Ask most engineers who built the first microprocessor and they will say Intel, 1971, the 4004. The real story has more people in it.
The 4004 was a 4-bit chip designed by Federico Faggin, an Italian physicist who had earlier replaced aluminium gates with silicon self-aligned gates to make the first silicon-gate MOS chip at Fairchild Semiconductor in 1968. At Intel he used the same technique, working with Marcian Hoff, Stanley Mazor and Masatoshi Shima. The 4004 is generally credited as the first commercially available microprocessor, though historians still argue over who deserves the title of inventor.
A calculator maker’s gamble
The chip began as a job for Busicom, a Japanese calculator company. Busicom had proposed a multi-chip design in 1969, and Faggin’s team turned it into a single-chip one. Then Busicom ran into financial trouble and gave up its exclusive rights. In November 1971 Intel started selling the 4004 and its support chips as a stand-alone product for general computing.
Customers were scarce. Within months more powerful chips overshadowed it, and its few uses included a couple of pinball machines, a word processor and a system for counting votes. The 8-bit Intel 8008 arrived in 1972.
The rivals nobody remembers
Other engineers were chasing the same goal. Garrett AiResearch built a chipset for the Navy’s new F-14 Tomcat fighter. Its designers included Ray Holt and Steve Geller, and the design was complete by 1970. Because the F-14 computer was classified, the MP944 chipset stayed unknown to the public until 1998.
Lee Boysel, who left Fairchild in 1968 to cofound Four-Phase Systems, designed the AL1 in 1969. It was an 8-bit slice with eight registers and an arithmetic logic unit. In the 1990s, during litigation brought by Texas Instruments, Boysel built a courtroom demonstration computer around a single AL1 with a 1969 datestamp.
Texas Instruments had its own entry. After Intel took on a processor project for Computer Terminal Corp. in San Antonio, the bigger company asked CTC whether it could build one too. TI began a single-chip CPU around April 1970, first called the TMX 1795. CTC tested it and said no. Intel’s chip was not ready until the end of 1971 either, and CTC kept building its Datapoint 2200 processor from a board of bipolar chips.
Even the word is older than the chip. Viatron Computer Systems used “microprocessor” in an October 1968 announcement, but its version was a set of 18 custom MOS chips on three boards that ran a smart terminal.
The 4004 did not win on timing alone. It could run instructions held in external ROM, so it could serve in a general-purpose computer, while rival calculator chips from Mostek, General Instrument and Texas Instruments could only do arithmetic.
Sources
- Microprocessor – Wikipedia
- Microprocessor – Wikipedia
- The Surprising Story of the First Microprocessors
