Many HP printers take 72-pin SIMMs ("PS/2" SIMMs). What does that mean? This will depend on the type of printer you've got. Some want SIMMs with parity, some can take SIMMs with or without parity (SIMMs w/o parity are a lot cheaper). The SIMM wants parity. Actual parity, not "faux" (computed) parity. The SIMM must be FPM, 70ns or quicker. EDO memory will work in some printers, but not all. The Presence Detect pads should be related appropriately. 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 have to be related accurately. N.B.: HP's half numbers for non-parity SIMMs are C3132A, C3133A and C3146A (4MB, 8MB and 16MB respectively). There seem to be a number of part numbers for 32MB SIMM, I've seen D2298A, D3578A and KTH-NPVEC/32.

FPM stands for "Quick Page Memory". This is an old memory sort, normally found at 70ns or 80ns. Anything 60ns or quicker stands a very good probability of being EDO, though there may be 60ns FPM memory. You can not inform FPM and EDO memory apart by just looking on the module; though you may search for the half variety of the memory chips used and Memory Wave see whether or not they're FPM or EDO memory. To tell memory with parity aside from Memory Wave Program without parity, simply depend the number of memory chips on the module. If it has 9 or 18 memory chips, all alike, it has parity. If it has four or eight or sixteen memory chips, all alike, it does not have parity. In case your module has 8/16 (unlikely to be 4) memory chips after which another 1/2 chips that aren't memory (but probably "in line" with the memory chips, like this: MMMMcMMMM), then it almost certainly has computed parity relatively than real parity and is not going to work in a printer that needs parity.

What looks like a parity module may also be ECC, though; so be certain what you are getting before you get it. Regarding EDO SIMMs: Whether this works relies upon on your printer mannequin. Critically though, we have had reviews of successful use, and reports of unsuccessful use. The memory controller has to support EDO if there is to be any probability of it working. With older printer models, that might be not the case. Mixing FPM and Memory Wave Program EDO is discouraged, as a result of it's not stable at what was considered high memory access velocity in those days. Nevertheless, since HP says "80ns or slower", we do not essentially see a problem in utilizing EDO, so long as it really works: Though the built-in memory shall be FPM, and thus you might be mixing. ECC memory is error-correcting memory and will never work in a HP printer, though it can bodily fit. Concerning pace: 70ns or sooner means you can take a 60ns SIMM, encode it as 70ns, and it'll work.

We have now efficiently executed this. HP actually quotes 80ns, or "80ns or slower", however we like to be very conservative about this type of factor. SIMMs you buy nowadays can be 60ns, anyway. Proper. Pads (or pins, should you so will) 67 to 70 on a 72-pin SIMM encode the dimensions and speed of that SIMM. Every of them can both be open or related to GND (floor). Look at a SIMM you took out of your Pc. Chances are you will see traces operating from pads 67 to 70 to empty points the place a solder blob or SMD resistor would match. Pc clones, as a rule, do not use the Presence Detect pads on a SIMM. That's why the pads are (often) left unsoldered. Moreover, there isn't any commonplace for the encoding of those pads. IBM has their own means, as does HP, as does Dell, as do others.