Alexander Douglas

If you do something once, people will call it an accident. If you do it twice, they call it a coincidence. But do it a third time and you’ve just proven a natural law.
Grace Hopper

EDSAC computer
The Electronic Delay Storage Automatic Calculator (EDSAC) computer

In 1952 Alexander Shafto Douglas (1921–2010), known as “Sandy”, a graduate student at Cambridge, was writing his Ph.D. thesis on human-computer interaction for the University of Cambridge. He decided as part of his thesis to create a computer game on the EDSAC computer at University (one of the first stored-program computers in the world), thus creating the first graphical computer game OXO (also known as Noughts and Crosses, an old non-computer game that people can play with pen and paper).

Electronic Delay Storage Automatic Calculator (EDSAC) was a unique early (built in 1948) vacuum tube (it contained 3000 tubes) based British computer, operating 600 instructions per second. It used 32 mercury delay lines (or long tanks) each of which stored 32 words of 18 bits. Hence the total memory capacity of the EDSAC was the equivalent of about 2 kilobytes. A useful feature of this serial memory technology was that it was possible to display the contents of the store on Cathode Ray Tube (CRT) monitors. Each tank stored 16 words of 35 bits. EDSAC used three CRTs, one of which displayed the contents of one of the long tanks. Thus, the display was a matrix of 35×16 dots.

An OXO game simulator for MAC
An OXO game simulator for MAC

The input of EDSAC was via five-hole punched tape (thus the actual program for the OXO game was punched on a strip of paper, and used an assembler language) and the output was via a teleprinter or CRT. Debuggers still didn’t exist, but a CRT screen could be set to display the contents of a particular piece of memory. This was used to see whether a number was converging, for example. A loudspeaker was connected to the accumulator’s sign bit; experienced users knew healthy and unhealthy sounds of programs, particularly programs “hung” in a loop.

To play the OXO game (see the OXO game simulator nearby), the player would enter input (where he wanted to place his naught or cross) using a rotary telephone controller, and output was displayed on the computer’s dot matrix cathode ray tube. Each game was played against an artificially intelligent opponent (EDSAC) and the player determined who played first (EDSAC or USER).

The text output of the OXO game was something like this:

6 5 4 BY
3 2 1 A S DOUGLAS, C.1952




Alexander Douglas’ thesis was a success, earning him his Ph.D. and starting his career in science, however, he would never again program another video or computer game.

Biography of Alexander Douglas

Alexander Douglas (1921 – 2010)
Alexander Shafto Douglas (1921 – 2010)

Alexander “Sandy” Shafto Douglas was born on 21 May 1921 in London. At age eight, his family moved to Cromwell Road, near what would become the London Air Terminal.

In the winter of 1938–39, Douglas and his future wife Andrey Parker made a snowman on the grounds of the Natural History Museum. Douglas and his wife would go on to have two children, and at least two grandsons.

In 1940-1945 Douglas took part in the WWII in Home Guard Unit, and later in the Corps of Royal Engineers. After the war, he entered the University of Cambridge, where he earned his Ph.D. in 1953. From 1953 to 1957 he was engaged as a Prize Fellow of Trinity College, Cambridge. From 1957 to 1960 he set up the Computer Laboratory of the University of Leeds, and it was there that he first became interested in the application of computers to business problems. In 1960 Douglas entered the commercial field as Technical Director of the UK subsidiary of C-E-I-R (now Scientific Control Systems). In 1968 he left CEIR to initiate the European software interests of Leasco Systems and Research Ltd. as chairman. Later he has been a consultant to various agencies of the United Nations, including the Office of Science and Technology the Human Rights Commission, the Statistical Office of the U.N., and UNESCO. He has acted as a consultant also for several international companies including Shell, Philips, and ICI.

Alexander Douglas published over 60 papers and books covering topics in Atomic Physics, Crystallography, Solution of Differential Equations, Computer Design, Programming, and Operational Research in Shipbuilding, Oil Chemical Mining, Engineering, and Transportation Industries, and in the Printing Industry.

Alexander Douglas died in his sleep on 29 April 2010, from pneumonia.