THE last surviving designer of the world's oldest working computer has died, aged 98.

Richard 'Dick' Barnes was one of the three pioneers behind the world-famous Harwell Dekatron at the Atomic Energy Research Establishment (AERE).

Mr Barnes was also an active member of St Nicolas' Church in Abingdon and a skilled amateur historian.

Dick Barnes was born on October 22, 1920 in Plymouth.

He went to school in Basingstoke, but had his university degree interrupted by the Second World War.

Mr Barnes worked on radar research in the Air Ministry at Swanage, before the unit moved to Malvern when the Luftwaffe started attacking radar stations on the south coast.

He was a platoon commander in the Home Guard and later learnt to fly Tiger Moth biplanes.

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After the war, Mr Barnes continued at AERE at Malvern, where one extra-curricular activity was managing amateur dramatics productions.

There, he met Doreen Hoyle, a draughtswoman at the Telecommunications Research Establishment (TRE).

The couple followed AERE to Harwell and married in 1949, living in Didcot, Wantage and finally Abingdon, where they moved in 1951.

That period was significant for Mr Barnes, who started working on the Harwell Dekatron with colleagues Ted Cooke-Yarborough and Gurney Thomas in 1949.

The computer was first used in 1951, the same year as Mr Barnes's daughter, Rosalind, was born, with his son, Adrian, following three years later.

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At the time, Mr Barnes called the Dekatron 'a prize piece of working scrap', but the computer supported the world's first commercial nuclear reactor at Calder Hall, Cumbria.

In 1956, he helped produce the Harwell Transistor Computer (CADET), which may have been the first fully transistorised, or second generation, computer in the world, cementing Mr Barnes's place as an early computer pioneer.

He worked at AERE until retirement, but still left a mark outside his career.

Mr and Mrs Barnes were active members of St Nicolas' Church for more than 60 years, starting from the 1950s. The former spent 16 years as churchwarden, and led morning prayer for 15 years.

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In 1972, Mr Barnes launched the Drayton village newspaper, the Drayton Chronicle, and was also secretary of the Friends of Abingdon group and active in the Abingdon Archaeological and Historical Society (AAAHS).

He often presented to the local history group and received the Judith Hunter Prize of the Berkshire Local History Association in 2006.

When volunteers began reassembling the Dekatron at Bletchley Park in 2009, Mr Barnes took great interest, even finding boxes of his own paperwork from decades earlier. The machine was switched back on in 2012.

In 2017, he received the British Empire Medal in the New Year Honours for services to the church and community in Abingdon.

Mr Barnes died in Abingdon on April 8 and is survived by his wife, daughter and son.

A memorial service will be held at St Helen’s Church, Abingdon, on June 4 at 11am.