The world's oldest original working digital computer springs back to life and is going on display at The National Museum of Computing in Buckinghamshire.
The Witch, as the machine is known, has been restored to clattering and flashing life in a three-year effort.
A happy accident led to its discovery in a municipal storeroom where it had languished for 15 years.
Cleaning up
The machine will make its official public debut at a special ceremony at The National Museum of Computing in Bletchley Park on 20 November.
Design and construction work on the machine began in 1949 and in 1951 was one of maybe a dozen. It weighed a massive 2.5 tonne which is a little more than todays iPad weighing in at 1.44 pounds (652 g).
The machine first ran in 1951 and proved very reliable. Often cranking up 80 hours of running time per week.
By 1957 the machine was being exceeded by faster, smaller computers and it was handed over to the Wolverhampton and Staffordshire Technical College who began to call it 'Witch' (Wolverhampton Instrument for Teaching Computation from Harwell).
In 1973 it went on display for 24 years until 1997 at Birmingham's Museum of Science after being donated and remained there untll museum closed and the machine was dismantled and put into storage.
On subsequent trips to the storage facility the various parts of the Witch were found although pretty dirty it had not too much physical damage and the restoration began. Conservationist Mr Delwyn Holroyd said the vast majority of the parts on the machine, including its 480 relays and 828 Dekatron tubes, are entirely original. "It's important for us to have a machine like this back in working order as it gives us an understanding of the state of technology in the late 1940s in Britain." said Mr Murrell, one of The National Museum of Computing's trustees and discoverer of the great find.
Specifications:
Power Consumption: 1.5kW
Size 2m high x 6m wide x 1m deep
Weight: 2.5 tonnes
Number of Dekatron counter tubes: 828
Number of other valves: 131
Number of relays: 480
Number of contacts or relay switches: 7073
Number of high speed relays: 26
Number of lamps: 199
Number of switches: 18
