1970 - 1979

The History of Computer Science 1970 - 1979


The KDF9 computer is retired from service and replaced by an ICL 1906A installed in a new specially-designed building in Elms Road.

The Service Division of the Computer Centre was greatly expanded in size and moved into the new building, while the Academic Division (responsible for all computer science teaching and research) remained in the Aston-Webb Building and adjacent "temporary" huts. This physical separation of the Academic and Service Divisions of the Computer Centre led inevitably to a sharper separation in their roles. The Academic Division began to function more and more as any other academic department in the Faculty of Science and Engineering (and the University moved gradually to funding it in this way also). However, computer science teaching and research was still totally dependent upon the Service Division for all computing facilities (in 1972 the Academic Division had no computing equipment of its own).


The BSc course in Mathematics and Computer Science is established and has its first intake of students. This course is one stream within the integrated range of courses offered by the School of Mathematical Sciences, all sharing a common first year and diverging in second and third years.


A Modular One minicomputer is purchased for computer science research and specialist teaching.

The Modular One was the first computer purchased solely for computer science use, instead of providing a computing service to all University departments. It was funded by an equipment grant from the Faculty of Science and Engineering, whereas the computing service was funded mainly by the Computer Board. The main uses of the Modular One were for research in programming languages and operating systems, and for MSc projects. The main programming language used for this work was BCPL.

The Modular One configuration installed in 1973 included 16K words of main memory (16 bits/word, 0.75 microsecond cycle time), 1M word fixed-head disk (17 ms average access, 7 microseconds/word transfer rate), paper tape reader (1000 c/s), paper tape punch (120 c/s), and a multiplexer for 8 lines (for local teletype terminals). The cost was £23,000 after various discounts. The memory was upgraded to 24K in April 1974. The Modular One suffered from poor hardware reliability, typically having three or four major faults per year. One particular disk fault caused the machine to be out of action for over two months while the engineers tried to diagnose the fault!

The Modular One Minicomputer in 1976
The Modular One Minicomputer in 1976
(People, from left to right: Jacob Adeniyi,
unknown, Brent Holden, Harold Sach)


The Computer Centre is renamed the Centre for Computing and Computer Science.

Despite Stuart Hollingdale's recommendation that the Academic Division should be split off as an independent Department of Computer Science, the University decided against this and, after Hollingdale's retirement in 1974, advertised for the single post of Director of the Computer Centre and Professor of Computing. Peter Jarratt was appointed to this post in 1975.

The 1970s were a time of poor industrial relations generally and the University was not exempt from these problems. The operators for the University's 1906A computer went on strike for several months during the Autumn Term of 1976 and the Spring Term of 1977. This put the 1906A out of action completely and severely disrupted Computer Science teaching as the 1906A was used for practical work for nearly all programming courses. As an emergency replacement a Prime minicomputer was temporarily installed in the old KDF9 Room for the duration of the strike. It was used solely to provide computing facilities for practical programming courses that would otherwise have been unable to continue.


The BSc course in Computer Science and Electronic Engineering is established and has its first intake of students.


A Digital Equipment DEC2050 computer is installed to supplement the 1906A in the Service Division of the Centre for Computing and Computer Science.

The DEC20 (as it was generally called) was capable of handling 80 on-line terminals simultaneously and was intended to provide on-line computing facilities to supplement the 1906A which was primarily used for batch processing. This machine was located in the Aston-Webb Building (C Block) and did not require the continuous presence of operators (hence was hoped to be immune to the strike action that had recently crippled the 1906A). Terminal rooms were set up in the Aston-Webb Building by the Computing Service and smaller clusters of terminals were located throughout the University for researchers.

The DEC2050 was used heavily for teaching of programming. It was the first computer in the University capable of supporting a reasonably large number of students working at on-line terminals. Previously, most teaching had been done using batch processing for practical programming work; i.e. students wrote programs out on special forms which were then punched onto cards before being input to the computer. Students were lucky to get much more than one run per day using batch processing. The new on-line terminals to the DEC20 were hugely attractive to students as they could now enter their programs on-line, run them and get the results back almost instantly.

Demand was such that saturation was reached very quickly, even after a substantial upgrade to the configuration (which converted it to a DEC2060) only a year after installation.


A Digital Equipment PDP11/34 running UNIX is installed in the Academic Division of the Centre for Computing and Computer Science for research and teaching, to replace the Modular One.

The PDP11/34 configuration installed in July 1979 included 64K words main memory (16 bits/word), two 5MB exchangeable disks, and a multiplexer for 8 lines (9600 baud). Peripheral devices included a printer (180 c/s), cartridge tape unit, and VDU terminals. The following year the memory was upgraded to 128K words and an additional 8-line multiplexer was added. Two years later a 134MB fixed disk was added.