Bumping this topic after a period of inactivity.
I've got a Prolinea 4/50 with a TurboChip Am5x86-133 upgrade, and I've been thinking of procuring a 128K cache upgrade, because my system is missing it. However, it seems almost a holy grail component, because it's proprietary, and I've been searching for one for ages. But I've found one and now it's in transit to me. After all, I'd like Duke3D to run without lags. 😀
Thing is, I've been looking at the photos of that cache expansion, and it feels like it's possible to reverse it just by having photos of front and back -- there's no programmable chips on it, and all chips on it are still in supply, and are not unobtanium; though each memory chip costs $4 and there are six of them. But I have only photos of bottom.
I'm planning to use this expansion chip as a beginner exercise in reverse-engineering, and to make 2-3 units just to learn a bit. So I'm wondering -- is there at least a tiny interest in Prolinea cache expansions? I'd also extend a suggestion for anyone having a 256K expansion module to make high resolution photos of it for an attempt on reversing;
or even desoldering and scanning the board.
(I've also found a 1MB DRAM upgrade for onboard Cirrus Logic video, and it looks like it's even rarer. But also looks a bit harder to reverse)