Little Bits of History

Manchester Baby

Posted in History by patriciahysell on June 21, 2013
Manchester Baby

Manchester Baby

June 21, 1948: The Manchester Baby works. The Manchester Small-Scale Experimental Machine (SSEM), or The Baby, was produced at Victoria University of Manchester. It was the world’s first stored-program computer. Frederic C. Williams, Tom Kilburn, and Geoff Tootill fired up the machine and observed the effect. The machine was built to test the Williams Tube (also called the Williams-Kilburn Tube). The cathode ray tube stored 500-1,000 bits of binary data. There are 8 bits to a byte of data and 1,024 bytes in one kilobyte (KB). There are 8,589,934,592 bits in a gigabyte (GB), our normal measurement for storing information today.

The Small Scale machine took up a whole wall of space. It was not built as a functional computer, but only to test the viability of the tube design. There were three programs written for The Baby. The first one was to find the highest proper factor of 218. It took 17 instructions to get to the answer. Baby took 52 minutes and performed 3.5 million operations before arriving at the solution. The device led to the development of the Manchester Mark 1 which in turn directly led to the Ferranti Mark 1, the first commercially available general computer.

Professor Sir F. C. Williams, educated at the University of Manchester and Oxford University, was interested in engineering and worked with electronics. He visited the US and worked with scientists on the ENIAC project. That early computer used cathode ray tubes, but could not store programs. A rebuild of the hardware, sometimes taking days of work, was needed to change the program. Sir Williams concentrated on designing a tube capable of storing data. He returned to Manchester and he and Kilburn developed a tube able to store data over a period of hours, using standard equipment, and housed in a room without harsh temperature restrictions.

Tom Kilburn, a 25-year-old inexperienced scholar, first met Williams during World War II. Kilburn was working with the Telecommunications Research Establishment when he was assigned to work with the older man. After the war, the two continued to work together and finally they developed a specialized tube. They built the SSEM to prove the efficacy and Kilburn wrote the program for the first test. He went on to work with others in creating ever-improved devices leading us into the future – the Age of the Computer.

“… the most exciting time was June 1948 when the first machine worked. Without question. Nothing could ever compare with that.” – Tom Kilburn

“Never let a computer know you’re in a hurry.” – adage

“Computers, huh? I’ve heard it all boils down to just a bunch of ones and zeroes…. I don’t know how that enables me to see naked women, but however it works, God bless you guys.” – Doug Heffernan

“Don’t explain computers to laymen. Simpler to explain sex to a virgin.” – Robert A. Heinlein

This article first appeared at in 2009. Editor’s update: The Ferranti Mark 1 debuted in February 1951 at the University of Manchester, a month ahead of UNIVAC I arriving at the US Census Bureau. The main improvements of the Mark 1 over its predecessor were the size of the primary and secondary storage as well as a faster multiplier. It also could carry additional instructions. It used a 20-bit word stored as a single line of dots. As electric charges fell to the surface of the Williams tube display, each cathode tube stored 64 rows of dots. Instructions were stored as one word and numbers were stored as two words. Other tubes stored others pieces to the puzzle, including accumulators and registers. There were 4,050 vacuum tubes for the multiplier alone, which was about a quarter of the total number of tubes.

Also on this day: Job Insecurity – In 1919, the Winnipeg Strike goes horribly wrong.
SpaceShipOne – In 2004, the first privately funded ship makes it into space.
Long – In 1948, the first LP album was demonstrated.