if one case is not used, use the empty list [ ]. int number number = Any number. Output integer portion of number. intuition action pointer ( ?... ) action = A number from 1 to 11, specifing action to be taken. pointer = A pointer to an intuition screen or window. ? = Listed below. Eleven commands in one, to modify screens, windows, and menus. 1 screen X Y X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Move screen (screen = @0 for workbench screen). 2 window X Y X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Move window (window = @0 for command window). 3 window menu item subitem menu, item, subitem = Numbers specifing a menu or item. Off menu (window = @0 for command window). 4 window menu item subitem menu, item, subitem = Numbers specifing a menu or item. On menu (window = @0 for command window). 5 screen Screen to back (screen = @0 for workbench screen). 6 screen Screen to front (screen = @0 for workbench screen). 7 screen showit showit = Number. Show screen title (number <> 0) hide title (number = 0). 8 window width height width = Number, width of window in pixels. height = Number, height of window in pixels. Size window (window = @0 for command window). 9 window MinWidth MinHeight MaxWidth MaxHeight MinWidth \ MinHeight \ MaxWidth / = Numbers, sizes in pixels. MaxHeight / Set window limits (window = @0 for command window). 10 window Window to back (window = @0 for command window). 11 window Window to front (window = @0 for command window). item element object element = Number, index to item. object = Any word or list. Output specified item from object. items first count object first = Number, index to first item. count = Number of items. object = Any word or list. Output specified items from object. keyp Output true if character queue is not empty. last object object = Any word or list. Output last item from object. lastput object object lput object = Any word or list. Output object made by adding first input to end of second input. left angle ( turtle ... ) lt angle ( turtle-list ) angle = Number representing an angle. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Rotate turtle left. linep Output true if command window input line queue is not empty. listp object object = Any word or list. Output true if object is a list. list object object ( object... ) object = Any word or list. Output list containing input objects. load file-name ( file-name... ) file-name = An AmigaDOS file name (word or list). Load file, runs a text file as if it were typed at the keybord. loadimage window file-name window = Pointer to an intuition window. file-name = An AmigaDOS file name (word or list). Load a window from an IFF ILBM file. Requires "ilbm.library" from Dissidents Software. BUG: sometimes loads entire screen. log base number base = Positive number. number = Positive number. Output logarithm of the number to the base. make name object name = Word, a variable name. object = Any word or list. Make object the contents of name (bind object to name). Make is the LOGO variable assignment operator. memberp object object object = Any word or list. Output true if second object contains first object. menup Output true if menu queue is not empty. mousep Output true if mouse-button queue is not empty. mouse window window = Pointer to an intuition window. Output list containing the X position, Y position and button position of the mouse reletive to the window. move window X Y window = Pointer to an intuition window. X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Move a windows graphics cursor to position X Y. namelist Output list of variable names in use. namep object object = Any word or list. Output true if object is a variable name. new Remove bindings of all names (erase), close all files, close all turtles, close all windows, close all screens, clear all menus, clear all demons, flush all input queues, return to top level. not predicate predicate = true or false. Output true if input is false output false if input is true. numberp object object = Any word or list. Output true if object is a number. open file-name file-name = An AmigaDOS file name (word or list). Create or open file to be written, output BCPL pointer to an AmigaDOS file handle. openold file-name file-name = An AmigaDOS file name (word or list). Open existing file to be read or written, output BCPL pointer to an AmigaDOS file handle. openscreen vm ( d t le te w h dp bp ) screen-data-list vm = Number, viewport modes, sum of: 1 = hires 2 = lace 4 = extra half brite d = Number of bit planes. t = List, title bar text. le = Number, left edge. te = Number, top edge. w = Number, width. h = Number, height. dp = Number, detail pen. bp = Number, block pen. screen-data-list = List containing some or all of the above. Default screen-data-list = [ 0 2 [ ] 0 0 320 200 0 1 ] if view modes = hires then default width = 640 if view modes = lace then default height = 400 if view modes = extra half brite then default depth = 6 Open an intuition graphics screen, output pointer to the screen. openturtle window ( mag ar X Y h t ) turtle-data-list window = Pointer to an intuition window. mag = Number, scale or magnification. ar = Number, aspect ratio, pixel width / height. X = Number, pixel x coordinate of home. Y = Number, pixel y coordinate of home. h = Number, heading of home. t = Number, turning direction, >= 0 clockwise, < 0 counterclockwise. turtle-data-list = List containing some or all of the above. Defaults: mag lores 1.8 hires 3.2 This means it takes 200 steps to go from the left edge to the right edge of a full screen. ar lores 0.88 hires 0.44 lores lace 1.76 hires lace 0.88 This makes circles look round and squares look square. X, Y The current center of the window. h 0 Straight up. t 0 Clockwise. Open a turtle, output pointer to the turtle. openwindow screen ( f t le te w h dp bp minw minh maxw maxh ) window-data-list screen = Pointer to an intuition screen, @0 for workbench screen. f = Number, flags, sum of: 1 = drag gadget 2 = depth gadget 4 = close gadget 8 = size gadget 16 = give me zero zero 32 = backdrop 64 = borderless 128 = activate t = List, title bar text. le = Number, left edge. te = Number, top edge. w = Number, width. h = Number, height. dp = Number, detail Pen. bp = Number, block Pen. minw = Number, minimum width. minh = Number, minimum height. maxw = Number, maximum width. maxh = Number, maximum height. window-data-list = List containing some or all of the above. Default window-data-list WorkBench screen: [ @0 3 [ ] 0 0 320 200 0 1 30 30 640 400 ] Default window for custom screen: Backdrop borderless window to fit the screen. Open an intuition graphics window, output pointer to the window. or predicate predicate ( predicate... ) predicate = true or false. Output true if any inputs are true. output object op object = Any word or list. Exit procedure, return object as the procedures output. pd ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Pen down, lower the turtles pen. peek bytes address bytes = Number, one of: 0 32 bit pointer 1 8 bit unsigned integer -1 8 bit signed integer 2 16 bit unsigned integer -2 16 bit signed integer 4 32 bit unsigned integer -4 32 bit signed integer 8 64 bit IEEE double floating point number address = Number, or pointer, a memory address. Output number contained at address. pen window ( type ) window = Pointer to an intuition window (@0 for command window). type = Number, which pen: 0 foreground pen (default) 1 background pen 2 area outline pen Output the windows pen number. poerror Print out error message. pointerp object object = Any word or list. Output true if object is a pointer. poke bytes address number ( number... ) bytes = Number of bytes: 1 8 bit integer 2 16 bit integer 4 32 bit integer or pointer 8 64 bit IEEE double floating point number address = Number, or pointer, a memory address. number = Number, or pointer, limited in size by number of bytes. Write numbers to memory address. power base exponent base = Any number. exponent = Number, if base < 0 then exponent must be an integer. Output base to the power of exponent. precision ( digits ) digits = Number from 0 to 15. Sets or outputs precision used by print, fprint, type, ftype, and text when printing numbers. primitivep object object = Any word or list. Output true if object is a primitive. print object ( object... ) pr object = Any word or list. Print object to command window. printout name ( name... ) po name-list ( name-list... ) name = Word, a variable name. name-list = List of names. Print names and their bindings to command window. procedurep object object = Any word or list. Output true if object is a user defined procedure. psum address number ( number... ) address = Number, or pointer, a memory address. number = Any number. Output pointer equal to sum of address and numbers. pu ( turtle... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Pen up, raise the turtles pen. putprop name property object pprop name = Word, name of a veriable containing a property list. property = Word, label of an object in a property list. object = Any word or list. Place object into a property list. quit Exit LOGO return to WorkBench or CLI. radians Interpret angles as radians. rand Output random fraction from zero to less than one. random range range = Number, positive integer. Output random integer from zero to less than number. readchar rc Output one character word typed at keybord. Reads characters from windows other than the command window. Waits if character event queue is empty. readlist rl Output line typed at keybord as a list. Reads lines from the command window. Waits if line queue is empty. readpixel window X Y window = Pointer to an intuition window. X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Output pen number of pixel at position (X,Y). rectfill window l t r b window = Pointer to an intuition window. l = Number, left edge of rectangle in pixels. t = Number, top edge of rectangle in pixels. r = Number, right edge of rectangle in pixels. b = Number, bottom edge of rectangle in pixels. Fill rectangle from (l,t) to (r,b). recycle ( number ) number = Any number. Without an input, recycles memory and frees any unused blocks. With