The Harwell (WITCH) Computer
WITCH
Originally used at Harwell from 1951-57 and then won by Wolverhampton College, renamed the WITCH and used for teaching computing until 1973.






Photo: The Harwell Dekatron Computer © LSA June 2012.
| EXIT | WITCH |

Overview

Originally used at Harwell from 1951-57 and then won by Wolverhampton College, renamed the WITCH and used for teaching computing until 1973.

WITCH stands for Wolverhampton Instrument for Teaching Computing from Harwell. 

The WITCH is on loan from the Computer Conservation Society and was moved to Bletchley Park in September 2009. It was successfully rebooted on 20th November 2012.
The Harwell WITCH
The WITCH
The WITCH uses dekatron valves in the counting process.







Photo: The Harwell Dekatron (WITCH)Computer exhibition © LSA June 2012.
Pre-2000 type relay cans
Parts of the computer use Post Office pre-2000 type relay cans!




Photo: The Harwell Dekatron (WITCH)Computer © LSA June 2012.
PO 3000 type relays
Parts of the computer use Post Office 3000 type relays.

At this instant, the armatures of the SDY and SEY relays appear to be transposed.








Photo: The Harwell Dekatron (WITCH)Computer © LSA June 2013.
The Harwell Dekatron Computer by Kevin Murrell and Delwyn Holroyd.
The Harwell Dekatron Computer by Kevin Murrell and Delwyn Holroyd. Published in 2013 by the The National Museum of Computing.









Scan: TNMoC book.

Design, images and text compiled by © Light-Straw. Page last updated August 2015 revision. Checked May 2021.

All logos and trade marks are the property of their respective owners and are used on the Light Straw site(s) for review only. Students and researchers are recommended to make their own independent enquiries as to the accuracy of the information contained therein.