Popular 1960's British computer still putting on a show

TNMOC volunteer Peter Onion reports on the success of one of Britain’s iconic machines, both in industry and as one of the larger, working exhibits at the National Museum of Computing.

This coming weekend at the Vintage Computer Festival at TNMOC, I will as usual be found tending the Museum’s oldest original operational computer, an Elliott 803. In fact this weekend, I’ll be giving formal talks on it too.

The Elliott 803 was a very popular machine in its day with over 200 being sold between 1960 and 1965 (in 2011 we are hoping to arrange a celebration for the 50th anniversary of the first shipment of an 803B). The 803 was used in a wide variety of business, industrial, scientific and military applications and luckily a list of Elliott’s 803 customers has survived, which included:

  • The GPO who used an 803 at their Goonhilly Downs satellite earth station to calculate the path of the first communications satellite, Telstar enabling reception of the first transatlantic satellite TV pictures in 1962.
  • Corah Knitware in Leicester who managed their orders and production on a pair of 803s.
  • A poultry farm in Yorkshire who used their 803 to analyse each hen’s egg production to aid their chicken breeding program.
  • Several 803s were shipped overseas with some eventually finding their way to Russia and other Eastern Block countries. Some even went to the USA as part of industrial process control systems!

The TNMOC Elliott 803B was manufactured in 1962 and apart from a period of about 12 years in a barn has been in regular use ever since. It was the first “large” machine to be installed at TNMOC.

Almost every week, I have the pleasure of hearing TNMOC visitors say: “I used one of these when I worked at …….”. Some of them were employees of Elliott Automation who installed or maintained 803s and some were students who used an 803 at university to analyse their research.

Of course most of our visitors have never even heard of the Elliott 803, so it is always a pleasure to give them a potted history of the machine. For many of them it is the largest computer they have ever seen close-up – that is until they move on past the 803 and are confronted by TNMOC’s huge ICL 2966 installation.

More technically minded visitors can get treated to an in-depth discussions of the finer points if the 803’s design. Once explained, its unfamiliar serial architecture and seemingly bizarre 39 bit word length are often described as “clever” or “ingenuous”. But those were the days before the byte ruled over machine word sizes, and when the lower gate count and smaller physical size of a serial computer made a machine affordable to many more potential customers. The 803 was the last of Elliott’s serial machines with all its successors using parallel architectures.

The ultimate demonstration of our 803 is to see and hear it running its Algol 60 compiler. The compiler was produced by a small team of only three programmers led by Tony Hoare (now Professor Sir Tony Hoare), and the availability of such an advanced high level language made a major contribution to the commercial success of the Elliott 803.

Peter Onion leads the Elliott 803 restoration team at the National Museum of Computing. You can find him at the VCF this weekend in the Large Systems Gallery where he will also be giving talks on the 803 at 12.15 and 15.15 each day.