Logic door from Ferranti Mark I computer

Logic door from Ferranti Mark I computer, made by Ferranti Ltd, Moston, for the University of Manchester, c. 1950.

This is one of the last surviving parts of the world’s first commercially produced stored-program computer, the 1951 Ferranti Mark 1.

Built at Ferranti’s factory in Moston, the Ferranti Mark 1 was based on an improved version of the 'Baby computer developed at the University of Manchester. Unlike the experimental Baby, the Ferranti Mark 1 was neatly engineered for sale. Complex components were built into logic doors, making the computer tidy and easy to repair. Although it had a small fraction of the power of today’s computers, the main part of the Ferranti Mark 1 was so large it filled a whole room.

The first Ferranti Mark 1 was delivered in February 1951 to the University of Manchester. It was used largely for scientific research and engineering calculations, but also light-hearted pursuits, including some of the world’s first video games. It was decommissioned in 1958 and replaced by a faster computer. Ferranti sold a total of two Mark 1 computers and seven improved Mark 1* versions.