hi
I started to use some module replayers (st,nt,pt) and also oldschool replayers like FC...
I seen that some player use an audio interruption (vector $70 or via audio device) and call play into VBL/VBI.
for example, I'm on Ben Daglish player :
the audio interrupt is initialized at the start :
init:...
lea autioint(pc),a0
move.l a0,$70.w
move.w #$780,$9c(a6)
move.w #$780,$9a(a6)
move.w #$c000,$9a(a6)
...
here is interruption:
intaudio:
move.w d0,(sp)
move.w $DFF01E,d0
andi.w #$780,d0
and.w $DFF01C,d0
move.w d0,$DFF09A
move.w d0,$DFF09C
lsr.w #7,d0
move.w d0,$DFF096
move.w (sp)+,d0
rte
If I don't want to use the audio interrupt and only call play at vbl, the music is playing but crash after a moment (always at the same note).
I think in others replay routine which don't use interruption, the audio interruptions are managed in another way or not managed ?
what is my question : how are managed audio interruptions in replayer without audio device or audio interrupt vector.
how/where is it implemented ?
why ben daglish crash without ? I think it's because the dma is busy when program try to write new data?
sorry for all these questions, I try to understand how works replayers.
thanks
