Difference between revisions of "NEO-MGA"

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|date=1994 ?
 
|date=1994 ?
 
|gates=?
 
|gates=?
|used_on={{PCB|CDROM-2}}...
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|used_on={{PCB|CDROM-2 board|CDROM-2}}, {{PCB|MV1A}}...
 
}}
 
}}
  
NEO-MGA is a custom chip apparently noone knows about, which is found in 3 versions in CD systems and some late MVS boards:
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Multi-purpose chip found in CD systems and some late MVS boards:
 
* NEO-MGA in the CD1 model (front loading).
 
* NEO-MGA in the CD1 model (front loading).
* {{Chipname|NEO-MGA-T}} in the CD2 model (top loading) and {{PCB|MV1A}} MVS boards. Probably the same but made by Toshiba.
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* {{Chipname|NEO-MGA-T}} in the CD2 model (top loading) and {{PCB|MV1A}} MVS boards, can be swapped with NEO-MGA.
* {{Chipname|NEO-MGA-T2}} in the CDZ, probably with a different pinout and maybe stuff related to the [[copy protection]] system.
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* {{Chipname|NEO-MGA2-SA}} in the [[CDZ]], replaces the {{Chipname|LC8953}} ?
  
It is used for communication between the main board and the [[CD modules|CD module]], for handling [[DRAM]] access (?), address decoding (?) and for buffering [[CDDA]] data.
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It is used for address decoding, communication with the [[CD drive]], for refreshing {{Chipname|68k}} [[DRAM]], and for buffering serial [[CDDA]] data.
  
=Pinout=
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=CD pinout=
  
[[File:Neo-mga.png]]
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[[File:Neo-mga_CD_pinout.png|700px]]
  
1,10,15,16,18,30,41,50,59,70,81,90,110,121,130,139,150: Ground.
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[[File:Neo-mga_cd.odg]]
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=MV1A pinout=
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[[File:Neo-mga_MV1A_pinout.png|700px]]
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[[File:Neo-mga_mv1a.odg]]
  
 
=Signals=
 
=Signals=
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 +
* DRM*, RAS, CAS, WRITE: See TC514400 DRAM datasheet.
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* X*: See [[LC8953]] datasheet.
  
 
[[Category:Chips]]
 
[[Category:Chips]]

Revision as of 15:12, 1 August 2022

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, can be swapped with NEO-MGA.
  • NEO-MGA2-SA in the CDZ, replaces the LC8953 ?

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.