Connectors: Both contact surfaces must also be the same material?

Paul Birkel pbirkel at
Sun Jul 10 03:14:07 CDT 2016

Stated Tothwolf tothwolf at


"Both contact surfaces must also be the same material or tin oxide will form
on the surface of the gold plating and cause a major headache. This was a
serious problem with 486 and earlier Pentium PCs with 30 and 72 pin SIMMs
and it led to a number of lawsuits."


Almost every DEC System Unit ("backplane") that I've ever seen uses
tinned-contacts, yet the Modules all use gold-plated fingers.


How does that situation jibe with the SIMM issue/experience?




More information about the cctalk mailing list