The LEO story: A Computer Weekly Downtime Upload podcast

The Lyons Electronic Office (LEO), is the world’s first business computer and it ran the world’s first business process on November 30th, 1951.

“In the mid 20th century, J Lyons and Company was probably the biggest catering company in the UK and maybe even Europe,” says Peter Byford, chair of the LEO Computer Society, during a podcast, where he spoke about the importance of LEO to the world of business computing. He says: “Lyons did everything themselves. There was no way they would outsource anything and so in 1949, they realised that they were getting overwhelmed by the amount of work they had to do and they wanted to automate it.”

Lyons sent two of its specialists to America to see whether there was a computer there that could perform automated processing to help the company with its office work. However, as Byford points out: “They came back with nothing.” The Americans basically said that its computers could only be used for scientific work, but not for business.

However, the team at Lyons heard that a general purpose, stored program computer was being built in Cambridge called EDSAC (Electronic Delay Storage Automatic Calculator). The stored program architecture, first proposed by John von Neumann in 1946, was the inspiration behind EDSAC: the basic idea was that code and data could be treated in the same way, and stored in memory, which meant a series of instructions (the program) could be “read” from the computer’s memory and executed on a central processor unit (CPU). Prior to the architecture von Neumann proposed, computers needed to be rewired to run different tasks.

Cambridge mathematician Maurice Wilkes, took the ideas von Neumann had presented to lead the EDSAC project. Having confirmed that EDSAC was a programmable machine, Lyons funded the Cambridge project, which gave it access to the technical blueprint that it eventually developed.

The computer became so successful that Lyons formed the LEO Computers, as a computer manufacturer and bureau service. In 1965, Byford started working there as a young programmer. He says: “I had no idea what a computer was, no idea what a programmer was. And my father spotted an advert in the Evening Standard for computer programmers or trainee computer programmers at Leo Computers. I thought that sounded interesting. So I applied and I got an interview where we had to do an aptitude test and write a program, which I think was for making a cup of tea or something. Daft, but it was a simple programme and you just had to do the logic.”

Recalling what it was like working at the computer bureau service for LEO Computers, he says: “You ended up working days and nights sometimes and you didn't get paid for working nights. You were there because you had something that needed to be programmed or a program needed to be run.”

One of the early programs Byford worked on was for a share index programme for Courtaulds, which was used at the time of ICI’s attempt to take-over the textile manufacturer. ICI bought a very large amount of Courtaulds shares. “The number of shares was so large that I couldn't calculate it in the program. I had to enter the actual dividend into the program code. You had to do things like that,” he says. Such limitations influenced the way software was developed as mainframe and centralised computing began to take off, which led to problems like the Y2K or millennium bug that was a result of coding dates as two, rather than four digits.

It may have saved a couple of bytes per date stored, but encoding two-digit dates, resulted in a significant reduction in the size of the data store when scaled up to the hundreds of thousands of records that these old computer systems needed to process, such as in a billing system for a utility.

The first proper run of LEO - the Lyons Electronic Office business computer - was made on November 30th, 1951 and this November marks the 75th anniversary of that run. This represents the first time in history that a computer was used to run a business process. The process in question was one to manage bakery valuation.

To celebrate this anniversary, the LEO Computer Society is organising a number of special events including one at the Centre for Computing History in Cambridge on Saturday 28th November, which will have staged recreations of Lyons teashops, celebrating LEO’s origins at J Lyons & Co. There is also a day of talks and LEO demos at The National Museum of Computing, Bletchley Park on Sunday 29th November and on Monday 30th November the LEO Computer Society is hosting an event at the Worshipful Company of IT, Farringdon, London, to commemorate the first computer program run on the LEO.