The history of general-purpose CPUs is a continuation of the earlier history of computing hardware.

1950s–1960s: Discrete transistor CPUsEdit

The design complexity of CPUs increased as various technologies facilitated building smaller and more reliable electronic devices. The first such improvement came with the advent of the transistor.

ETL Mark III, which began development in 1954[1] and was completed in 1956, was the first stored-program transistor computer. It was created by Japan's Electrotechnical Laboratory.[2][3][4]

In the 1960s, the development of electronic calculators and electronic clocks in Japan helped make integrated circuits economical and practical. In the late 1960s, the first calculator and clock chips began to show that very small computers might be possible with large-scale integration (LSI). This culminated in the invention of the microprocessor, a single-chip CPU.

Late 1960s–early 1970s: LSI and microprocessors Edit

The Intel 4004, released in 1971, was the first commercial microprocessor.[5][6] The origins of the 4004 date back to the the "Busicom Project",[7] which began at Japanese calculator company Busicom in April 1968, when engineer Masatoshi Shima was tasked with designing a special-purpose LSI chipset, along with his supervisor Tadashi Tanba, for use in the Busicom 141-PF desktop calculator with integrated printer.[8][9] His initial design consisted of seven LSI chips, including a three-chip CPU.[7] His design included arithmetic units (adders), multiplier units, registers, read-only memory, and a macro-instruction set to control a decimal computer system.[8] Busicom then wanted a general-purpose LSI chipset, for not only desktop calculators, but also other equipment such as a teller machine, cash register and billing machine. Shima thus began work on a general-purpose LSI chipset in late 1968.[9] Sharp engineer Tadashi Sasaki, who also became involved with its development, conceived of a single-chip microprocessor in 1968, when he discussed the concept at a brainstorming meeting that was held in Japan. Sasaki attributes the basic invention to break the calculator chipset into four parts with ROM (4001), RAM (4002), shift registers (4003) and CPU (4004) to an unnamed woman, a software engineering researcher from Nara Women's College, who was present at the meeting. Sasaki then had his first meeting with Robert Noyce from Intel in 1968, and presented the woman's four-division chipset concept to Intel and Busicom.[10]

Busicom approached the American company Intel for manufacturing help in 1969. Intel, which was more of a memory company back then, had facilities to manufacture the high density silicon gate MOS chip Busicom required.[9] Shima went to Intel in June 1969 to present his design proposal. Due to Intel lacking logic engineers to understand the logic schematics or circuit engineers to convert them, Intel asked Shima to simplify the logic.[9] Intel wanted a single-chip CPU design,[9] influenced by Sharp's Tadashi Sasaki who presented the concept to Busicom and Intel in 1968.[10] The single-chip microprocessor design was then formulated by Intel's Marcian "Ted" Hoff in 1969,[7] simplifying Shima's initial design down to four chips, including a single-chip CPU.[7] Due to Hoff's formulation lacking key details, Shima came up with his own ideas to find solutions for its implementation. Shima was responsible for adding a 10-bit static shift register to make it useful as a printer's buffer and keyboard interface, many improvements in the instruction set, making the RAM organization suitable for a calculator, the memory address information transfer, the key program in an area of performance and program capacity, the functional specification, decimal computer idea, software, desktop calculator logic, real-time I/O control, and data exchange instruction between the accumulator and general purpose register. Hoff and Shima eventually realized the 4-bit microprocessor concept together, with the help of Intel's Stanley Mazor to interpret the ideas of Shima and Hoff.[9] The specifications of the four chips were developed over a period of a few months in 1969, between an Intel team led by Hoff and a Busicom team led by Shima.[7]

In late 1969, Shima returned to Japan.[9] After that, Intel had done no further work on the project until early 1970.[9][7] Shima returned to Intel in early 1970, and found that no further work had been done on the 4004 since he left, and that Hoff had moved on to other projects.[9] Only a week before Shima had returned to Intel,[9] Federico Faggin had joined Intel and become the project leader.[7] After Shima explained the project to Faggin, they worked together to design the 4004.[9] Thus, the chief designers of the chip were Faggin who created the design methodology and the silicon-based chip design, Hoff who formulated the architecture before moving on to other projects, and Shima who produced the initial Busicom design and then assisted in the development of the final Intel design.[8] The 4004 was first introduced in Japan, as the microprocessor for the Busicom 141-PF calculator, in March 1971.[9][8] In North America, the first public mention of the 4004 was an advertisement in the November 15, 1971 edition of Electronic News.[11]

