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Software as Hardware: Apollo’s Rope Memory

Programs for the Apollo Guidance Computer were encoded by painstakingly threading wires through tiny magnetic cores

2 min read
Photo by Mark Richards/Computer History Museum
Photo: Mark Richards/Computer History Museum

Alan Kay, the pioneering computer scientist, has observed that “hardware is really just software crystallized early.” The rope memory device shown here, a prototype created in 1963 by Burroughs Corp. [PDF], makes Kay’s point. In rope memory, bits of information are represented by threads of wire and tiny doughnut-shaped magnetic cores. A core with wire threaded through the center represents a 1; an empty core represents a 0. In this way, the pattern of wires can form a computer program—software crystallized as hardware, in other words.

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How Ted Hoff Invented the First Microprocessor

Hoff thought designing 12 custom chips for a calculator was crazy, so he created the Intel 4004

14 min read
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How Ted Hoff Invented the First Microprocessor
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The rays of the rising sun have barely reached the foothills of Silicon Valley, but Marcian E. (Ted) Hoff Jr. is already up to his elbows in electronic parts, digging through stacks of dusty circuit boards. This is the monthly flea market at Foothill College, and he rarely misses it.

Ted Hoff is part of electronics industry legend. While a research manager at Intel Corp., then based in Mountain View, he realized that silicon technology had advanced to the point that, with careful engineering, a complete central processor could fit on a chip. Teaming up with Stanley Mazor and Federico Faggin, he created the first commercial microprocessor, the Intel 4004.

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