©JSR 2011 General Computing Facilities at the University of Aberdeen, 1960 – 1996 Dr John S. Reid Hon. Curator of the Natural Philosophy Collection of Historical Scientific Instruments Introduction What I really wanted to find was an account of how computing facilities had developed over the decades at the University of Aberdeen. I wanted to put into the local context many of the computer related artefacts we have in the University’s Collection of Historical Scientific Instruments. These are particularly relevant to the early decades of the subject and not to 21st century developments. I didn’t find what I was looking for. This is my effort to create what I wanted to see. It is, by and large, a chronology. All the embedded illustrations are of Aberdeen material. The account concentrates on technology and equipment, and relates the growth of services provided. It doesn’t say much about software and even less about the personalities involved. I suggest that chapter has to be written by someone ‘in the system’ and not a mere user such as myself, albeit one who experienced almost all of the events related here. Mechanical days I remember 1960 better than some other years. It was the year I came to the University of Aberdeen. There were no digital electronic computing facilities. Hand operated mechanical calculators were common on campus and numerical techniques using these were present in some student courses as well as in academic offices and laboratories. The first use of these in coursework was probably that introduced in the 1930s by the Professor of Natural Philosophy, John A. Carroll. In the 1930s Carroll had sought advice from L. J. Comrie, an ex-astronomer then Superintendant of the Nautical Almanac Office who had made a substantial reputation for compiling tables using mechanical calculators. Comrie had begun in this field using a Brunsviga machine and these machines were amongst those used in the Nautical Almanac Office. It is likely that the two different Brunsviga machines in the University’s historic scientific instrument collection are representative of the University’s first use of mechanical calculators in teaching and research. One came from the Department of Natural Philosophy, the other from the (now closed) Department of Statistics. Carroll’s experience did not just influence a few colleagues and advanced students. Carroll was an astronomer who was seconded to the Admiralty in 1942 as Assistant Director of Scientific Research at the Admiralty’s Scientific Research and Experiment Department. With Comrie’s successor, Donald Sadler, and Admiralty colleague John Todd they established the Admiralty Computing Service. In 1945 Carroll went on to propose successfully the establishment of the 1/28 ©JSR 2011 NPL Mathematics Division as a National Computing Centre. In a way he had followed Comrie’s career of astronomer turned promoter of machine-aided calculation. It was a career pattern that became very common as the century continued: astronomy research leading to a career in computing, only it became electronic computing as the century progressed. By 1960 mechanical calculators were well embedded in the University and there was at least one classroom of these, used by students of mathematics and statistics. Facit machines, able to perform addition, subtraction, multiplication and division by operating a side handle that was cranked at each step, were in the classroom and were common elsewhere. Examples of these are in the instrument collection. Not uncommon in groups where calculation was important were electrically operated mechanical calculators such as those of Midas, Friden, Marchand, Diehl and others. Most numerical work was done with slide-rules but for calculations that required accuracy, more than two or three significant figures or many steps, then a calculator was essential. With a calculator one could solve integral and differential equations numerically that didn’t reduce to standard forms whose analytic solutions one could look up in a formidable book of tables such as the ‘Handbook of Mathematical Functions’ by Abramowitz and Stegun. The preparation of such books was a tour de force of the mechanical calculator age but they now seem like steam engines in the days of hybrid-electric cars. The Elliott 803 The driving force behind the University acquiring a computer seems to have been David J Finney, Reader and Head of Statistics, and possibly the only FRS in the University at the time. The time was 1961. Finney proposed to the Senate that a committee be set up to explore the possibility of obtaining a large computer for the joint use of all four Scottish Universities, without prejudice to individual University’s purchasing their own smaller computers. He was clearly a man with a vision. This led to the ‘Scottish Universities Standing Committee on Interavailability of Computer Services’, about