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Colossus and the Witch

PostPosted: Wed Dec 05, 2012 1:05 pm
by Steve Anderson
Most will be familiar with the Colossus project at Bletchley Park in the UK. The restoration of a tube and relay based computer used in anger in the closing years of WWII.

But I was unaware of this one...

http://www.bbc.co.uk/news/technology-20395212

and...

http://www.zdnet.com/uk/worlds-oldest-o ... 000007683/

This link is for the Colossus...

http://www.colossusonline.org/

...and the museum in general...

http://www.tnmoc.org/

The next time I'm in the UK I will visit! Entrance fees seem entirely reasonable.

Steve A.

PostPosted: Wed Dec 05, 2012 6:00 pm
by gary
Yes I noticed the Witch when it got a write up on Hack-a-day - I was amused to see it was installed in what I have no doubt would have been MY Technical College had I not been sentenced to transportation and put on a ship bound for botany bay just shortly after it was delivered. Who knows? I may just have got a chance to play with it before it moved on if I hadn't been... moved on...

PostPosted: Wed Dec 05, 2012 6:09 pm
by gary
hmmm I hadn't noticed that before but the second write up says that the power consumption was only 1.5kW - that seems rather low for such a "beastie".

PostPosted: Wed Dec 05, 2012 9:45 pm
by Steve Anderson
Yea, that does seem somewhat 'light'. I'm not sure which machine you're referring to, but anyway I've seen numbers banded around of around 2,500 valves/tubes of the predominantly EF36 type. These have heaters of 6.3V @ 200mA = 1.26W.

...x 2500 = 3.15kW in heater consumption alone! Add in HT current and all the other electromechanical components...I would think something in the order of 10kW is closer.

But unless someone goes there and measures the mains current with a clamp-meter we'll never know. Must have been a nice warm place to work in the British wartime winters.

Steve A.