Somebody did a very "Low Rent" version of one back in the day. It was done using wires and SIMM Sockets clustered and flopping about on the existing socket. Dr. Bob over on 'fritter called it something like: the most evil thing he'd ever seen.
I've always wondered if the Q605 & LC475 (among others) could benefit from a new approach to memory expansion. I nabbed an extra MicroQuadraFeetsMac™ on eBay and want to try to boost the memory with a sub-basement memory card hack, especially so now that we've got access to the requisite SIMM Sockets thanks to olePigeon.
My plate is over-full doing research for several other hacks ATM, so I thought I'd throw this one out there for the rest of the MLA to mull over.
Here's the concept:
It's basically a SIMM Saver Card done in reverse., funneling the existing Memory Bus and all available bank select lines
to a card that adapts the memory bus by splaying it out/funneling it into a SIMM or DIMM Socket(or sockets) of a higher capacity generation of memory than was available on any given Mac. This would include stealing the bank select line from the pitiful allotment of MoBo RAM hobbling every compact mac, LC & Perfoma ever equipped with this BS.
Solder "Machine Pins" onto the bottom of the existing SIMM Socket that will mate up with the same pins installed on the sub-basement "Reverse SIMM Saver" Daughtercard.
Develop/adapt a "Virtual Memory" init/whatever to allow the Mac to address Memory FAR ABOVE the meager amount provided for by the memory mapping supported by System ROM. This was commonly done on SIMM equipped SE (and other) Accelerator Cards back in the day and shouldn't be difficult to reverse engineer/hack by one of our Low Level Programming Capable Comrades.
Research to be done:
Post links here to . . .
. . . original hack, in the threads here and over on 'fritter. < where are you Danamania?
. . . any discussions on "expanding the memory envelope" of any
Mac any of you folks are interested in MemHacking™
The we can interactively come up with an interesting solution.
BTW, the same thing should be possible to do on an actual SIMM Card designed for our beloved IIfx playtoys!
Personally, adapting this hack to my pet IIsi was my original inspiration, but sharing the notion up front (and the work!
) seems like the best course of action.
I work best in collaboration and procrastinate best when left to my own devices!
p.s. OOPS! wrong forum! gotta move this one to hacks.