APPENDIX TWELVE



725,726        2D5,2D6        DSCTLN
     Disk sector size register; default of 128 ($80) bytes, but can be
     altered to a length from 0 to 65535 ($FFFF). Your drive may not
     support other sizes, however.

717,728        2D7,2D8        ACMISR
     Interrupt service routine address; unused.

729            2D9            KRPDEL
     Auto-delay rate; the time elapsed before keyboard repeat be-
     gins. Initially set at 48 ($30; $28 for PAL machines) for 0.8 sec-
     onds; you can POKE it with the number of VBLANK intervals
     (1/60 second each) before repeat begins. A value of 60 would
     be a one-second delay. A value of 0 means no repeat.

730            2DA            KEYREP
     The rate of the repeat; default is 6, which means ten characters
     per second (one each six VBLANK intervals after the delay
     above). POKE with the number of VBLANK intervals between
     repeats; with a value of 1, you get 60 characters per second (50
     on PAL systems)! A value of 0 provides one key repeat only per
     press.

731            2DB            NOCLIK
     This is the keyboard click disable register; POKE with any non-
     zero number to disable the annoying keyboard sound pro-
     duced through your TV. POKE again with 0 to enable the sound.
     On the 1200XL, CTRL-F3 toggles the sound as well.

732            2DC            HELPFG
     Register to hold the HELP key status; 17 is HELP has been
     pressed alone, 81 means it has been pressed with SHIFT, and
     145 with CTRL. This register can be cleared under program
     control only by POKEing it with 0. The OS ignores it otherwise.

733            2DD            DMASAV
     This saves the DMA value from 559 ($22F) on the 1200XL when
     CTRL-F2 is pressed to disable the screen. On all XL/XEs except
     the 1200XL, if you POKE 559,0 to turn off the screen, the value is
     not saved in 733. However, if you POKE 733 with the DMA value
     (usually 34) at the next keystroke, the screen will automatically
     be activated again.

734            2DE            PBPNT
     Print buffer pointer; moved from 29 ($1D) on the 400/800.