1939 AD to 1944 AD |
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| Many consider that the modern computer era commenced with the
first large-scale automatic digital computer, which was developed between 1939 and 1944
(see also Konrad Zuse and his Z3 computer). This device, the brainchild of a Harvard graduate, Howard H. Aiken, was officially known as the IBM automatic sequence controlled calculator (ASCC), but is more commonly referred to as the Harvard Mark I. |
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| The Mark I was constructed out of switches, relays, rotating shafts, and clutches, and was described as sounding like a "roomful of ladies knitting." The machine contained more than 750,000 components, was 50 feet long, 8 feet tall, and weighed approximately 5 tons! | ||
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IBM automatic
sequence controlled |
Although the Mark I is considered to be the first digital computer, its architecture was significantly different from modern machines. The device consisted of many calculators which worked on parts of the same problem under the guidance of a single control unit. Instructions were read in on paper tape, data was provided on punched cards, and the device could only perform operations in the sequence in which they were received. | |
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| This machine was based on numbers that were 23 digits wide -- it could add or subtract two of these numbers in three-tenths of a second, multiply them in four seconds, and divide them in ten seconds. | ||
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| Aiken was tremendously enthused by computers, but like so many others he didn't anticipate the dramatic changes that were to come. For example, in 1947 he predicted that only six electronic digital computers would be required to satisfy the computing needs of the entire United States. | Although this may cause a wry chuckle today, it is instructive because it accurately reflects the general perception of computers in that era. In those days computers were typically only considered in the context of scientific calculations and data processing for governments, large industries, research establishments, and educational institutions. It was also widely believed that computers would only ever be programmed and used by experts and intellectual heroes (if only they could see us now). (Don't forget to check out Konrad Zuse and his Z3 computer.) | |
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| These notes are abstracted from the book Bebop BYTES Back (An Unconventional Guide to Computers) Copyright Information |
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