A 48Khz digital music player for the Commodore 64 (2018)

[panic]

http://brokenbytes.blogspot.com/2018/03/a-48khz-digital-music-player-for.html

[meithecatte]

I don't understand why the `sidtable' conversion is done at run-time. It looks as if one could save quite a few cycles at no size cost by doing it when encoding.

[boomlinde → meithecatte]

The values in the table depend on the SID model. So on an older SID (6581) you have one table, and on newer SID (8580 or 6582) you have another.

[PunksATawnyFill]

Meanwhile, the Atari computers had a “volume-only” mode that let you send a voltage directly to the audio output.

By setting the paddle ports to a high-speed sampling mode, you could easily build an audio sampler.

Great computers.

[dang]

Discussed at the time: https://news.ycombinator.com/item?id=16696246

[jcmeyrignac]

Another trick is to put the replay routine in zero-page, so you can easily increment the pointer. It saves one cycle.

[vardump]

Not just PCM playback, but also realtime decompression, vector quantization.

About 2 bits used per 8 bit sample.

About 7 bits of PCM resolution out of good old SID chip.