I was curious if anyone here has seen the optional cache modules for a Compaq Presario 850 or an ALR Flyer 32DT.

The Compaq part number is 197005-001, which is a 128kb module. I've been trying to find one for several years now, but none of the sources I found actually had stock.

The ALR is a complete mystery. I can't even find an owner's manual for that system. Apparently it had quite a few options though, with dual CPU sockets, interchangeable CPU cards, and different types of disk controllers. It's got a mystery slot near the back corner of the board, and the cache slot looks a lot like a PCI connector that sits right next to the CPU card.