AY
AY is the nickname of the AY-3-8910 programmable sound generator family. The Amstrad CPC sound processor is more exactly the AY-3-8912. This chip was very popular and was used in a lot of machines.
MSX, ZX Spectrum, Atari... all used chips from this family (sometimes it was the YM variant instead of AY...). The YM variant differed only in the hardware envelopes where it used 32 steps compared to 16 steps for the AY.
As a result it is still quite popular in the actual Chip Tune movement as a vintage sound processor.
Many Chip Tune sites include AY files.
Alas, the ZX Spectrum is more often used as reference. But a huge library is available.
Contents
Amstrad Plus specificity
The Amstrad Plus range include DMA sound channels. Each HSYNC, 1 instruction per active DMA channel is read. Each channel executes an instruction which allowed looping and sending data to AY registers. Each DMA channel is effectively a AY register playlist and once started is executed without CPU intervention. It was meant to reduce the strain on the CPU.
This feature offered extra capabilities including 15Khz sample playback.
Technical references
- Datasheet AY-8913 on CPCwiki.
Chip tune
See Chip Tune page.
Links
Check the Chip Tune page.
Some Chip Tunes sites
- The AY riderz a "famous" Speccy music group.
- YM rockerz... the same concept, but with the YM, so the Atari version.
- ultrasyd.free.fr Ultrasyd's Website.
