There always is that option but you need a lot of ingreedients and tools.

I'm in the mood to homebrew a batch of 1mb simms for IBM machines. The 286 25's, 30's, scsi cards and 50z machines all used special 1mb simms. You can literally mod (some) standard simms to work, but that is annoying and frankly hit or miss. Besides, I have model 25 with the memory expansion card, that ALSO uses the simms, so if I really want to pimp out my 286-25 i'm going to need 16 of the buggers.

Maybe I'm over-estimating the ease of the task, but when you look at one there really isn't all that much to them. Just the phenolic board with the traces to connect the contacts to he RAM chips and maybe a few small SMD components (not sure what those are). It seems like something that should be possible to do, especially when you are talking about the densities we would be interested in primarily: 256k, 1MB, 4MB and *maybe* 16mb for the boards that could accept those.

Which also has me wondering, if you could home brew a simm, wouldn't it also be possible to make it using SRAM and not DRAM and have a much faster memory? Or would that just not be possible? I know the Lotech EMS boards use SRAM so that is what makes me thing it would be possible but perhaps that's a different situation.

Maybe not. The memory chip has to be able to operate at the speed the board runs at. Sure with newer memory 0 WS is easier, but faster ram for the sake of it will not help in this case.

Hi guys, I have processed a lot of data to generate out my database of vintage SIMM and SIPP DRAM chips and modules:

http://martenelectric.cz/simm-sipp-ram-chip-database.html

This should be handy for those brewing at home 😀