which nothing more was heard in Senate. However, before the year was up the Court had appointed Dr A. M. Murray as lecturer in charge of the Department of Electronic Computing in the University of Aberdeen to begin on 1st January 1962, and an Elliott 803B computer had been ordered at a cost of about £30,000. The new Department was deemed to be in the Faculty of Science. David Finney became chair of the Computer Committee that was formed in 1962 to have responsibility for the control and use of the computer. This committee had representatives, mostly professorial, from the Departments of Midwifery & Gynaecology, Engineering, Natural Philosophy, Chemistry, Social Medicine, Agriculture and Mathematics. There was clearly significant interdisciplinary interest in the new machine. The Elliott was installed in the ‘Statistics Building’ (now a part of the Meston Building) in a room about the size of three or four academic offices. It was reported working, though without yet all of its peripherals, in January 1962. Sandy Murray was a Natural Philosophy BSc and PhD graduate of Aberdeen whose work with Norman March at the University of Sheffield on quantum solid state problems became well known. In this work he cut his computing teeth on an English Electric Deuce, one of the 2/28 ©JSR 2011 UK’s pioneering computers of the 1950s. The Deuce was still selling in the early 1960s but it used over 1000 thermionic valves and, although lightning quick by mechanical calculator standards, was already being seen as ‘slow’. Sandy was influential in recommending the Elliott 803, a new breed of transistor-based computer with a well thought-out architecture. It was a good choice, for the Elliott 803 became the most popular computer in the UK. The manufacturers described the machine as “a small, medium-speed digital computer” whose “minimal installation requires only 400 sq. ft. altogether, and power consumption of about 3½ kilowatts”. Our 803B had the maximum 8K of store and a floating point unit. Programming was initially in the purely numeric machine code (Sandy Murray’s speciality) or Autocode, a slightly higher form of computer life that allowed one to give short names to locations (usually a single letter) and that used names like ‘CYCLE’, ‘JUMP’, ‘REPEAT’ and so on to describe commands. Input and output was with 5-hole paper tape, which Sandy Murray could read almost as quickly as plain text. Longer tapes were prepared on one of the two keyboard perforators, shorter tapes could be punched up on one of the teleprinters that produced a typed copy on paper of what was punched. All these noisy items were in a separate room from the computer. The teleprinters were also used to obtain a print-up of tape that the computer had punched and could be used for making very minor edits to tapes. Binary savvy readers will have worked out that 5- hole tape can only support 32 different characters, not even enough for all the letters of the alphabet and the ten digits. This apparent difficulty was circumvented by having reserved characters that determined whether the 5-hole code was to be 3/28 ©JSR 2011 interpreted in ‘letter-shift’ mode or ‘figure-shift’ mode. This created 55 possibilities over and above ‘blank’, allowing punctuation marks, ‘£.@, %’ and a few other symbols. The luxury of distinguishing upper and lower case letters didn’t exist but it was no great hardship since the teleprinters printed only in upper case. The 803 was equipped with a loudspeaker in the console and each command sent a short ‘blip’ to the speaker. The time taken by commands was measured in milliseconds. E.g. 0.576 ms for standard commands, 0.864 ms for floating point addition, 4.896 ms for floating point multiplication and a maximum of 9.792 ms for floating point division. Thus when a program ran using a range of commands there was a characteristic burbling from the speaker. If a programme had several different sections, a change in the characteristics of the burbling “indicates to the practised ear the progress of a computation”, as the makers put it. This was useful for error detecting. One could put stop commands into the program at specific places. Execution would stop on reaching the command and could be re-started by using the keyboard bar. In this way one could teach oneself to identify the characteristics of the burbling with progress through the program and, for example, identify quickly where the program had got into an indefinitely repeating loop. This, combined with machine code programming that was at times necessary to get the results in the most efficient and quickest way given the limited storage made the whole experience very much ‘seat of your pants’ computing. Some people found the experience challenging and invigorating; others like a former colleague who used the 803 in its early years said “this experience put me off computing for several years”.