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- Older models took straight DRAM chips, but many of the newer models used 30 pin
SIMMs, there were even a few used 72 pin SIMMs.
- If the system used SIMMs, the 30 pin type had to be installed in full banks. This
meant that to get 4MB of RAM, you had to install four 1MB SIMMs.
- If it used 72 pin SIMMs they could be installed one at a time. i.e. to get 4MB,
you installed one 4MB SIMM.
- Normally required 70 or 80ns speeds.
- Generally used parity.
- Used SIMMs of 30 pin or 72 pin FPM.
- 30 pin SIMMs were still installed in full banks.
- 72 pin SIMMs could be installed one at a time.
- 60 or 70ns speeds
- Depending on the motherboard, you could use either parity or non-parity.
Pentium, Pentium Pro, and Pentium II Systems
- Use 72 pin SIMMs or 168 pin DIMMs
- ECC or non-parity depending on the system, but usually non-parity EDO, FPM, or
- DIMMs are buffered or unbuffered but could not be used simultaneously.
- 72 pin SIMMs are installed in pairs and DIMMs singly.
- 50, 60 or 70ns speed
- Generally non-parity, but some motherboards could use ECC (Error Checking and