Technology: 1,300 vacuum tubes

MEMORY SIZE: 128 + 1024 40-digit words MEMORY TYPE: cathode ray tube, magnetic drum TECHNOLOGY: 1,300 vacuum tubes FLOOR SPACE: medium room PROJECT LEADERS: Frederick Williams and Tom Kilburn

1949 - Manchester Mark 1 The Manchester Mark I computer functioned as a complete system using the Williams tube for memory. This University machine became the prototype for Ferranti Corp.'s first computer. Manchester Mark 1 START OF PROJECT: 1947 COMPLETED: 1949 ADD TIME: 1. 8 microseconds INPUT/OUTPUT: paper tape, teleprinter, switches

The Ferranti Mark 1


Background

In 1948 the government's chief scientist initiated a government contract with Ferranti Ltd. to make a production version of the Mark 1 "to Professor Williams' specification". This was important because it established a link between the university and industry, and ensured that the power of the electronic computer would be available as quickly as possible around the U.K (and abroad).

The architecture was closely based on the Manchester Mark 1, which was effectively treated as the prototype for the commercial version. The main improvements (apart from improved engineering) were increased B-line, CRT, and magnetic drum stores, a much faster multiplier, and an increased range of instructions, for example many more B-line operations. The magnetic drum store and the multiplier were substantially redesigned.

The Ferranti Mark 1 was the world's first commercially available general-purpose computer. The first machine off the production line was delivered to the University in February 1951. It was replaced in 1958.