NEO-MGA

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Cd1 neo-mga.jpg
Package QFP160
Manufacturer Logo fujitsu.jpg
First use 1994 ?
Used on CDROM-2 board, MV1A...

Multi-purpose chip found in CD systems and some late MVS boards:

  • NEO-MGA in the CD1 model (front loading).
  • NEO-MGA-T in the CD2 model (top loading) and MV1A MVS boards. Probably the same but made by Toshiba.
  • NEO-MGA-T2 in the CDZ, probably the exact same chip made with a different pinout or manufacturing process.

It is used for address decoding, communication with the CD drive, for refreshing 68k DRAM, and for buffering serial CDDA data.

CD pinout

Neo-mga CD pinout.png

File:Neo-mga cd.odg

MV1A pinout

Neo-mga MV1A pinout.png

File:Neo-mga mv1a.odg

Signals

  • DRM*, RAS, CAS, WRITE: See TC514400 DRAM datasheet.
  • X*: See LC8953 datasheet.