you wrote
(Working on a Packard Bell model PB410a, it's a 486SX Win 3.1
 Client wants 8 mb more ram installed.
 I tried a stick of EDO (16mb) and it wouldn't boot.
 Do I need parity ram?
 Would nonparity keep it from booting?)




I also have a Packard Bell 486sx. It not the same model as yours. Mine does
not accept EDO Ram. I don't think it was available when my computer was made.
It will take conventional RAM either with Parity or Non Parity but it will not
accept some of each at the same time. My computer will accept 4, 8, 16, or 32
MB SIMMs in the first slot. the second slot will accept 4, 16, or 32 MB chips
but not an 8 MB SIMM. I added an 8 MB to it once and it wouldn't boot. Checked
the manual and sure enough that slot will not take an 8 MB simm. Hope this
helps.

Gary  South