Loadstar 20/020.d81/t.datastater

Text File | 1986-01-01 | 4.8 KB | 292 lines

             DATASTATER
       A Utility for the C-128



Written by: Louis F. Sander



  Datastater is full-featured program

for converting machine language,

sprites, or other sections of memory,

to BASIC data statements. The program

takes advantage of several features of

the machine: the built-in machine-

language monitor, the escape sequences

used in screen editing, and the

hexidecimal-to-decimal conversion

function. For ease of typing and

improved understanding, the data

statements produced are in hexidecimal

notation.

  Running Datastater is simple, and

the program even includes brief

instructions.  However, you should be

familiar with using the MONITOR

command to call up your machine-

language monitor, and with using that

monitor's 'M' command to dump memory

to the screen.

  Your first step is to decide what

area in memory you want to convert to

data statements. Get into the monitor

by typing MONITOR<RETURN>, then use

the "M" command to display the

desired memory range. Since

Datastater manipulates the screen

display, it will convert a maximum of

16 monitor lines at a time, which is

equivalent to 128 bytes of ML ($80

bytes in hex). If you need to convert

more, just break the project into

manageable parts.

  When the desired memory range is

displayed on the screen, use the

monitor's "X" command to exit back

to BASIC. The memory dump display, of

course, will remain on the screen.

Using your cursor-down key, scroll

that display upward until its first

line is on the top line of the

screen.

  Then move your cursor until it's on

the line just below the last monitor

line you want to convert to data, in

the leftmost screen position. It

doesn't matter if that line is blank

or not, as long as the cursor is at

the left margin.

  To initiate a conversion, just type

the word RUN, plus a colon, and then

press RETURN. (The colon is there in

case the cursor is not on a blank

line). By the way, when you run

Datastater, it checks to see that a

monitor dump is actually on the top

screen line; if it isn't, you're

shown a series of instructions.

  In a normal run, you'll be

prompted for a First Line#, and you

should respond with the number you

want to assign to your first data

line. If you respond by pressing

RETURN without entering a number,

Datastater will choose a line number

equal to the decimal value of the

ML's starting address, since that's

the most logical number to use.

  After choosing a starting line

number, you'll be prompted for a line

number interval. If you enter

nothing and hit RETURN, the interval

defaults to eight, which retains the

correspondence between the line

number and the address of the first

data item in the line.

  As soon as you choose an interval,

you'll see the monitor lines turn

into BASIC lines. After a short wait,

some other BASIC lines will appear

on the screen.

  The first one is a loop that

computes the checksum of the bytes

you have converted. (A checksum is

simply the numerical total of all the

bytes.) If your data statements are

ever typed from a listing, the typist

will appreciate having this line,

since it can be used to eliminate

errors.

  The next line is a FOR-NEXT loop

that will poke your ML into memory.

Datastater determines the start and

end of the loop, which saves effort

on your part, and reduces the chance

of error. Notice that while your ML

data is in hex, the loop is in

decimal. Smart people, these

computers.

  Finally, there are two REM lines

showing the number of data items, the

checksum, and the memory range of the

ML, in decimal as well as hex. This

information can be useful to you

later, so Datastater gives it to you

now, in a form that easily preserved.

  After all the lines have been

printed, Datastater terminates with

the cursor flashing in the "home"

position. Your BASIC lines have been

printed on the screen, but have not

yet been added to the program in

memory. You do that yourself, by

pressing the RETURN key over each

program line. If you don't want the

extra lines, use your cursor keys to

skip over them. When you're finished

with the RETURN key, your data lines,

plus the checksum, poker, and REM

lines, are in memory along with

Datastater. You can use the DELETE

command to get rid of Datastater

itself,  which will leave you with

the lines from Datastater's output.

You can save them to disk or printer,

where they can readily be added to

the balance of your BASIC program.


              ------

   This program is copyrighted by

 Commodore Microcomputers magazine.

   All rights to it are reserved.

 LOADSTAR has relieved you from the

  burden of keying in this program.

 For more complete information about

 this program, refer to the February

       1986 issue of Commodore

            Microcomputers.


>Files used: DATASTATER.128

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