The Register® — Biting the hand that feeds IT

Feeds

Brit 2.5-tonne nuke calculator is World's Oldest Working Computer

Elderly giant takes 10 seconds to divide a number

Britain's hefty Harwell Dekatron is back in the Guinness Book of World Records after being recognised - for the second time - as the world's oldest working digital computer.

The 2.5-tonne number-crunching goliath began life at the Atomic Energy Research Establishment in Harwell, Oxfordshire, in 1951, and put reliability over processing speed.

The wall-sized calculator - also known as the WITCH computer - held the record for being the planet's oldest operative computer for several years before it was decommissioned in 1973. Last year's reboot brought the ancient ticker back to life and allowed it to regain its title. It took three years of work by volunteers to restore the huge machine to its full working glory.

With 828 Dekatron tubes - used to build chains of counters and frequency dividers - and 480 relays and a user interface of 199 lamps, the whirring machine is a useful teaching tool, according to The National Museum of Computing where the beast nows lives and computes.

A video of the restoration process is on Youtube here:

Those specs in full:

  • 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

The WITCH is available to visit at The National Museum of Computing in Bletchley Park. ®

And if you talk to the people working on it,

They are immensely knowledgable and keen to share that knowledge.

The gentleman ("I know valves, not computers") who took time out to explain the machine and how it worked to my niece last year, then got her to step it through to demonstrate how it processed a calculation deserves my thanks. If there's been a bar handy, I'd have offered him a pint. Thank you Sir!

10
0

I love it... after using computers to fight fascism in Europe, we British then use computing for our second highest priority: ensuring we have enough cups of tea and cake.

8
0

Still better speed...

than most versions of windows. :D

In all seriousness, they did a fantastic job of recovery and restoration to make sure an important machine is kept for future generations to enjoy and learn from.

8
0

Dekatron

Looked it up on Wikipedia. Want.

http://upload.wikimedia.org/wikipedia/commons/f/f7/Dekatron.gif

7
0

what did it calculate?

I have it on good authority that it came up with "BOOBIES"

6
0

More from The Register

Pirates scoff at games dev sim's in-game piracy lesson
Dev seeds cracked version of 'Game Dev Tycoon', watches as Pirates run rampant
Fanbois vs fandroids: Punters display 'tribal loyalty'
Buying a new mobe? You'll stick with the same maker - survey
iPhone 5 totters at the top as Samsung thrusts up UK mobe chart
But older Apples are still holding their own
Google to Glass devs: 'Duh! Go ahead, hack your headset'
'We intentionally left the device unlocked'
Japan's naughty nurses scam free meals with mobile games
Hungry women trick unsuspecting otaku into paying for grub
 breaking news
Turn off the mic: Nokia gets injunction on 'key' HTC One component
Dutch court stops Taiwanese firm from using microphones
Next Xbox to be called ‘Xbox Infinity’... er... ‘Xbox’
We don’t know. Maybe Microsoft doesn’t (yet) either
Sord drawn: The story of the M5 micro
The 1983 Japanese home computer that tried to cut it in the UK
Nudge nudge, wink wink interface may drive Google Glass
Two-finger salutes also come in handy, as may patent lawyers
Black-eyed Pies reel from BeagleBoard's $45 Linux micro blow
Gigahertz-class pocket-sized ARM Ubuntu rig, anyone?