04-15-2013, 03:18 AM
youtube video
This is a small project I started a couple of days ago. The goal was to attempt playback of uncompressed YM files on the NGPC (these files are register logs for the YM2149 / AY-3-8910 chips, used e.g. in the Atari ST and ZX Spectrum).
I Figured I'd have it up and running at 16 kHz in no-time.
Wrong!
I had to lower the sampling rate to 12 kHz, then 9.6, then 8, and finally to a measly 6 kHz. And at the same time I searched for ways of shaving cycles from my code, to the point where I'm now using all general-purpose registers in every register bank in my playback loop.
The output obviously doesn't sound too good with such a low sample rate - but hey, it does kinda work. And hopefully I can make further optimizations at some point.
This is a small project I started a couple of days ago. The goal was to attempt playback of uncompressed YM files on the NGPC (these files are register logs for the YM2149 / AY-3-8910 chips, used e.g. in the Atari ST and ZX Spectrum).
I Figured I'd have it up and running at 16 kHz in no-time.
Wrong!
I had to lower the sampling rate to 12 kHz, then 9.6, then 8, and finally to a measly 6 kHz. And at the same time I searched for ways of shaving cycles from my code, to the point where I'm now using all general-purpose registers in every register bank in my playback loop.
The output obviously doesn't sound too good with such a low sample rate - but hey, it does kinda work. And hopefully I can make further optimizations at some point.