Intriguing. My guess is that trag would be your natural ally in this endeavour, with his IIfx SIMM experience. On that topic: a 64-pin SIMM adapter that lets us use 30 or 72 pin RAM in those puppies would be a boon, indeed.

Click to expand...

I'm coaching baseball this season and too busy to do much thinking, much less hacking. However, I did post a rather long explanation (on AppleFritter, I think) about why there's no point in trying to adapt other memory to the IIfx.

The short version is that the vast majority of memory uses bidirectional data pins (they're both DATA_IN and DATA_OUT) whereas the IIFX has separate pins for In and Out on the Data bus and there's a very good reason why it needs them. So there's no way to adapt SIMMs which have a bidirectional data bus to use in the IIfx short of measures which amount to desoldering the memory chips and putting them on a different board.

Or building an intervening circuit board which does some tricky conversion.

And if you're going to do that, why not just build IIFX SIMMs in the first place?