Analytical Engine: the Orig- Inal Computer
Chapter 2 Analytical Engine: The Orig- inal Computer As we learned in the fourth grade science course, back in 1801, a French man, Joseph Marie Jacquard, invented a power loom that could weave textiles, which had been done for a long time by hand. More interestingly, this machine can weave tex- tiles with patterns such as brocade, damask, and matelasse by controlling the operation with punched wooden cards, held together in a long row by rope. 1 How do these cards work? Each wooden card comes with punched holes, each row of which corresponds to one row of the design. In each position, if the needle needs to go through, there is a hole; other- wise, there is no hole. Multiple rows of holes are punched on each card and all the cards that compose the design of the textile are hooked together in order. 2 What do we get? With the control of such cards, needs go back and forth, moving from left to the right, row by row, and come up with something like the following: Although the punched card concept was based on some even earlier invention by Basile Bou- chon around 1725, “the Jacquard loom was the first machine to use punch cards to con- trol a sequence of operations”. Let’s check out a little demo as how Jacquard’s machine worked. 3 Why do we talk about a loom? With Jacquard loom, if you want to switch to a different pattern, you simply change the punched cards. By the same token, with a modern computer, if you want it to run a different application, you simply load it with a different program, which used to keep on a deck of paper based punched cards.
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