IM 2

[britlion]

And the results are positive. INKEY$ doesn't neeed the BASIC ISR. So, unless I need to use the FRAMES system variable, I can skip calling the BASIC ISR from my own ISR.

You could do it faster yourself. Berksman does this itself. When playing a sound, it goes to IM2, which updates FRAMES and nothing else, as quickly as I could This lets the clock stay in sync in the middle of a sound and doesn't affect the sound too badly. (I can barely hear it)..

Code:

isr:
asm
;This is the interrupt Service Routune
; First thing, save those registers.

PUSH AF
PUSH HL

;Kick the clock forward because we lost at least a frame.
LD HL,23672
INC (HL)
JR NZ, ISREnd
INC HL
INC (HL)
JR NZ, ISREnd
INC HL
INC (HL)

ISREnd:

POP HL
POP AF

reti
end asm