Yamaha YM2608

It includes the SSG's three sound channels, noise generator and dual 8-bit GPIO ports.

The YM2608 became the basis for the YM2610, most notably used in SNK's Neo-Geo arcade and home console, using near-identical specifications.

On the other hand, the YM2612, most notably used in Sega's Mega Drive (Genesis) console and Fujitsu's FM Towns computers, was similar to the YM2608 in terms of its feature set and functionality, leading to many referring to the YM2608 as being the basis for the YM2612.

It removes the YM2608's GPIO ports, CSM (Composite sine mode) and the ADPCM Sound Source.

It also reduces the wait times on register access, and adds a low-power standby mode.

Yamaha YM2608