Askaris Technical Director Sean Allison has just spent the entire weekend at Bletchley in Milton Keynes. Bletchley is now famous as the once top secret location of the World War II codebreakers of the Enigma and Lorenz encryption devices. However, Sean’s purpose down there was somewhat less glamorous. He spent the weekend along with his brother Ray in a darkened warehouse that was filled with mini and mainframe computers from the 1980s belonging to the National Museum of Computing. The computing museum lies in the grounds of Bletchley Park in one of the old codebreaking huts (Block H), where they have a working Colossus and Tunny machine – these were collectively responsible for breaking the incredibly strong Lorenz encryption in 1942 in use by the German high command during the war (Enigma had been cracked earlier in 1940 using Alan Turing’s Bombe machine).
Askaris Technical Director Sean Allison in the early stages of restoration
Both Sean and Ray were field engineers in the 1980s and specialised on the once widespread DEC PDP computers. DEC (which was an acronym for Digital Equipment Corporation) was acquired by Compaq in the 1990s, and then subsequently Hewlett Packard. These machines were incredibly versatile and ran applications from accounts and sales systems to nuclear power station controllers and seismic activity analysis.
The particular machine being worked on was a DEC PDP 11/70 from 1977. These machines were manufactured in Massachusetts in the USA but were also later built in Leeds, West Yorkshire via an OEM called Systime, who Sean and Ray both worked for.
Their task was to revive the 40 year old system and its original operating system in order to retrieve the applications stored on it. Known internally at the museum as the Scrapbook system, it was a hypertext based system which predates Tim Berners Lee’s invention of the World Wide Web by some 7 years.
The label from the Computing Museum’s archives
The system had two 67Mb disk drives which had removable disk packs. These disk drives took 2 people to lift them and used incredible amounts of power. At a cost of £12,000 each in the 1980s, engineers would repair these drives in the field down to component level.
The rebuilding of the Scrapbook machine is a slow job and several more visits are required to dismantle, thoroughly clean and re-assemble the drives before they can safely power them up without risk of causing a head crash – which would completely destroy the disk packs and along with them, the only one of this iconic system left in existence. No pressure then!
Disk pack mounted in the drive ready for spinning up – a whole 67Mb – enough to store around 10 photographs from your iPhone!
Chairman of Askaris, Richard Upshall commented; “It’s great to be part of history, and I’m happy to see Sean indulging in this remarkable project. Having missed out on the opportunity to obtain the Bremont Codemaker SS watch when it was released, it is good to somehow be connected with that part of history”.