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Macintosh IIfx - SRAM compatibility

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Kai Robinson
TinkerDifferent Board President 2023
Worthing, UK
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Joined: Sep 2, 2021
Posts: 1,322
Likes: 1,313
May 23, 2024 - #1
On the IIfx and the IIfx Reloaded, the two Peripheral Interface Chips use a 65C02 core running at 4MHz - they require SRAM to operate.

Here's a quick list of pin compatible 32K x 8 SRAM chips.

Manufacturer
Part Number
LyontekLY62256
SonyCXK58257AP
ToshibaTC55257BFL
NECuPD43256
OKIMSM51257AL
SamsungKM62256CLG-7
HynixGM76C256CLFW
FujitsuMB84256MB84256

Liked by trag,Volvo242GTandCallan

Bolle
Tinkerer
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Joined: Nov 1, 2021
Posts: 55
Likes: 95
May 23, 2024 - #2
On a reloaded board you can just go for ISSI IS61C256AL in SOJ-28 which is still in production.
I made the pads for the SRAM large enough to take both, SOJ and the original wide SO footprint.

Liked by Jockelill,trag,Volvo242GTand 2 others

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