Changes

The PSG chip family is composed of 3 variants: the AY-3-8910 with two 8-bit I/O ports, the AY-3-8912 with one 8-bit I/O port and the AY-3-8913 with no I/O port. In addition to the CPC, these chips were also used in the [[ZX Spectrum]], [[MSX]], [[Oric]], [[Vectrex]] and [[Intellivision]].

Yamaha produced a derivative SSG (Software-controlled Sound Generator) chip family. This chip equips the [[Atari ST]]. The main difference between the SSG and the PSG is that the internal SSG offers 32 volume control of levels for the D/A converter has 32 levels instead of envelope, while the PSG provides only 16.