Dai Edwards obituary

My colleague Dai Edwards, who has died aged 92, was one of a small group of engineers who designed the world’s first commercially available computer. He went on to help design other high-performance computers, each the product of fruitful collaboration between academia and industry.

David Beverley George Edwards, known to colleagues as Dai, was born in Tonteg, South Wales. He was the only child of Cecilia (nee George) and William Edwards, who were both teachers. Dai went to Pontypridd boys’ intermediate school, leaving in 1945 with a state scholarship to study physics at Manchester University. Upon graduation, he joined Professor FC (Freddie) Williams’ electrical engineering group in September 1948.

Dai was one of three research students who worked with Williams, Tom Kilburn and Geoff Tootill on enhancing the capabilities of a small computer, known as Baby, which had first run a program on 21 June 1948. By April 1949 this team had produced the Manchester Mark I, which was used by Alan Turing and others for the investigation of mathematical problems. Dai’s particular responsibility was the design of a novel set of fast modifier registers for this computer.

The government placed a contract with the local company Ferranti to produce a fully engineered production version of the university’s 1949 machine. The result was the Ferranti Mark I computer, first delivered on 12 February 1951. Dai was closely involved in the transfer of technology from academia to industry.

Dai continued as a key member of Kilburn’s research group, building prototypes of high-performance computers required for scientific applications during the cold war.

In 1950 Dai became a consultant to Ferranti and remained in this position for the next 22 years, latterly with ICT and ICL, the successors to Ferranti.

During this time, the Ferranti Mercury computer and the Ferranti Atlas computer were produced, each derived from university prototypes. Among Dai’s many patents, he was a co-inventor with Kilburn and Frank Sumner of the Atlas Virtual Memory system.

In 1965 the University of Manchester admitted its first computer science undergraduates. Dai took charge of setting up the laboratories for this course. In 1966 he was appointed professor of computer engineering, a position funded by ICL to mark the many fruitful collaborations between the company and the university. He retired in 1988.

Dai married Betty Duckworth, a teacher, in 1953, and they had three children. Betty died of cancer in 1977. Two years later he married Jane Ellis, a doctor, and they, too, had three children. Dai is survived by Jane and his children, Ann, Huw, Keith, Helen, Carol and Joy, eight grandchildren and 12 great-grandchildren.