I have a non-working Mac IIci. I'm trying to identify the 8 installed SIMMs, see attached pics. I suspect the four chip SIMM is a 1MB (total of 4MB) and the 8 chip SIMM is a 2MB (total of 8MB), but since the machine won't start, I can't tell. There is nothing printed on the backs of any of the SIMMs. Searching for information about the specific chips has not been helpful (to me, at least). Any advice is appreciated.
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Identify Mac IIci SIMMs
- Thread starter JBurian
- Start date
bear
Veteran Member
KM41C400 is 4 megabit (each chip gives 4 M x 1 bit). 8 chips gives you 4 MB. 4 SIMMs each with 8 chips gives you 16 MB.
HY514400 is also 4 megabit (arranged differently, each chip gives 1 M x 4 bits). 2 chips gives you 1 MB. 4 SIMMs each with 4 chips gives you 8 MB.
HY514400 is also 4 megabit (arranged differently, each chip gives 1 M x 4 bits). 2 chips gives you 1 MB. 4 SIMMs each with 4 chips gives you 8 MB.
GiGaBiTe
Veteran Member
Those are some weird SIMMs you got there. The first looks to use ZIP chips at a 90 degree angle. It also has what looks to be polystyrene capacitors. The second uses a PLD, I'm assuming to generate a parity signal.
bear
Veteran Member
The PLD is a Mac thing for decoding what amounts to a "double" SIMM.