Saint George's Operating System

One of the UK’s great workhorses of computing, the ICL 1900 series is now just a distant hum in the background, but its operating system, GEORGE, lives on in many people’s memories and should be celebrated today, St George’s Day!

The Dragon that GEORGE was protecting us from was the hardware – a developing series of machines that grew and grew taking advantage of improvements in technology.

The design of the 1900 itself dates back to a Ferranti paper exercise developed by Harry Johnson and hence often known as the HARRIAC. This design wasn’t used at the time and was passed to Ferranti-Packard in Canada who developed their FP6000 series. The design of the FP6000 later came back to the UK as the basis for the 1900 machines.  ICL demonstrated their first two 1900 computers at the Business Efficiency show in Olympia in 1965 and deliveries started in earnest in May 1965.

Rising above all the hardware was the operating system known as GEORGE or GENeral ORGanisational Environment. Developed by a team lead by George Felton in Stevenage, the system name was a actually a tribute to George himself.  GEORGE would provide a consistent and reliable front-end to the developing machines.

Government support for ICL meant that nearly all UK nationalised companies and very many universities used 1900 machines throughout the 1960s and 70s.

I well remember under-graduate computing in the early 1980s when a deck of punched cards would be passed to the computer centre reception ladies. These guardians, not to say dragons, of the university’s 1904S would take our meagre offerings and add them to the job queue. Throughout the rest of the day the job list would be printed and pinned up next to reception – a list more than 2m long by the end of the day.

Of course, the low priority jobs from us under-grads would get pushed further and further down the queue, until just before midnight the job would be run. Typically GEORGE would take one look at the control cards, run it past the compiler, and then spit out two or three pages of errors!

Calling in at the computer centre, typically on the way back from the pub, I could grab a quick look at the error report and attempt to punch a few replacement cards. Submitting the job at that time of night meant it might get another run before morning!

ICL sold 1900 based systems until almost the 1980s, but GEORGE still lived on in the ICL New Range machines – the 2900 series. You can follow TNMOC’s restoration of an ICL 2966 by clicking here.

Finally, readers of this blog might like to know that they can get even closer to TNMOC, by joining as a member. There is more information here.