The Archaeology of Very Early Algorithms, 1948-58 - Christopher Strachey's Love Letter Generator

Speakers: David Link
Date: 12th March 2009
Time: 14.30 Room is open from 14.00 - meet up with society members
Location: Fellows Library of the Science Museum, Exhibition Road, London, SW7 2DD

About the seminar

This talk will describe early steps in the programming of the first computers, illustrated by some interesting examples.

David Link will present his reconstruction of the "loveletters" algorithm (1952) by Christopher Strachey together with his implementation of an emulator of the Ferranti Mark 1 and the project currently underway to build a functional replica of the machine. He will provide an overview of the software developed in this formative period of British computing, and discuss examples of the software he managed to locate.

In June 1948, a team led by Frederic Williams and Tom Kilburn built the first fully electronic, digital, stored-program and universal computer worldwide at the Electrical Engineering Department of Manchester University: the Manchester "baby" prototype. It was based on the first reliable means of volatile storage, the Williams tube. Max Newman and Alan Turing from the Mathematics Department played an important and still disputed role in the conception of the machine.

From 1949 to 1950, the computer was extended and modified on a daily basis, to become the "Manchester Mark 1". In 1951, the firm of Ferranti industrially produced an `engineered’ production version of it, the "Ferranti Mark 1", of which two were sold, one to Manchester University and one to Toronto University.

The machine was programmed in four-letter operation codes from the 5-bit Baudot alphabet, common in teleprinters and wartime cryptography. Soon, a number of conventions were created to make programming less cumbersome, using "Schemes" and "Autocodes".

It is estimated that already by 1953, some 50 scientists were employing the machine in their research. The main disciplines they were coming from were x-ray crystallography, molecular chemistry, meteorology, engineering, and nuclear physics.

When the Ferranti Mark 1 in Manchester was replaced in 1958, it was disassembled, and this is why only very few parts of the machine remain. Unfortunately, the situation is similar for the software developed for it. Despite intensive efforts, I could only unearth an alarmingly small fraction of these pioneering programmes. A part of British techno-cultural heritage of international importance is at stake.

About the Speakers

Dr David Link took his PhD in philosophy in 2005 at Humboldt-University, Berlin, with a thesis on text generating algorithms in the early years of computer development ("Poetry Machines / Machine Poetry"). He works as a theorist, artist and programmer. His current research focusses on the convergence of mathematics and engineering in the early 20th century. For further information see his website, and the article there titled “There must be an angel. On the beginnings of the arithmetics of rays“, in: Variantology 2 (2007).


The Digital 60 website has more about the Ferranti Mark 1 computer, and about programming on the Ferranti Mark 1 .

A brief profile of Christopher Strachey is in a recent issue of Resurrection.


Click to see a podcast of the event