Development
Developed at the University of Manchester in England, it provided the medium on which the first electronically stored-memory program was implemented in the Manchester Small-Scale Experimental Machine (SSEM) computer, which first successfully ran a program on 21 June 1948. In fact, rather than the Williams tube memory being designed for the SSEM, the SSEM was a testbed to demonstrate the reliability of the memory. Tom Kilburn wrote a 17-line program to calculate the highest factor of 218. Tradition at the university has it that this was the only program Kilburn ever wrote.
The Williams tube tended to become unreliable with age, and most working installations had to be "tuned" by hand. By contrast, mercury delay line memory was slower and not truly random access, as the bits were presented serially, which complicated programming. Delay lines also needed hand tuning, but did not age as badly and enjoyed some success in early digital electronic computing despite its data rate, weight, cost, thermal and toxicity problems. However, the Manchester Mark 1, which used Williams tubes, was successfully commercialised as the Ferranti Mark 1. Some early computers in the USA also used the Williams tube, including the IAS machine (originally designed for Selectron tube memory), the UNIVAC 1103, Whirlwind, IBM 701, IBM 702 and the Standards Western Automatic Computer (SWAC). Williams tubes were also used in the Soviet Strela-1, in the Japan TAC (Tokyo Automatic Computer).
-
A Williams-Kilburn tube
-
Diagram of Williams tube memory from the 1947 patent
Read more about this topic: Williams Tube
Famous quotes containing the word development:
“I’ve always been impressed by the different paths babies take in their physical development on the way to walking. It’s rare to see a behavior that starts out with such wide natural variation, yet becomes so uniform after only a few months.”
—Lawrence Kutner (20th century)
“Information about child development enhances parents’ capacity to respond appropriately to their children. Informed parents are better equipped to problem-solve, more confident of their decisions, and more likely to respond sensitively to their children’s developmental needs.”
—L. P. Wandersman (20th century)
“The man, or the boy, in his development is psychologically deterred from incorporating serving characteristics by an easily observable fact: there are already people around who are clearly meant to serve and they are girls and women. To perform the activities these people are doing is to risk being, and being thought of, and thinking of oneself, as a woman. This has been made a terrifying prospect and has been made to constitute a major threat to masculine identity.”
—Jean Baker Miller (20th century)