Feeds

World's oldest digital computer successfully reboots

TNMOC's boffins help bring back WITCH

High performance access to file storage

After three years of restoration by the National Museum of Computing (TNMOC), the world's oldest functioning digital computer has been successfully rebooted at a ceremony attended by two of its original developers.

Harwell Dekatron

The Harwell Dekatron fully restored (click to enlarge)

The 2.5 ton Harwell Dekatron, later renamed the Wolverhampton Instrument for Teaching Computation from Harwell (WITCH), was first constructed in 1949 and from 1951 ran at the USK's Harwell Atomic Energy Research Establishment, where it was used to process mathematical calculations for Britain's nuclear programme.

The system uses 828 flashing Dekatron valves, each capable of holding a single digit, for volatile memory, plus 480 GPO 3000 type relays to shift calculations and six paper tape readers. It was very slow, taking a couple of seconds for each addition or subtraction, five seconds for multiplication and up to 15 for division.

But it had persistence, performing calculations more accurately than human mathematicians and without needing toilet breaks, sleep, or a social life. When a leading mathematician tried to keep pace with the computer, he lasted for around 30 minutes before falling behind and making mistakes.

"The restoration was quite a challenge requiring work with components like valves, relays, and paper tape readers that are rarely seen these days and are certainly not found in modern computers," said restoration team leader Delwyn Holroyd in a statement. "Older members of the team had to brush up on old skills while younger members had to learn from scratch!"

Dekatron designer Dick Barnes

Harwell Dekatron designer Dick Barnes (center) meets the team

After its atomic work was finished in 1957, and with transistorized computers all the rage, the computer was offered to the academic world and ended up at the Wolverhampton and Staffordshire Technical College (thus the WITCH moniker) and ran until 1973. It was retired to the Birmingham Museum of Science and Industry, but was put into storage in 1997 before being rediscovered and rebuilt by volunteers funded by TNMOC

"In 1951 the Harwell Dekatron was one of perhaps a dozen computers in the world, and since then it has led a charmed life, surviving intact while its contemporaries were recycled or destroyed," said Kevin Murrell, trustee of TNMOC, who started the restoration project.

"As the world's oldest original working digital computer, it provides a wonderful contrast to our rebuild of the wartime Colossus, the world's first semi-programmable electronic computer." ®

High performance access to file storage

More from The Register

next story
Report: Apple seeking to raise iPhone 6 price by a HUNDRED BUCKS
'Well, that 5c experiment didn't go so well – let's try the other direction'
Microsoft lobs pre-release Windows Phone 8.1 at devs who dare
App makers can load it before anyone else, but if they do they're stuck with it
Zucker punched: Google gobbles Facebook-wooed Titan Aerospace
Up, up and away in my beautiful balloon flying broadband-bot
Nvidia gamers hit trifecta with driver, optimizer, and mobile upgrades
Li'l Shield moves up to Android 4.4.2 KitKat, GameStream comes to notebooks
AMD unveils Godzilla's graphics card – 'the world's fastest, period'
The Radeon R9 295X2: Water-cooled, 5,632 stream processors, 11.5TFLOPS
Sony battery recall as VAIO goes out with a bang, not a whimper
The perils of having Panasonic as a partner
NORKS' own smartmobe pegged as Chinese landfill Android
Fake kit in the hermit kingdom? That's just Kim Jong-un-believable!
Gimme a high S5: Samsung Galaxy S5 puts substance over style
Biometrics and kid-friendly mode in back-to-basics blockbuster
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
HP ArcSight ESM solution helps Finansbank
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.