Memory Upgrades

Memory upgrades should be carefully studied. You must  have the right type for 
your computer.

Older computers use DRAM chips. Some early 386 computers use SIPP type memory, 
similar to SIPPS, but with wire pins. SIMM memory comes in many types including 
30 pin and 72 pin standard SIMMS as well as many proprietary types. Most 
manufacturer specific motherboards also have manufacturer specific memory 
including IBM, Compaq, Packard Bell, Dell, and others.

Memory also comes in speeds, typically 80 ns, 70 ns, and 60 ns. Memory should 
also be matched in speeds. The speed stamped on memory is usually only a group 
speed meaning that it is usually faster than stamped. 

Memory quality is also a factor including speed drift. There are also 8 bit and 
9 bit memory. 9 bit memory has a built in parity check and is much higher 
quality. There is also memory modules with dummy parity chips and only a tester 
can show them up. 

Obtain your memory from a reliable source and with a warranty.