Four-Phase Systems, Inc., was a computer company, founded by

Lee Boysel Lee Loren Boysel (December 31, 1938 – April 25, 2021) was an American electrical engineer and entrepreneur. While at Fairchild Semiconductor, he developed four-phase logic and built the first integrated circuit with over 100 logic gates, a ...

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 Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois. It was founded by brothers Paul and Joseph Galvin in 1928 and had been named Motorola since 1947. Many of Motorola's products had been ...

in 1982.

History

The idea behind Four-Phase Systems began when Boysel was designing MOS components at

Fairchild Semiconductor Fairchild Semiconductor International, Inc. was an American semiconductor company based in San Jose, California. It was founded in 1957 as a division of Fairchild Camera and Instrument by the " traitorous eight" who defected from Shockley Semi ...

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 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 Robert Norton Noyce (December 12, 1927 – June 3, 1990), nicknamed "the Mayor of Silicon Valley", was an American physicist and entrepreneur who co-founded Fairchild Semiconductor in 1957 and Intel Corporation in 1968. He was also credited w ...

, co-founder of

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

, was an early board member. Boysel arranged for chips to be fabricated by Cartesian, a wafer-processing company founded by another engineer from Fairchild. By spring of 1970, Four-Phase had an engineering-level system operating. Four-Phase showed its system at the

Fall Joint Computer Conference The Joint Computer Conferences were a series of computer conferences in the United States held under various names between 1951 and 1987. The conferences were the venue for presentations and papers representing "cumulative work in the omputerfield ...

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 a substantial level of success, having revenues of $178 million by 1979. As of 1979, their models included:https://bitsavers.trailing-edge.com/pdf/datapro/datapro_reports_70s-90s/Four_Phase/M11-435-10_7908_Four-Phase_System_IV.pdf IV-90 chassis 2

The IV/30 and IV/55 were intended for only one or two data entry/display stations, while the IV/40 and higher were intended for multiple high-volume data entry stations and independent data processing, and the IV/60 and higher could be made into small computer systems. In 1982, Four-Phase was sold to

for a $253 million stock exchange (equivalent to $ today). The former location of the business on N De Anza Blvd is now Apple's

Infinite Loop In computer programming, an infinite loop (or endless loop) is a sequence of instructions that, as written, will continue endlessly, unless an external intervention occurs, such as turning off power via a switch or pulling a plug. It may be inte ...

campus.

System

The Four-Phase CPU used a

24-bit Notable 24-bit machines include the CDC 924 – a 24-bit version of the CDC 1604, CDC lower 3000 series, SDS 930 and SDS 940, the ICT 1900 series, the Elliott 4100 series, and the Datacraft minicomputers/ Harris H series. The term SWORD ...

word size. It fit on a single card and was composed of three AL1 chips, three

read-only memory Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing sof ...

(ROM) chips, and three

random logic Random logic is a semiconductor circuit design technique that translates high-level logic descriptions directly into hardware features such as AND and OR gates. The name derives from the fact that few easily discernible patterns are evident in the a ...

chips. A memory card used Four-Phase's 1K

random-access memory Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows ...

(RAM) chips. The system also included a built-in video controller which could drive up to 32 terminals from a character

buffer Buffer may refer to: Science * Buffer gas, an inert or nonflammable gas * Buffer solution, a solution used to prevent changes in pH * Lysis buffer, in cell biology * Metal ion buffer * Mineral redox buffer, in geology Technology and engineeri ...

.Brochure, System IV/70, Four Phase Systems
From the Computer History Museum. Accessed online June 11, 2010. Also see

AL1 chip

The AL1 is an 8-bit

bit slice Bit slicing is a technique for constructing a Processor (computing), processor from modules of processors of smaller bit width, for the purpose of increasing the word length; in theory to make an arbitrary ''n''-bit central processing unit ...

which contains eight registers and an

arithmetic logic unit In computing, an arithmetic logic unit (ALU) is a Combinational logic, combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on ...

(ALU). It was implemented using

four-phase logic Four-phase logic is a type of, and design methodology for dynamic logic. It enabled non-specialist engineers to design quite complex ICs, using either PMOS or NMOS processes. It uses a kind of 4-phase clock signal to smooth out power delivery ...

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 the AL1 was not called a

microprocessor A microprocessor is a computer processor (computing), processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, a ...

, or used as one at the time, it was later dubbed one in connection with litigation in the 1990s, when

Texas Instruments Texas Instruments Incorporated (TI) is an American multinational semiconductor company headquartered in Dallas, Texas. It is one of the top 10 semiconductor companies worldwide based on sales volume. The company's focus is on developing analog ...

claimed to have patented the microprocessor. In response, 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, where the ROM and its associated

latch A latch or catch (called sneck in Northern England and Scotland) is a type of mechanical fastener that joins two or more objects or surfaces while allowing for their regular separation. A latch typically engages another piece of hardware on the ...

acted like a

microcode In processor design, microcode serves as an intermediary layer situated between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. It consists of a set of hardware-level instructions ...

controller to provide control lines for memory read/write, selecting an ALU operation, and providing the address of the next microcode instruction. The AL1 and its chipset is arguably the first microprocessor used in a commercial product (vs the

Intel 4004 The Intel 4004 was part of the 4 chip MCS-4 micro computer set, released by the Intel, Intel Corporation in November 1971; the 4004 being part of the first commercially marketed microprocessor chipset, and the first in a long line of List of I ...

, the first commercially available microprocessor).

References

*{{Dead link, date=December 2019 , bot=InternetArchiveBot , fix-attempted=yes
Lee Boysel – Making Your First Million And Other Tips for Aspiring Entrepreneurs

External links

Four-Phase Systems AL1 Processor – 8-bits by Lee Boysel
1969 establishments in California 1981 establishments in California American companies established in 1969 American companies disestablished in 1981 Companies based in Cupertino, California Computer companies established in 1969 Computer companies disestablished in 1981 Computers using bit-slice designs Defunct computer companies based in California Defunct computer companies of the United States Defunct computer hardware companies Technology companies based in the San Francisco Bay Area