Four-Phase Systems AL1
| General information | |
|---|---|
| Launched | January 1971 |
| Designed by | Four-Phase Systems |
| Common manufacturer |
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| Performance | |
| Max. CPU clock rate | 1 MHz |
| Data width | 8 bits |
| Address width | 8 bits |
| Physical specifications | |
| Transistors |
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| Package |
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| Socket | |
| Architecture and classification | |
| Application | System IV/70 |
| Technology node | 10 μm |
| Support status | |
| Unsupported | |
The AL1 was an early 8-bit microprocessor slice designed by Four-Phase Systems and unveiled in February 1970. The chip was first used as part of Four-Phase's System IV/70 24-bit minicomputer to be used with terminals shipped in January 1971. It has been widely reported as one of the first microprocessor central processing units (CPU) publicly disseminated, pre-dating the Intel 4004 by one year. In modern terms, the AL1 is a bit-slice design. The company never advertised the AL1 as an independent product and did not sell it to other customers; the 4004 was the first such design to be sold in standalone form. The AL1 was later updated as the AL4.
The AL1 served as a key example of prior art in a series of patent lawsuits initiated by Texas Instruments and Gilbert Hyatt regarding the basic technology of the microprocessor. Lee Boysel demonstrated the function of the AL1 in court to demonstrate that the design incorporated all of the patented concepts on a chip completed prior to either party's claim.