The Jim Austin Computer Collection

Cray 1 card

From s/n 1 machine

Cray 1 card


This is a card from a cray 1. The machine is shown on the right. It is the most important supercomputer. as it set the base line for all other machine.

This card comes from the very first of this machine, and joined the collection in 2009. This is the text Richard Porter supplied on the card when I recived it from him. You can see the machine serial number on the top of the card.

Cray Research, Cray 1, AR Module serial number 0186

Just a short note to confirm the authenticity of the AR module and some background on the history of the first Cray 1 (aka serial number 1).

Serial number 1 was the first system produced by the newly formed Cray Research, and was announced in 1975. It was first delivered to Los Alamos Scientific Lab. In 1976. From here it went to ECMWF (European Centre for Medium Range Forecasts) based at that time in the Rutherford Labs, Didcot. From here it went to various sites, ending up at a government lab in the west of England.

The system had an 80MHz, 12.5 nansecond clock(3 ns width) and a 64 bit word. It had 12 fully segmented functional units. It also had vector and scalar instructions/modes and full floating point arithmetic capability.

The AR module is a  part of the 8 X 24 bit “Address Registers” and were primarily used as address registers, but were also used for loop control, shift counts and channel control (I/O block size).

The printed circuit board is a 5 layer board, the 2 outside layers are for signal runs, and internally there are 3 for -5.2v, -2.0v and ground. The module was cooled by being clamped at either side by a “coldplate” that was cooled using Freon R22.

One other interesting point about the build of this module is that the edge connector and test point strip are both green, this is unique to “serial number 1”, all other modules were built using white/cream coloured Cinch parts.

On this particular module you can see signs of multiple repairs which indicate that this module has been in and out of “Serial Number 1” on several occasions. This module was given to me by one of the service engineers that worked on this system, and was not in the system (it was in the spares pool) at the time it was powered down. Most of the other spares were scrapped..

From looking at the web pages of the Chippewa Falls Museum in Chippewa Falls, Wi., it would seem that this system is now back in the US.  See links below.

Here is a shot of the other side of the card.

Cray 1 card