"Fifty years ago this past June, the Manchester Mark I prototype computer, also known as "Baby", became operational. Baby was the first computer to store a program electronically, and was also the first computer to store instructions and data in the same memory. Because vacuum tube technology was too immature to store memory reliably, Baby was designed to test memory based on a cathode ray tube. Not much memory, mind you. Baby boasted a full 1K bits of memory, organized as 32 words (or lines) of 32 bits each.
"In celebration of the birth of the first stored program computer on June 21, 1948, the Department of Computer Science at the University of Manchester recently reconstructed Baby and ran a programming contest to write the most imaginative program for Baby."
The background section to "The Baby" web page concludes with:
"The first program to run successfully, on June 21st 1948, was to determine the highest factor of a number. The number chosen was quite small, but within days they had built up to trying the program on 218, and the correct answer was found in 52 minutes, involving about 2.1 million instructions with about 3= million store accesses.
"F.C. Williams later said of the first successful run: 'A program was laboriously inserted and the start switch pressed. Immediately the spots on the display tube entered a mad dance. In early trials it was a dance of death leading to no useful result, and what was even worse, without yielding any clue as to what was wrong. But one day it stopped, and there, shining brightly in the expected place, was the expected answer. It was a moment to remember. This was in June 1948, and nothing was ever the same again.'
"With the Baby proving both the effectiveness of the Williams Tube and the basic stored-program concept, work was immediately started, with increased manpower, to design and build a more realistic, usable, computer based on the Baby. This was achieved between late 1948 and late 1949, in two or three incremental stages, with the Manchester Mark 1. This in turn was used as the basis of the design of the world's first general-purpose commercial computer, the Ferranti Mark 1."
Also of interest may be these related links, all associated with the celebration of the 50th yr anniversary of the modern computer at the University of Manchester.
The Manchester Mark I http://www.computer50.org/mark1/MM1.html
"Great Events in World of Computing" (interesting to compare against the Master List of D.M.) http://www.computer.org/history/photos/toc.htm
firstname.lastname@example.org (David Galbraith)