an input, just recycles memory. remainder number number number = Any number. Output remainder after division. remprop name property name = Word, name of a veriable containing a property list. property = Word, label of an object in a property list. Remove object from a property list. repeat number run-list number = Number, positive integer. run-list = List of LOGO instructions. Execute run-list number of times. repitem item list object item = Number, index into list. list = Any list. object = Any word or list. Replace specified item of list with object. This is similar to "rplaca" in Lisp. WARNING: repitem destructively changes an existing list and you may obtain unexpected results if there is more than one reference to the list. represt item list object item = Number, index into list. list = Any list. object = Any word or list. Replace rest of list after specified item with object. This is similar to "rplacd" in Lisp. WARNING: represt destructively changes an existing list and you may obtain unexpected results if there is more than one reference to the list. restof number object item = Number, index into object. object = Any word or list. Output rest of object following specified item. rgb screen index screen = Pointer to an intuition screen. index = Number, index into the screens color table. Output list containing red, green, and blue value of the screens specified color. right angle ( turtle ... ) rt angle ( turtle-list ) angle = Number representing an angle. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Rotate turtle right. round number number = Any number. Output number rounded to nearest integer. run run-list run-list = List of LOGO instructions. Execute run-list. save file-name name ( name... ) file-name name-list ( name-list... ) file-name = An AmigaDOS file name (word or list). name = Word, a variable name. name-list = List of names. Save variable names and their contents to file. saveicon file-name ( default-tool tool-types ) file-name = An AmigaDOS file name (".info" will be added). default-tool = Word. tool-types = List of up to three words. Attach icon to file. saveimage window file-name window = Pointer to an intuition window. file-name = An AmigaDOS file name (word or list). Save a window to an IFF ILBM file. Requires "ilbm.library" from Dissidents Software. BUG: sometimes saves entire screen. screenlist Output list of pointers to all open screens. seconds Output system clock time in seconds. seedrand ( number ) number = Any number. Re-seed random number generator. seekend file file = BCPL pointer to AmigaDOS file handle. Move to end of file. seekstart file file = BCPL pointer to AmigaDOS file handle. Move to start of file. sentence object object ( object... ) se object = Any word or list. Output list of input objects. Lists in the input to sentence will have their outer brackets removed. "sentence" always creates a new list. setafpt window pattern-list window = Pointer to an intuition window. pattern-list = A list of up to 16 words, each 16 characters long where "x" is an on pixel, any other character is an off pixel. Set area fill pattern. setcursor position position = List of two numbers, X, and Y coordinates. Set command window text cursor position. setdrmode window mode window = Pointer to an intuition window (@0 for command window). mode = Number, sum of: 0 = JAM1 1 = JAM2 2 = COMPLEMENT 4 = INVERSVID Set a windows draw mode. setfont window font-name font-height window = Pointer to an intuition window (@0 for command window). font-name = Word. font-height = Number. Set a windows text font. seth angle ( turtle ... ) angle ( turtle-list ) angle = Number representing an angle. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Set turtles heading. setlinept window pattern window = Pointer to an intuition window. pattern = Word 16 characters long where "x" is an on pixel, any other character is an off pixel. Set a windows line pattern. setmenu window menu-list window = Pointer to an intuition window (@0 for command window). menu-list = List of menu text: [ menu-name-1 [ item-1-1 K ] [ item-1-2 [ subitem-1-2-1 K ] [ subitem-1-2-2 K ] ] menu-name-2 [ item-2-1 ] [ item-2-2 ] ] (where "K" is a keybord short cut) Attach a menu strip to the window. setpen window pen ( type ) window = Pointer to an intuition window (@0 for command window). pen = Number of pen. type = Number, which pen: 0 foreground pen (default) 1 background pen 2 area outline pen Set a windows pen number. setrgb screen index rgb-list screen = Pointer to an intuition screen. index = Number, index into color registers table. rgb-list = List of three numbers, containing red, green, and blue value of the color. Set a screens color register. setstyle window style window = Pointer to an intuition window (@0 for command window). style = Number, sum of: 0 = plain 1 = underlined 2 = bold 4 = italic Set the text rendering style. settdm mode ( turtle ... ) mode ( turtle-list ) mode = Number, sum of: 0 = JAM1 1 = JAM2 2 = COMPLEMENT 4 = INVERSVID turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Set turtles draw mode. settlp pattern ( turtle ... ) pattern ( turtle-list ) pattern = Word 16 characters long where "x" is an on pixel, any other character is an off pixel. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Set turtle line pattern. settpn pen type ( turtle ... ) pen type ( turtle-list ) pen = Number of pen. type = Number, which pen: 0 foreground pen 1 background pen turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Set turtles pen number. settpos position ( turtle ... ) position ( turtle-list ) position = List of two numbers, X, and Y coordinates. turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Set turtles position. show object ( object... ) object = Any word or list. Print object to command window. sin angle angle = Number representing an angle. Output sine of angle. sleep Wait for an event (mouse, menu, keyboard, or window close). sqrt number number = Positive number. Output square root of number. stick Output list containing the X position, Y position and button position of a joystick in port number two. stop Exit procedure. system action ( ? ) action = A number from 1 to 14, specifing action to be taken. ? = Listed below. Fourteen commands in one, to control memory, libraries, and demons. 1 Output the amount of memory LOGO tries to hold in reserve. 2 bytes bytes = Number of bytes. Set the amount of memory LOGO tries to hold in reserve. 3 bytes bytes = Number of bytes. Allocate memory, output pointer to block. 4 bytes bytes = Number of bytes. Allocate chip memory, output pointer to block. 5 pointer pointer = Pointer to allocated memory. Free memory. 6 Output list of pointers to allocated memory blocks. 7 Open Diskfont library. 8 Close Diskfont library. 9 Open ILBM library. 10 Close ILBM library. 11 Enable demons. 12 Disable demons. 13 Open Icon library. 14 Close Icon library. tan angle angle = Number representing an angle. Output tangent of angle. tell turtle ( turtle... ) turtle-list turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Make these the active turtles. text window object window = Pointer to an intuition window. object = Any word or list. Print text to a custom window. thing name name = Word, a variable name. Output object bound to name (contents of variable). throw label label = Any word. Escape to catch with matching label. toplevel Exit program return to top level. toward position turtle position = List of two numbers, X, and Y coordinates. turtle = Pointer to a turtle. Output heading to point turtle toward position. tpen turtle ( type ) turtle = Pointer to a turtle. type = Number, which pen: 0 foreground pen (default) 1 background pen Output the turtles pen number. tpos turtle turtle = Pointer to a turtle. Output a list containing the turtles position. turtlelist Output list of pointers to all open turtles. turtleoff ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Deactivate turtles. turtleon ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Activate turtles. twpos turtle turtle = Pointer to a turtle. Output Turtles position in window coordinates. type object ( object... ) object = Any word or list. Print object to command window. unbury name ( name... ) name-list ( name-list... ) name = Word, a variable name. name-list = List of names. Make variable names accessable. wait seconds seconds = Positive number. Pause for a number of seconds. whenchar run-list run-list = List of LOGO instructions. Set demon to run when key stroke is detected. Run-list must execute a "readchar" to clear the character queue. whenclose run-list run-list = List of LOGO instructions. Set demon to run when window-close is detected. Run-list must execute a "getclose" to clear the window-close queue. whenmenu run-list run-list = List of LOGO instructions. Set demon to run when menu item is selected. Run-list must execute a "getmenu" to clear the menu-selection queue. whenmouse run-list run-list = List of LOGO instructions. Set demon to run when mouse-button is pressed. Run-list must execute a "getmouse" to clear the mouse-button queue. while predicate-list run-list predicate-list = A run-list that outputs true or false. run-list = List of LOGO instructions. While predicate-list is true, repeat run-list. window ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Allow turtle to move beyond edges of window. windowlist Output list of pointers to all open windows. word word word ( word... ) word = Any word. Output word made up of input words. wordp object object = Any word or list. Output true if object is a word. wrap ( turtle ... ) ( turtle-list ) turtle = Pointer to a turtle. turtle-list = List of turtle pointers. Make turtle wrap around at edges of window. writepixel window X Y window = Pointer to an intuition window. X = Number, pixel x coordinate. Y = Number, pixel y coordinate. Set pixel (X,Y) to the pen color. wtpos turtle turtle = Pointer to a turtle. Output windows position in turtle coordinates. PLEASE HELP ME * * * * * * * * * * * * * * * * * * * * * * Help me to improve this version of LOGO. Please contact me with any comments or bug reports. Gary Teachout 10532 66 Place, W Everett, WA 98204 USA