PCM

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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

OpenOffice Draw file: File:Neo-pcm.odg

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