DONALD DAVIES
Donald Watts Davies was born in Treorchy in the Rhondda Valley. His father, a
clerk at a coalmine, died a few months later, and his mother took Donald and his
twin sister back to her home town of Portsmouth, where he went to school.
At Imperial College, London, he gained BSc degrees in physics in 1943 and
mathematics in 1947, both with first class honours; he was awarded the Lubbock
Memorial Prize as the leading mathematician of his year at London University in
1947. In between the two degrees he worked at Birmingham University on atomic
research as an assistant to Klaus Fuchs, and at ICI Billingham.
During his last year at university he attended a lecture by John Womersley,
superintendent of the mathematics division of the National Physical Laboratory (NPL),
about the ACE digital computer which was being developed there. Excited by the
potential of the new technology, he immediately applied to join the group, and
in September 1947 he joined the laboratory as a member of the small team, which
was led by Alan Turing of Bletchley Park fame.
The group's work, based on Turing's design, eventually led to the Pilot ACE
computer, which ran its first program on May 10, 1950; it was one of the first
four or five electronic stored-program digital computers in the world, and
certainly the first in London. Along with Ted Newman, Jim Wilkinson and others,
Davies had played an important part in the detailed design and development of
the machine, and its successor, the full-scale ACE.
As computer development moved from the laboratory to industry, Davies's
interests widened to include the purposes for which computers could be used. For
example, he developed a road traffic simulator, and in 1958 he initiated a
project to use a computer to translate technical Russian into English.
In 1963 he was appointed technical manager of the advanced computer techniques
project, responsible for government support for the British computer industry.
His combination of managerial skills with technical ability led to rapid
progress through the grades of the scientific Civil Service, and in 1966 he
succeeded Albert Uttley as superintendent of NPL's autonomics division. He soon
turned this into a division of computer science, giving it new and more
practical objectives.
The key new project was the development of an idea he had originated in 1965:
that to achieve communication between computers a fast message-switching
communication service was needed, in which long messages were split into chunks
sent separately so as to minimise the risk of congestion. The chunks he called
packets, and the technique became known as packet-switching.
His network design was received enthusiastically by America's Advanced Research
Project Agency (ARPA), and the Arpanet and the NPL local network became the
first two computer networks in the world using the technique. Today's Internet
can be traced back directly to this origin.
In 1979 Davies was able to relinquish his managerial post at NPL to concentrate
on technical work. Realising that computer networks would be used widely only if
malicious interference could be prevented, he started a group to work on data
security, concentrating on the new method of public key cryptosystems. The group
built a strong consultancy role round his expertise; all the major British
clearing banks, for instance, used its services. He retired in 1984 and
continued his work as a data security consultant.
Donald Davies married Diane Burton in 1955; she survives him, along with their
daughter and two sons.
Donald Watts Davies was born in Treorchy in the Rhondda Valley. His father, a
clerk at a coalmine, died a few months later, and his mother took Donald and his
twin sister back to her home town of Portsmouth, where he went to school.
At Imperial College, London, he gained BSc degrees in physics in 1943 and
mathematics in 1947, both with first class honours; he was awarded the Lubbock
Memorial Prize as the leading mathematician of his year at London University in
1947. In between the two degrees he worked at Birmingham University on atomic
research as an assistant to Klaus Fuchs, and at ICI Billingham.
During his last year at university he attended a lecture by John Womersley,
superintendent of the mathematics division of the National Physical Laboratory (NPL),
about the ACE digital computer which was being developed there. Excited by the
potential of the new technology, he immediately applied to join the group, and
in September 1947 he joined the laboratory as a member of the small team, which
was led by Alan Turing of Bletchley Park fame.
The group's work, based on Turing's design, eventually led to the Pilot ACE
computer, which ran its first program on May 10, 1950; it was one of the first
four or five electronic stored-program digital computers in the world, and
certainly the first in London. Along with Ted Newman, Jim Wilkinson and others,
Davies had played an important part in the detailed design and development of
the machine, and its successor, the full-scale ACE.
As computer development moved from the laboratory to industry, Davies's
interests widened to include the purposes for which computers could be used. For
example, he developed a road traffic simulator, and in 1958 he initiated a
project to use a computer to translate technical Russian into English.
In 1963 he was appointed technical manager of the advanced computer techniques
project, responsible for government support for the British computer industry.
His combination of managerial skills with technical ability led to rapid
progress through the grades of the scientific Civil Service, and in 1966 he
succeeded Albert Uttley as superintendent of NPL's autonomics division. He soon
turned this into a division of computer science, giving it new and more
practical objectives.
The key new project was the development of an idea he had originated in 1965:
that to achieve communication between computers a fast message-switching
communication service was needed, in which long messages were split into chunks
sent separately so as to minimise the risk of congestion. The chunks he called
packets, and the technique became known as packet-switching.
His network design was received enthusiastically by America's Advanced Research
Project Agency (ARPA), and the Arpanet and the NPL local network became the
first two computer networks in the world using the technique. Today's Internet
can be traced back directly to this origin.
In 1979 Davies was able to relinquish his managerial post at NPL to concentrate
on technical work. Realising that computer networks would be used widely only if
malicious interference could be prevented, he started a group to work on data
security, concentrating on the new method of public key cryptosystems. The group
built a strong consultancy role round his expertise; all the major British
clearing banks, for instance, used its services. He retired in 1984 and
continued his work as a data security consultant.
Donald Davies married Diane Burton in 1955; she survives him, along with their
daughter and two sons.