Delete comment from: Ken Shirriff's blog

ka1axy said...

IBM really pushed the technological envelope. AT&T/Bell System as well. They made everything themselves and it's interesting to see (1) the price/performance ratio, and (2) how their products departed from everyday industrial and consumer equipment.

I remember tearing apart a Western Electric PBX line card once. It was a metal-core, ceramic insulated PCB. This was in the 70s. Their stuff was designed to be put into service and left there forever. I have a 1968 date coded WE 565 telephone on my desk. It is (with the exception of the "rubber" feet, which are corroding the steel chassis) as good as the day it was made.

Apr 16, 2021, 12:36:41 PM

Posted to Teardown of a logic chip from a vintage IBM ES/9000 mainframe