VRAM transfers + nice sound
Posted: Mon Sep 24, 2012 5:19 am
http://tiido.rocketcat.info/BitShit/ANIM.BIN
I had quite a bit of fun getting things to a point where animation is still fast and sound does not suffer from VDP FIFO overflow induced system halts.
Reading VDP control port breaks address pointer so I had to do things in a blind manner, move data and wait and move again hoping things work.
I start off sending data in tile quantities using 68K loop (68K cannot overwhelm VDP in VBL) and unlike DMA, 68K won't keep bus closed off from Z80. I switch to slow update loop when there's active display.
I coded a new WAV playback program for this one, my old code is just horrible haha. I am very happy with this one, it took me a while to do but it works like a charm.
26.5KHz, so this means sounds best on real hardware ! (emulators seem to have problems with high PCM rates).
I had quite a bit of fun getting things to a point where animation is still fast and sound does not suffer from VDP FIFO overflow induced system halts.
Reading VDP control port breaks address pointer so I had to do things in a blind manner, move data and wait and move again hoping things work.
I start off sending data in tile quantities using 68K loop (68K cannot overwhelm VDP in VBL) and unlike DMA, 68K won't keep bus closed off from Z80. I switch to slow update loop when there's active display.
I coded a new WAV playback program for this one, my old code is just horrible haha. I am very happy with this one, it took me a while to do but it works like a charm.
26.5KHz, so this means sounds best on real hardware ! (emulators seem to have problems with high PCM rates).