How do I identify RAM chip sizes and parity/non-parity RAM?
Parity SIMMs have an odd number of chips on the SIMM. Non-parity SIMMs have an even number. The following is a rough and very general guide to identifying chip sizes. There are some numbers on the chips (the individual black chips, not the whole SIMM). There are usually some letters, some numbers, some letters, and then a couple more numbers. (The following is most accurate for 30-pin SIMMs.) For example: KM41256AP-12 comes from a (disregard the KM4 part) 256 kilobyte, (disregard the AP) 120 (add a zero to the numbers after the dash) nanosecond SIMM. If they’re parity chips, read the one farthest to the right with the pins down. 4256 or variants thereof: 256KB (these make great keychains but are virtually worthless in a Mac) 1100 or 1000: 1MB 2048, 2000, etc: 2MB 4400, 4000, etc.: 4MB 8096, 8000, etc.: 8MB and so on. If this doesn’t answer your question well enough, maybe the Chipmunk RAM Guide will.
