science · 24 January 1948 · 76 years ago
In 1948, IBM dedicated its "SSEC" in New York City. The Selective Sequence Electronic Calculator handled both data and instructions using electronic circuits made with 13,500 vacuum tubes and 21,000 relays. It occupied three sides of a 30-ft x 60-ft room. On the back wall, three punches and thirty readers provided paper-tape storage. Banks of vacuum tube circuits for card reading and sequence control and 36 paper tape readers comprising the table-lookup section occupied the left wall. Most of the right wall was filled by the electronic arithmetic unit and storage. In the center of the room were card readers, card punches, printers, and the operator's console. It was visible to pedestrians on the sidewalk outside.
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