Read vcounter after each buffer run, and during the idle loop.
If there is less than n samples before vblank, set z_min_buffer to the lowest possible value to ensure we don't enter a new buffer run before or at the vblank.
Based on my calculations, we should stop buffering at 28\~35 before vblank. The vblank will last for 32\~42 samples (NTSC) or 75\~100 (PAL V28) or 61\~82 (PAL V30).
The vcounter should not be read during vblank as it requires a 68k bus request (and hence, it will cause the Z80 to be halted by the VDP if DMA is in progress)
Read vcounter after each buffer run, and during the idle loop. If there is less than
nsamples before vblank, setz_min_bufferto the lowest possible value to ensure we don't enter a new buffer run before or at the vblank.Based on my calculations, we should stop buffering at 28\~35 before vblank. The vblank will last for 32\~42 samples (NTSC) or 75\~100 (PAL V28) or 61\~82 (PAL V30).
The vcounter should not be read during vblank as it requires a 68k bus request (and hence, it will cause the Z80 to be halted by the VDP if DMA is in progress)