Chip Hall of Fame: Motorola MC68000 Microprocessor

The processor that powered the original Macintosh, as well as the beloved Amiga computers

1 min read
Motorola MC68000 Microprocessor
Photo: Pauli Rautakorpi

Motorola MC68000 MicroprocessorImage:  Pauli Rautakorpi

MC68000 Micro-processor

Manufacturer: Motorola

Category: Processors

Year: 1979

Motorola was late to the 16-bit microprocessor party, so it decided to arrive in style. The hybrid 16-bit/32-bit MC68000 packed in 68,000 transistors, more than double the number of Intel’s 8086. Internally it was a 32-⁠bit processor, but a 32-bit address and/or data bus would have made it prohibitively expensive, so the 68000 used 24-bit address and 16-bit data lines. The 68000 seems to have been the last major processor designed using pencil and paper. “I circulated reduced-size copies of flowcharts, execution-unit resources, decoders, and control logic to other project members,” says Nick Tredennick, who designed the 68000’s logic. The copies were small and difficult to read, and his bleary-eyed colleagues eventually found a way to make that clear. “One day I came into my office to find a credit-card-size copy of the flowcharts sitting on my desk,” Tredennick recalls. The 68000 found its way into all the early Macintosh computers, as well as the Amiga and the Atari ST. Big sales numbers came from embedded applications in laser printers, arcade games, and industrial controllers. But the 68000 was also the subject of one of history’s greatest near misses, right up there with Pete Best losing his spot as a drummer for the Beatles. IBM wanted to use the 68000 in its PC line, but the company went with Intel’s 8088 because, among other things, the 68000 was still relatively scarce. As one observer later reflected, had Motorola prevailed, the Windows-Intel duopoly known as Wintel might have been Winola instead.

Photo:

Underneath that gold cover is a 32-bit processor, but it’s connected to the outside world with a package that only had pins for 16-bit data.

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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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