Code: The Hidden Language of Computer Hardware and Software

by Petzold Charles

Although Samuel Morse notified the patent office in 1836 that he had invented a successful telegraph, it wasn’t until 1843 that he was able to persuade Congress to fund a public demonstration of the device. The historic day was May 24, 1844, when a telegraph line rigged between Washington, D.C., and Baltimore, Maryland, successfully carried the biblical message: “What hath God wrought!”

Bell Telephone Laboratories was for many years a place where smart people could work on just about anything that interested them. Some of them, fortunately, were interested in computers.

All that changed December 16, 1947, when two physicists at Bell Labs named John Bardeen (1908–1991) and Walter Brattain (1902–1987) wired a different type of amplifier. This new amplifier was constructed from a slab of germanium—an element known as a semiconductor—and a strip of gold foil. They demonstrated it to their boss, William Shockley (1910–1989), a week later. It was the first transistor, a device that some people have called the most important invention of the twentieth century.

This idea seems to have been proposed first by British physicist Geoffrey Dummer (born 1909) in a speech in May 1952. “I would like to take a peep into the future,” he said. With the advent of the transistor and the work in semiconductors generally, it seems now possible to envisage electronic equipment in a solid block with no connecting wires. The block may consist of layers of insulating, conducting, rectifying and amplifying materials, the electrical functions being connected directly by cutting out areas of the various layers.

In one sense, all digital computers are the same. If the hardware of one processor can do something another can’t, the other processor can do it in software; they all end up doing the same thing. This is one of the implications of Alan Turing’s 1937 paper on computability.