Many HP printers take 72-pin SIMMs (“PS/2” SIMMs). What does that imply? This depends upon the type of printer you will have. Some want SIMMs with parity, some can take SIMMs with or without parity (SIMMs w/o parity are too much cheaper). The SIMM wants parity. Real parity, not “faux” (computed) parity. The SIMM must be FPM, 70ns or faster. EDO memory will work in some printers, but not all. The Presence Detect pads should be related accurately. N.B.: HP’s half numbers for parity SIMMs are C2065A and C2066A (4MB and 8MB respectively). The SIMM doesn’t need parity. The SIMM needs to be FPM, 70ns or sooner. EDO memory will work in some printers, however not all. The Presence Detect pads must be linked appropriately. N.B.: HP’s part numbers for non-parity SIMMs are C3132A, C3133A and C3146A (4MB, 8MB and 16MB respectively). There appear to be several half numbers for 32MB SIMM, I’ve seen D2298A, D3578A and KTH-NPVEC/32.

FPM stands for “Fast Page Memory”. That is an old memory type, usually found at 70ns or 80ns. Anything 60ns or faster stands an excellent chance of being EDO, though there is 60ns FPM memory. You cannot tell FPM and EDO memory apart by just wanting on the module