PCM: Difference between revisions

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[[File:crt_pcm.jpg|right|thumb|NEO-PCM chip found in a MVS cartridge. Picture courtesy of [[http://www.mvs-scans.com MVS-Scans]].]]
[[File:crt_pcm.jpg|right|thumb|NEO-PCM chip found in a MVS cartridge. Picture courtesy of [[http://www.mvs-scans.com MVS-Scans]].]]


[[V ROM|PCM ROM]] banking chip in QFP96 package, found in AES and MVS [[cartridges]].
[[V ROM]] banking and multiplexing chip, found in AES and MVS [[cartridges]].


[[NEO-PCM2]] (bigger), can also be found in late cartridges and with [[NEO-YSA|NEO-YSA2]] on [[ROM-Only boards|ROM-only]] arcade boards.
[[NEO-PCM2]] can also be found in late cartridges and with [[NEO-YSA2]] on [[ROM-Only boards|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


[[Category:Chips]]
[[Category:Chips]]

Revision as of 23:30, 25 March 2011

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