Four-Phase Systems, Inc. , was a computer company, founded by Lee Boysel and others, which built one of the earliest computers using semiconductor main memory and MOS LSI logic. The company was incorporated in February 1969 and had moderate commercial success. It was acquired by Motorola in 1982.
20-486: AL1 may refer to: Four-Phase Systems AL1 , the first microprocessor (1969), produced by Four-Phase Systems AL1, original designation of British Rail Class 81 A designation for main-belt asteroids AL1, a postcode district in the AL postcode area Al1 , a 2017 EP by Seventeen See also [ edit ] Futurama#Language [REDACTED] Topics referred to by
40-589: A mil (plural mils ). The words are shortened forms of the English and Latin words for "thousand" ( mille in Latin). In international engineering contexts, confusion can arise because mil is a formal unit name in North America but mil or mill is also a common colloquial clipped form of millimetre . The units are considerably different: a millimetre is approximately 39 mils. The thou, or mil,
60-495: A built-in video controller which could drive up to 32 terminals from a character buffer in main memory. The AL1 is an 8-bit bit slice which contains eight registers and an arithmetic logic unit (ALU). It was implemented using four-phase logic and used over a thousand gates, with an area of 130 by 120 mils (3.3 mm by 3 mm). The chip was described in an April 1970 article in Computer Design magazine. Although
80-429: A single mil, and even if such dividing is accomplished, it is unclear to the naked eye, being discernible but not useful for measuring.) During the following half century, such measuring instruments, previously expensive rarities, became widespread, everyday tools among machinists. Bringing more metrology into machining made possible, for example, designing an assembly in the form of an engineering drawing , then having
100-536: A substantial level of success, having revenues of $ 178 million by 1979. In 1982, Four-Phase was sold to Motorola for a $ 253 million stock exchange (equivalent to $ 799 million today). The former location of the business on N De Anza Blvd is now Apple's Infinite Loop campus. The Four-Phase CPU used a 24-bit word size. It fit on a single card and was composed of three AL1 chips, three read-only-memory (ROM) chips, and three random logic chips. A memory card used Four-Phase's 1K RAM chips. The system also included
120-406: A thou" or "one ten thousandth". Other common terms used in machining with Imperial units involve adding tenths together to achieve a specific tolerance or measurement. For example, "five tenths," is typically a measurement or tolerance of five ten-thousandths of an inch, and written as 0.0005 inches. "Three tenths," as another example, is written as 0.0003 inches Machining "to within a few tenths"
140-448: Is about 16 thou. Communication about sizes smaller than a 64th of an inch was subjective and hampered by a degree of ineffability —while phrases such as "scant 64th" or "heavy 64th" were used, they were imprecise. Dimensions and geometry could be controlled to high accuracy, but this was done by comparative methods: comparison against templates or other gauges, feeling the degree of drag of calipers, or simply repeatably cutting, relying on
160-491: Is arguably the first microprocessor used in a commercial product (vs the Intel 4004 , the first commercially available microprocessor). Thousandth of an inch A thousandth of an inch is a derived unit of length in a system of units using inches . Equal to 1 ⁄ 1000 of an inch , a thousandth is commonly called a thou / ˈ θ aʊ / (used for both singular and plural) or, particularly in North America,
180-446: Is different from Wikidata All article disambiguation pages All disambiguation pages Four-Phase Systems AL1 The idea behind Four-Phase Systems began when Boysel was designing MOS components at Fairchild Semiconductor in 1967. Boysel wrote a manifesto explaining how a computer could be built from a small number of MOS chips. Fairchild made Boysel head of a MOS design group, which he used to design parts satisfying
200-410: Is generally attributed to Joseph Whitworth who wrote in 1857: ... instead of our engineers and machinists thinking in eighths, sixteenths and thirty-seconds of an inch, it is desirable that they should think and speak in tenths, hundredths, and thousandths ... Whitworth's main point was to advocate decimalization in place of fractions based on successive halving; but in mentioning thousandths, he
220-440: Is most commonly used in engineering and manufacturing in non-metric countries. For example, in specifying: There are also compound units such as "mils per year" used to express corrosion rates. The word "mil" appears in the following different units: In areas of machining where the thou is used, 0.0001 inches (2.54 micrometres ) is often treated as a basic unit and can be referred to as "one tenth", meaning "one tenth of
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#1732783335084240-410: Is often considered very accurate, and at or near the extreme limit of tolerance capability in most contexts. Greater accuracy (tolerance ranges inside one tenth) apply in only a few contexts: in plug gauge and gauge block manufacturing or calibration, they are typically expressed in millionths of an inch or, alternatively, in micrometres; in nanotechnology , nanometres or picometres are used. In
260-453: The AL1 was not called a microprocessor , or used as one at the time, it was later dubbed one in connection with litigation in the 1990s, when Texas Instruments claimed to have patented the microprocessor. In response, Lee Boysel assembled a system in which a single 8-bit AL1 was used as part of a courtroom demonstration computer system, together with ROM, RAM and an input-output device. The AL1
280-486: The United States, mil was once the more common term, but as use of the metric system has become more common, thou has replaced mil among most technical users to avoid confusion with millimetres . Today both terms are used, but in specific contexts one is traditionally preferred over the other. 1 thou is equal to: The introduction of the thousandth of an inch as a base unit in engineering and machining
300-421: The kinds of process designs that could work, because they limited the degree of separation of concerns that could occur. The introduction of the thou as a base unit for machining work required the dissemination of vernier calipers and screw micrometers throughout the trade, as the unit is too small to be measured with practical repeatability using rules alone. (Most rule markings were far too wide to mark
320-414: The positioning consistency of jigs, fixtures, and machine slides. Such work could only be done in craft fashion: on-site, by feel, rather than at a distance working from drawings and written notes. Although measurement was certainly a part of the daily routine, the highest-precision aspects of the work were achieved by feel or by gauge, not by measuring (as in determining counts of units). This in turn limited
340-626: The requirements of his putative computer. After doing this, Boysel left to start Four-Phase in October 1968, initially with two other engineers from his Fairchild group as well as others. Boysel was not sued by Fairchild, perhaps because of chaos caused by a change in Fairchild management at that time. When the company was incorporated in February 1969, he was joined by other engineers from the Fairchild group. Robert Noyce , co-founder of Intel ,
360-448: The same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=AL1&oldid=1168333634 " Category : Letter–number combination disambiguation pages Hidden categories: Short description
380-472: Was also broaching the idea of a finer division than had been used previously. Until then, workers such as millwrights , boilermakers , and machinists in the Anglosphere measured only in traditional fractions of an inch, divided via successive halving, usually only as far as 64ths (1, 1 ⁄ 2 , 1 ⁄ 4 , 1 ⁄ 8 , 1 ⁄ 16 , 1 ⁄ 32 , 1 ⁄ 64 ). Each 64th
400-497: Was an early board member. Boysel arranged for chips to be fabricated by Cartesian, a wafer-processing company founded by another engineer from Fairchild. Four-Phase showed its system at the Fall Joint Computer Conference in 1970. By June 1971, Four-Phase IV/70 computers were in use at four different customers, and by March 1973, they had shipped 347 systems to 131 customers. The company enjoyed
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