Technical documents relating to KDF9 – an early British computer designed and built by English Electric

Designed by English Electric, the KDF9 computer first came into service in 1964, with the last model being decommissioned in 1980 at the National Physical Laboratory. The KDF9 was one of the earliest fully hardware-secured multiprogramming systems; up to four programs could be run simultaneously under the control of its Timesharing Director operating system. The collection comprises reports, notes, figure drawings and specifications for the KDF9 computer.