I'd like to know just so I can put my mind at ease (as I don't engineer/build myself, this is just a fact my brain wants to know ), because after seeing several of these and a few other posts about this and how it's plaguing new builds for our old machines.
I went ahead and measured a few sticks of my of-the-time 30-pin RAM and my OEM SE/30 ROM SIMM I have and they're all 1.20–1.25 mm by my caliper measurement (margin of error is usually ±0.01 mm on mine). So I don't know if I'm measuring wrong (don't know how I could with the board thickness…) or if I have mutant sockets, or what the deal is. ¯\_(ツ)_/¯
Which part of
you really want 1.27 mm. or .050", but it seems difficult to find.
did you guys not understand? Apology for appearing snarky. Not really intended.
The specification for the 30 and 68 pin sockets is for boards with .050" thickness. Converting .050" to mm yields 1.27.
Back when those SIMM sockets were current, printed circuit boards were still largely specified in inches, at least, in the USA and .050" was the specification. If you manage to look up a datasheet for the sockets, you'll find it called out there as well.
Everything went to .063" sometime around when memory moved to DIMMs, which is the common 1.6mm.