The use of punch cards turned the Jacquard loom into a kind of universal machine: one changed the pattern being produced not by changing the loom, but simply by loading it with a different set of punch cards. Thus not only did Jacquard invent a new loom, but he also invented the idea of using a program to control the actions of a machine. Jacquard’s program was, of course, a sequence of punch cards. The potential of such control being applied to computing devices in general was recognized by computer pioneer Charles Babbage, who was inspired by Jacquard’s invention (Essinger, 2004).
By the late 1950s it became conventional to load the program then known as the “short code” (von Neumann, 1958) -- into memory. This is called memory-stored control
; the first modern computer to use this type of control was Manchester’s “Baby” (Lavington, 1980). In Chapter 2 we saw an example of this type of control in the universal Turing machine, whose ticker tape memory holds both the data to be manipulated and the description of a special purpose Turing machine that will do the manipulating. The universal Turing machine uses the description to permit it to pretend to be the specific machine that is defined on its tape (Hodges, 1983).
- Essinger, J. (2004). Jacquard's Web: How A Hand Loom Led To The Birth Of The Information Age. Oxford ; New York: Oxford University Press.
- Hodges, A. (1983). Alan Turing: The Enigma Of Intelligence. London: Unwin Paperbacks.
- Lavington, S. H. (1980). Early British Computers: The Story of Vintage Computers and the People Who Built Them. Bedford, Mass.: Digital Press : sole distributor for the U.S.A. and Canada, Digital Equipment Corp.
- von Neumann, J. (1958). The Computer And The Brain. New Haven, CN: Yale University Press.
(Added September 2010)