PCM

NEO-PCM chip found in a MVS cartridge. Picture courtesy of [MVS-Scans].

V ROM banking and multiplexing chip, found in AES and MVS cartridges.

NEO-PCM2 can also be found in late cartridges and with NEO-YSA2 on ROM-only arcade boards.

On some cartridge boards, V A20~V A22 can be used to select which of the 4 possible V ROMs to use (decoded by a LS139).

Pinout

File:Pcm pinout.png

Not sure about A19.

• SDPOE, SDROE, SDPMPX, SDRMPX: from the YM2610

• SDRAD0~SDRAD7: ADPCM-A data bus
• SDPAD0~SDPAD7: ADPCM-B data bus

• SDRA8,SDRA9,SDRA20~SDRA23: ADPCM-A address bus
• SDPA8~SDPA11: ADPCM-B address bus

• V D0~V D7: V ROM(s) data bus
• V A0~V A21: V ROM(s) address bus