I'm looking at the caches on Fizzbinn's excellent guide:
https://tinkerdifferent.com/resources/ppc-macintosh-l2-cache-modules.19/
Specifically in the last category for PowerSurge and Catalyst machines:
D - 7200/7300/7500/7600/8500/8600
160 pin Cache DIMM
Pin groupings: 25 - 35 - 20
Specifically, I was looking up the various chips present. It appears that this last generation of Cache modules do not use a TAG RAM with a built-in comparator, just a regular SRAM chip to act as the TAG, suggesting that the Comparator is built into the PPC or the Hammerhead/Platinum.
Just to make things confusing, a few of the caches have a couple of IDT 71B74 which contain comparators, but can also operate as a conventional SRAM. But the other modules just have plain, boring, fast SRAM chips and no comparators.
So, cache comparator in the chipset or on the cache?
https://tinkerdifferent.com/resources/ppc-macintosh-l2-cache-modules.19/
Specifically in the last category for PowerSurge and Catalyst machines:
D - 7200/7300/7500/7600/8500/8600
160 pin Cache DIMM
Pin groupings: 25 - 35 - 20
Specifically, I was looking up the various chips present. It appears that this last generation of Cache modules do not use a TAG RAM with a built-in comparator, just a regular SRAM chip to act as the TAG, suggesting that the Comparator is built into the PPC or the Hammerhead/Platinum.
Just to make things confusing, a few of the caches have a couple of IDT 71B74 which contain comparators, but can also operate as a conventional SRAM. But the other modules just have plain, boring, fast SRAM chips and no comparators.
So, cache comparator in the chipset or on the cache?