TECH TIPS

POKE 16,64:POKE 53774,112 will disable the [BREAK] key.  To keep the key disabled, you must use these POKEs after every PRINT, OPEN and GRAPHICS statement.

PEEK (53770) will produce a random number between zero and 255.

If you need to enter DOS, but you don't want to lose your program and you don't have a MEM.SAV file-Create a MEM.SAVE file from BASIC by typing X=USR(5947) NOTE: To return to BASIC, XL owners must press the [RESET] key after the disk stops turning.  The 400 and 800 will generate an ERROR 9 message when the MEM.SAV file has been created.

These instructions let you use filenames with numbers, punctuation marks and lowercase letters with DOS 2.0S.  To make the changes permanent, type {H} to WRITE NEW DOS FILES when the DOS menu appears.
   POKE 3818,33:POKE 3822,123:DOS

Typing X=USR(3352) will format your disk from BASIC.

This routine uses the Atari's realtime clocks to keep track of elapsed seconds:
   10 POKE 18,0:POKE 19,0:POKE 20,0
   20 TIMER=INT((PEEK(18)*65536+PEEK(19)*256 + PEEK(20))/60+0.5)