LEO and its early attempt to use Magnetic Tape
The LEO design team attempted to use Magnetic Tape in its early design and worked with Standard Telephone and Cables to provide the required capability. Ernest Lenaerts reports in his diaries on the failure of the venture.
Below is the Standard Telephone and Cables own account of their collaboration with J. Lyons, the failure of the magnetic tape facility to meet LEO’s reliability standards, and STC’s own venture into building computers resulting in the launch of the STANTEC ZEBRA, an early stored program computer, which for a limited time was successfully exported. See:
http://www.stlqcc.org.uk/a-brief-history-of-stl/
The Early Years
Shortly after the end of the second world war STC had decided to re-establish research facilities. Until the middle of 1931 a laboratory which could be considered the forerunner of STL had been established within ITT operating in premises formerly occupied by the Royal Air Force on Hendon Aerodrome. This laboratory suffered the fate of many similar institutions following the depression.
The new facilities were to be established in an existing plastics and cable factory in Progress Way, Enfield as a temporary measure. The company was to be known as Standard Telecommunication Laboratories and the date of formation was 1st. December 1945.
Further on there is reference to the Leo collaboration:
Fortunately about this time STC became involved with J. Lyons in the development of LEO, (Lyons Electronic Office), a computer system for payrolls, bread delivery forecasts and similar work to release office staff for other operations. STC approached STL to design the preparation of data in a form suitable for computer operation, the input (decimal to binary conversion), the output (binary to decimal conversion) and the ultimate paper results. System design was by D.A.Weir and J.Rice backed up by E.P.G.Wright. Design of circuits, a high speed magnetic tape machine and the necessary equipment practice was dealt with by D.S.Ridler and his team. The equipment was installed for trials in Cadby Hall but, although the design proved entirely suitable, it was finally removed because the high speed gas filled counting device that was extensively used in the circuitry lacked the extremely high reliability required. The gas tube was the STL decatron.
Because of this computer experience the Transmission Division asked us to produce a system to reduce the work involved in filter design. A team consisting of J.Rice, P.W.S.Harrild and D.G.Hunter designed a computer called STEP 1 based on magnetic drum storage and the laboratory again developed the circuits and equipment. This was one of the first electronic stored programme computers to go into active service. Subsequently STC were approached by the Dutch PTT Research Laboratories (NSEM) for assistance in developing a new computer and asked STL to provide the expertise. In consequence J.Rice worked in conjunction with the PTT, who had the basic idea, to design the practical concept, later to be produced at Newport by STC, known as ZEBRA. STL also developed the required circuitry together with the magnetic drum storage system. For some years ZEBRA was the UK’s largest export – over twenty systems.