Computer 50

The University of Manchester Celebrates the Birth of the Modern Computer

Update of 26 July 2010: Dr Brian Napper, the author of these pages, sadly passed away in March 2009.
The Computer50 pages are now an archived record and are no longer being maintained. Links and email addresses in these pages date from the time of the event and may have changed.

For any queries about these pages or about the history of Computer Science at Manchester University please email

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 full-sized 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. It in turn was the basis of the first commercially available computer, the Ferranti Mark 1, the first machine off the production line being delivered in February 1951.

These pages tell the story of the Baby and the Mark 1, and give a record of the 50th anniversary celebrations for the Mark 1, and the machines that followed it.

The highlight of the 1998 Celebrations was the construction of a working replica of the Baby now on display at the Museum of Science and Industry in Manchester (see Galleries > 1830 Warehouse > Baby Computer).

You can see the latest major changes in the pages in the log -- latest entry 30th March 2005.

November 16th 1953 saw the first execution of a program by the "Transistor Computer" -- see the note by its builder, Dick Grimsdale.

The Mark 1 Story

The StoryIn particularPeopleOutside Manchester
SSEM, the "Baby"
Manchester Mark 1      
Ferranti Mark 1
Mark 1 Literature
Williams Tube
Display Tube
First Program
Using the Mark 1
Maths Dept. Input   
Picture Gallery
F.C. Williams      
Tom Kilburn
Alan Turing
Max Newman
Other People
Contemporary Computers
Moore School Course
Other Early History Sites

Some information on the set of four machines designed by Tom Kilburn's team following on from the Mark 1 machines, up to 1974, is given in the Virtual Museum of Manchester Computing. The Mark 1 and the next three machines were all turned into commercial machines; the fifth, MU5, made a major contribution to the design of the ICL VME2900 series. The biography of Tom effectively gives a summary of the story of the Mark 1 and his later machines.

You can also find out about Current Research in the School of Computer Science.

Tom Kilburn died on January 17th 2001. A Memorial Service was held on May 1st 2001.
A short summary of his achievements can be found here.
A CD-ROM produced for the Celebrations is available
Are you interested in helping to maintain and demonstrate the Replica Baby machine?

Obviously over time some of the more ephemeral material originally linked to in these pages has disappeared off the Web. Links to such material have been replaced by underlined text in black.

These pages have been written and prepared by Brian Napper.

Copyright The University of Manchester 1998, 1999, 2000, 2001, 2003, 2005, 2010