Telephone relays
When I was born, in 1938, there were no computers. The word “computer” meant a person who used a calculator. I don’t know why computers did not exist then. The seeds had been planted well before. The first general-purpose computer was designed in 1837 by Charles Babbage. He planned to build it, but was not able to get funding. In any case his computer really was not practical given the technology of his day, gears and levers. His machine would have been the size of a room, driven by a steam engine, very slow, and terribly expensive to build.
Ada Countess Lovelace, Lord Byron’s daughter, worked with Babbage to document his machine. She is often called the first programmer. She was the first person to see the potential of computers to do more than arithmetic. She foresaw that computers could, for example, write music. However, there is no evidence that the work of Babbage or of Ada Lovelace had much impact on the world. Apparently most of the twentieth century computer pioneers did not know of them.
The second person to design a general purpose computer had a profound impact on the world. Alan Turing, who started out as a pure mathematician, made major contributions to our understanding of computers and to the field of artificial intelligence as well as being instrumental in breaking German encrypted messages during World War II. After the war Winston Churchill said that Turing’s work was the greatest single contribution to victory in the Second World War.
In 1936, the year my parents married, Turing published a paper in which he answered a question in theoretical mathematics called the Entscheidungsproblem. In doing so he invented a computer, although he did not call it that. This machine is completely impractical and he never intended that it be built, but in proving that his machine can compute any computable mathematical function, Turing gave us an unequivocal definition of what it means to call a computer “general purpose.” It is easy to show whether any given real computer can imitate a Turing machine. If it can, it is called “Turing complete.” Any Turing complete computer can do anything any other computer can do. All present-day computers are Turing complete. My smartphone can do anything an IBM mainframe computer can do. Except for limitations in memory size and attachments, so can my microwave oven.
Babbage’s computer was Turing-complete, but none of the several computers built during my early childhood were. The first computer that was Turing-complete in practice did not come along until 1946 (the ENIAC) when I was eight.
Work on the first computer ever built started in 1938, my birth year, and was completed at Bell Labs in New York in 1939. It was the brainchild of George Stibitz, a Bell Labs engineer.
As a hobby Stibitz took home some surplus telephone relays (electrically operated switches used in dial telephone switching equipment). He played with these, discovering how to use them to construct the building bones of a computer. When his boss heard about this he asked Stibitz to build a computer to be used in designing telephone systems, the Bell Labs Relay Computer #1. It was not a general purpose computer, really more like a very elaborate calculator for dealing with complex arithmetic, but the techniques it incorporated were applicable to more capable computers and led to four more machines at Bell Labs.
All the technology used in early machines had existed before 1920. Dial telephones, which had been in major cities for years, came to my home town when I was eight. I remember being fascinated by our new telephone with its dial. The ‘phone was installed before the switching system was operational, so we still had to wait for an operator. Since the telephone company was letting the operators retire or transfer to other jobs in preparation for the new system. the wait for an operator to answer the phone got longer and longer. One day, waiting for the operator, I could not resist the new dial, so I dialed ‘0’ for ‘Operator.” Apparently the operator came on the line just as I dialed, and the sound of the dial pulses in her headphones were painfully loud. “Don’t EVER do that again!” she scolded.
The early machines were quite expensive. Except for the first Bell Labs machine, all early computers were built as part of the war effort (World War II). Perhaps that is why computers were not built until I was born.
– Rudd Canaday (ruddcanaday.com)
– Start of blog: My adventures in software
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