PPC Macintosh L2 Cache Modules

PPC Macintosh L2 Cache Modules

It seems that the 512Kb L2 cache IDT7MPV6284 (C22) is incompatible with the Power Mac 6400: the Mac chimes but doesn’t boot, no video and the power LED doesn’t even light up!

The cache module is working: I tested it with a 5500 motherboard (it only provides a 10% increase in performance in MacBench processor test!)
Fizzbinn
Fizzbinn
Interesting, that aligns with my note 1 on that module, c22, it also doesn't work in my Umax SuperMac c500 which is a very similar architecture ("Alchemy" logic board design) to the Power Mac 6400.
Hey there B01 661-1278 is in fact for the 6320, 6320CD, and 6360 it’s a 4MB ROM with a 256k Cache.
Fizzbinn
Fizzbinn
Hey, doing an update and see I forgot to reply to this. I added the 6320, 6320CD to B01. The 6360 definitely does not use this one though, I don't believe it shipped with an L2 cache but can use the ones in my "C" section, its the only 63xx Mac like this.
Very helpful. A report of my own: my 6500/275 has a 1MB cache (not Apple installed, it was after market from my parts drawer). The label reads IDT7MPV6290 S50M 9813AA.
Fizzbinn
Fizzbinn
Thanks! Could you take pictures of both side of your L2 cache module and send them to me? I'd love to add them to the table.
I've just got a 7100/66AV up and running, I've been looking out for a L2 simm for it but so far no luck, seem to be quite rare.
Never knew this, thanks!