Shopping for Power Macintosh 7300 ram

Destroyer1976

New Tinkerer
Sep 8, 2025
21
1
3
Queensland, Australia
I need help with this one.
I know the specs I should be looking for
  • EDO RAM
  • 168PIN DIMM
  • I've been told 5V
But all I've found on ebay is ECC & 3.3v RAM.
Any ideas where to get the proper ram (64MB or preferrably 128MB)
 

joevt

Tinkerer
Mar 5, 2023
240
96
28
Service Source for the 7300 says the DIMMs must be 5V and that fast paged DIMMs also work.
http://www.applerepairmanuals.com/the_manuals_are_in_here/PM7300_7500_7600_WS7350.pdf
It says you can increase the memory to 512 MB. That would require eight 64 MB DIMMs. I'm pretty sure 128 MB DIMMs should also work (my 8600 has 1 GB of RAM and it uses the same memory controller as the 7500/7600).

This article:
https://elephantandchicken.co.uk/stuffandnonsense/?p=2439
says 256 MB DIMMs can exist? I'm not sure how they would work. What would they look like to the memory controller? Should see if they can fit in the DingusPPC emulation. If they appear as 4 banks of 64 MB then that's already handled - 1.625 GiB can be added using 13 DIMM slots = 26 banks.
If they exist as 2 banks of 128 MB, then that would be interesting. Should check the schematics for sufficient address and data lines...