Computer Conservation Society.


Bob Eager


2:30pm - Start of webinar and event
5:00pm - End


The Edinburgh Multi-Access System (EMAS) project started in 1966, and resulted in a real service to users from 1971, running on an ICL System 4/75. In 1976, work started on porting this to the ICL 2900 series, and a service was offered from October 1978. The University of Kent took up the system, and offered a service from late 1979. A further port was made to IBM and IBM clone systems, with the final service being closed in 1992.

EMAS was very efficient and reliable (arguably much more so than the manufacturer’s offerings). It was technically advanced in several ways, one example being the memory mapped file system.

The talk will cover the history of EMAS, and then look at some of the more interesting technical aspects of the system.

About the speaker

Bob Eager

I graduated in Electronics from the University of Kent in 1973, followed by a Master’s in Computer Studies at the University of Essex. I was then invited back to Kent to do research in the area of operating systems portability. In 1978 I was appointed as a lecturer, but rapidly seconded (for 50% of my time) to help evaluate the Edinburgh Multi-Access System as a replacement for the unreliable VME/K system.

I oversaw it for the next eight years, with some challenging technical issues along the way. Subsequently I managed the University's VAX cluster for six years before taking ten years as Master of Darwin College. I returned to become Director of Admissions for Computing until my retirement in 2015. Throughout this time I was teaching, mainly operating systems and compiling techniques.

In retirement, I have indulged my interest in historical computing, particularly in the areas of simulators and replicas. My most recent project was the resurrection of the Cambridge TRIPOS system on the PDP-11, from incomplete and internally incompatible pieces of source code. My long suffering wife allows me to keep a lot of ‘junk’ (her words) in the house, a shed, and a large storage unit.

Our events are for adults aged 16 years and over.

BCS is a membership organisation. If you enjoy this event, please consider joining BCS. You’ll be very welcome. You’ll receive access to many exclusive career development tools, an introduction to a thriving professional community and also help us Make IT Good For Society. Join BCS today.

For overseas delegates who wish to attend the event, please note that BCS does not issue invitation letters.


BCS is following government guidelines and we would ask attendees to continue to also follow these guidelines. Please go to for more information, advice, and instructions.

This event is brought to you by: Computer Conservation Society

Hybrid event: Edinburgh Multi Access System (EMAS)
Date and time
Thursday 17 November, 2:30pm - 5:00pm
BCS, The Chartered Institute for IT
25 Copthall Avenue
This event is sold out