Mind, Body, World- Foundations of Cognitive Science, 2013a

derived, in the same way as new knowledge is arrived at in the proofs discovered by
logicians and mathematicians (Davis & Hersh, 1981).
The abstract theories that describe physical symbol systems were not developed
into working artifacts until nearly the midpoint of the twentieth century. “Our
deepest insights into information processing were achieved in the thirties, before
modern computers came into being. It is a tribute to the genius of Alan Turing”
(Newell & Simon, 1976, p. 117). The first digital computer was the Z3, invented in
Germany in 1941 by Konrad Zuse (1993). In the United States, the earliest computers
were University of Pennsylvania’s ENIAC (created 1943–1946) and EDVAC
(created 1945–1950), Harvard’s MARK I (created 1944), and Princeton’s IAS or von
Neumann computer (created 1946–1951) (Burks, 2002; Cohen, 1999). The earliest
British computer was University of Manchester’s “Baby,” the small-scale experimental
machine (SSEM) that was first activated in June, 1948 (Lavington, 1980).
Although specific details vary from machine to machine, all digital computers
share three general characteristics (von Neumann, 1958). First, they have a memory
for the storage of symbolic structures. In what is now known as the von Neumann
architecture, this is a random access memory (RAM) in which any memory location
can be immediately accessed—without having to scroll through other locations, as
in a Turing machine—by using the memory’s address. Second, they have a mechanism
separate from memory that is responsible for the operations that manipulate
stored symbolic structures. Third, they have a controller for determining which
operation to perform at any given time. In the von Neumann architecture, the control
mechanism imposes serial processing, because only one operation will be performed
at a time.
Perhaps the earliest example of serial control is the nineteenth-century
punched cards used to govern the patterns in silk that were woven by Joseph Marie
Jacquard’s loom (Essinger, 2004). During weaving, at each pass of the loom’s shuttle,
holes in a card permitted some thread-controlling rods to be moved. When a rod
moved, the thread that it controlled was raised; this caused the thread to be visible
in that row of the pattern. A sequence of cards was created by tying cards together
end to end. When this “chain” was advanced to the next card, the rods would be
altered to create the appropriate appearance for the silk pattern’s next row.
The use of punched 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 punched 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 punched cards. Their potential for being applied to computing devices in general
was recognized by computer pioneer Charles Babbage, who was inspired by
Jacquard’s invention (Essinger, 2004).
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