Tech Tips

MACHINE LANGUAGE LOADER MENU

I first encountered your MENU file when I bought the March 1989 issue with the disk enclosed. I liked the convenience of the menu, seeing all the files on disk, and being able to run a program from the menu. One thing I didn't like was not being able to run a machine language program without having to go to DOS and use the L option. (The instructions in the magazine generally tell you to rename the file AUTORUN.SYS, but the DOS option L works fine for most files ending with .OBJ or .EXE.)

This short alteration to the menu program will make it possible to execute machine language programs from the Antic Disk Menu. To work with the menu program, don't try to RUN the menu. Instead, at the BASIC READY prompt you must LOAD "D:MENU". Then you can change the lines as follows:

160 TRAP 200:POKE 83,39:POKE 82,2:FOR EXT=4 TO 12
161 IF X$(EXT,EXT+3)=".EXE" OR X$(EXT,EXT+3)=".OBJ" THEN 215
162 IF X$(EXT,EXT+3)=".BAS" THEN 164
163 NEXT EXT
164 RUN A$:TRAP 40000
215 CLOSE #1:OPEN #1,4,0,A$
216 GRAPHICS 0
217 START=USR(55760

Be sure to SAVE the modified MENU program before you RUN it, or you will lose your work.

Lines 215-217 really do all the dirty work. Line 215 opens the file for input. Line 216 sets the screen back to the original white text on a blue screen. Line 217 executes DOS option L while in BASIC.

NOTE: As far as I know, this routine works only with Atari DOS. It will only work will .OBJ or .EXE files that have been properly designed to load from DOS and run with BASIC.

COMPUTER TYPIST DEMO

This short but interesting subroutine shows how to print text onscreen character-by-character with a typewriter sound. This is the same effect you've probably seen in programs like HACKER.

When you RUN the program, instructions will write themselves out onto the screen. You can put up to 40 characters at a time into the string A$. Then GOSUB 1000 to print the characters onscreen, and move on to the text in the next A$.

If you want a different sound, just experiment with the SOUND statement in line 1030.

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