The Small-Scale Experimental Machine, known as SSEM, or the "Baby", was designed and built at the University of Manchester, and made its first successful run of a program on June 21st 1948. It was the first machine that had all the components now classically regarded as characteristic of the basic computer. Most importantly it was the first computer that could store not only data but any (short!) user program in electronic memory and process it at electronic speed.

From this Small-Scale Experimental Machine a more powerful machine was designed and built, the Manchester Mark 1, which by April 1949 was generally available for computation in scientific research in the University. With the integration of a high speed magnetic drum by the Autumn (the ancestor of today's disc) this was the first machine with a fast electronic and magnetic two-level store.

This machine in turn was the basis of the Ferranti Mark1, arguably the world's first commercially available general-purpose computer, with the first machine delivered in February 1951.

You can see a history of the Mark1 and a some information on the set of later machines designed in the Electrical Engineering Department and then the Department of Computer Science, up to 1975, elsewhere on these pages.

The University and City of Manchester celebrated the 50th Anniversary of the birth of the Baby in 1998. The main components of the University's celebrations and the project to rebuild the "Baby", are summarised below. The City of Manchester celebrated with "digital summer 98".