This object is part of a collection relating to the history and development of calculating devices assembled by Assoc Professor Allan Bromley of Sydney University, comprising mathematical instruments, slide-rules, mechanical and electronic calculators, electronic analogue computers, computer components, kit computers, education computers, and associated ephemera.

Allan Bromley was a lecturer and researcher at the University of Sydney Basser Department of Computer Science from 1978 until his untimely death in August 2002. He specialised in Computer Architecture, Computer Logic and in particular the History of Computing. He was regarded as the world authority on Charles Babbage's Calculating Engines (instigating the building of the Difference Engine No.2 at the Science Museum London) and the Antikythera Mechanism and had extensive knowledge of calculators, analogue computers, logic, stereopsis, totalisators, clocks and time keeping and mechanical engineering.

Thes boards are probably from the University of Sydney, Basser Computing Department's CDC 1700 which formed the hub of their original time-sharing computer network. They illustrate the "cordwood" technique of circuit construction.

CDC 1700 manual
http://www.bitsavers.org/pdf/cdc/1700/60153100_1700Ref_Sep65.pdf

Printed circuit boards (4), transistor, metal / fibreglass / plastic, Control Data Corporation, United States of America, 1966-1975

Four similar transistor circuit boards made by Control Data Corporation. They are logic units using silicon transistors and built with the "cordwood" technique, in which the components, using axial connecting leads, are connected into the facing pair of printed circuit boards.

These particular objects are probably from a CDC1700. One of which was in the network at the University of Sydney Basser Department of Computer Science.

The front of the boards are marked: ZT - ZT - ZO3 - VO2, and the back of the boards are marked: BYKTT - BYAKTT - AYHTT- 1794540IBYITT.

Made: 1966 - 1975

2010/1/304

1966 - 1975