CDC 6600 Computer Cordwood Module

The Control Data Corporation, Seymour Cray's first company, designed
the CDC 6600 computer in the mid 1960s. It was very fast for its day.
The computer was made of thousands of little transistorized circuit
modules, each plugged in and screwed into a frame and cooled with exotic

The construction of this module uses the cordwood method, named because
the resistors appear to be stacked like cordwood between the two circuit
boards. I can't imagine how the designer would keep straight the connections
between the two boards, since each resistor and capacitor send the signal
from one board to the other.

Tom Jennings was nice enough to give me this module, perhaps not
realizing how rare they are these days. I've only found a couple others
pictured on the web as museum exhibits. So here are some nice big photos...


Page created February 26, 2009 by David Forbes