MV1A PALs

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The MV1A MVS boards have two [PAL] PAL20V8H-15 chips which are used to provide some of NEO-C1's functions. If any of them fails, the board certainly won't start up.

They can be replaced with new or working chips programmed with the following JEDEC files:

SNK1A

Does address decoding.

SNK1A pinout.png

JEDEC file: File:SNK1A.zip

SNK1B

Generates the DTACK signal.

The CN2* inputs are probably connected to the cartridge ROM speed configuration pins (ROMWAIT, PWAIT...)

SNK1B pinout.png

JEDEC file: File:SNK1B.zip