YM2610, aka OPNB, is a fifteen-channel sound chip developed by Yamaha. It's a member of Yamaha's OPN family of FM synthesis chips, and related to the YM2608. It was most notably used in SNK's Neo Geo arcade and home game systems, along with other arcade game system boards (such as the Taito B System). The YM2610 was used in conjunction with a YM3016 stereo DAC.
The YM2610 has the following features:
The YM2610B variant added two extra FM channels for a total of six, but was identical in every other feature. It was used in Taito's arcade boards, such as the Taito Z System, amongst others.