So you've bought a dead mac classic. The logic board is bombed, and there's no expansion board inside. Or there was, and it, too, has incurred the wrath of Maxell. Well, you now know you can get a Macintosh Classic Reloaded board, at least, but what about the RAM expansion? Well - between @Branchus and myself, i've worked on this in Sprint in my limited spare time lately.
The board as it stands, once populated with 256x4 SOJ RAM chips, will give you an additional 1MB of RAM, with the SIMM sockets allowing you to add a further two 1MB SIMM's. It won't work with anything larger than 4MB - that's a restriction the BBU chip imposes (limited address lines).
I currently have 5 of these in production, fully populated with everything bar the through hole components.
Project is available on GitHub here: https://github.com/kr239/Macintosh-Classic-Reloaded-RAM-Expansion-Board
The board as it stands, once populated with 256x4 SOJ RAM chips, will give you an additional 1MB of RAM, with the SIMM sockets allowing you to add a further two 1MB SIMM's. It won't work with anything larger than 4MB - that's a restriction the BBU chip imposes (limited address lines).
I currently have 5 of these in production, fully populated with everything bar the through hole components.
Project is available on GitHub here: https://github.com/kr239/Macintosh-Classic-Reloaded-RAM-Expansion-Board