NEC released the μPD707 and μPD708, a two-chip 4-bit CPU, in 1971.[12] They were followed by NEC's first single-chip microprocessor, the μPD700, in April 1972.[13][14] It was a prototype for the μCOM-4 (μPD751), released in April 1973,[13] combining the μPD707 and μPD708 into a single microprocessor.[12] In 1973, Toshiba released the TLCS-12, the first 12-bit microprocessor.[13][15]

1970s: Microprocessor revolution Edit

Intel C4004

Intel 4004 microprocessor.

The first commercial microprocessor, the binary coded decimal (BCD) based Intel 4004, was released by Busicom and Intel in 1971.[8][10] In March 1972, Intel introduced a microprocessor with an 8-bit architecture, the 8008. 4004 designers Federico and Masatoshi Shima went on to design its successor, the Intel 8080, released in 1974. The 8080 was the basis for the Intel 8086, which is a direct ancestor to today's ubiquitous x86 family (including Pentium and Core i7). Every instruction of the 8080 has a direct equivalent in the large x86 instruction set, although the opcode values are different in the latter.

By the mid-1970s, the use of integrated circuits in computers was common. The decade was marked by market upheavals caused by the shrinking price of transistors.

It became possible to put an entire CPU on one printed circuit board. The result was that microcomputers, usually with 16-bit words, and 4K to 64K of memory, became common.

The first single-chip 16-bit microprocessor was introduced in 1975. Panafacom, a conglomerate formed by Japanese companies Fujitsu, Fuji Electric, and Matsushita, introduced the MN1610, a commercial 16-bit microprocessor.[16][17][18] According to Fujitsu, it was "the world's first 16-bit microcomputer on a single chip".[17]

1990s Edit

In the early 1990s, engineers at Japan's Hitachi found ways to compress the reduced instruction sets so they fit in even smaller memory systems than CISCs. Such compression schemes were used for the instruction set of their SuperH series of microprocessors, introduced in 1992.[19] The SuperH instruction set was later adapted for ARM architecture's Thumb instruction set.[20] In applications that do not need to run older binary software, compressed RISCs are growing to dominate sales.

Timeline of events Edit

  • 1968. Busicom's Masatoshi Shima begins designing three-chip CPU that would later evolve into the single-chip Intel 4004 microprocessor.[8]
  • 1968. Sharp engineer Tadashi Sasaki conceives single-chip microprocessor, which he discusses with Busicom and Intel.[10]
  • 1969. Intel 4004's initial design led by Intel's Ted Hoff and Busicom's Masatoshi Shima.[7]
  • 1970. Intel 4004's design completed by Intel's Federico Faggin and Busicom's Masatoshi Shima.[7]
  • 1971. Busicom and Intel release the 4-bit Intel 4004, the first commercial microprocessor.[8]
  • 1971. NEC release the μPD707 and μPD708, a two-chip 4-bit CPU.[12]
  • 1972. NEC release single-chip 4-bit microprocessor, μPD700.[13][14]
  • 1973. NEC release 4-bit μCOM-4 (μPD751),[13] combining the μPD707 and μPD708 into a single microprocessor.[12]
  • 1973. Toshiba release TLCS-12, the first 12-bit microprocessor.[13][15]
  • 1974. Intel release the Intel 8080, an 8-bit microprocessor, designed by Federico Faggin and Masatoshi Shima.
  • 1975. MOS Technology release the 8-bit MOS Technology 6502, the first integrated processor to have an affordable price of $25 when the 6800 rival was $175.
  • 1975. Panafacom introduce the MN1610, the first commercial 16-bit single-chip microprocessor.[21][17][22]
  • 1976. Zilog introduce the 8-bit Zilog Z80, designed by Federico Faggin and Masatoshi Shima.
  • 1978. Intel introduces the Intel 8086 and Intel 8088, the first x86 chips.
  • 1978. Fujitsu releases the MB8843 microprocessor.
  • 1979. Zilog release the Zilog Z8000, a 16-bit microprocessor, designed by Federico Faggin and Masatoshi Shima.
  • 1979. Motorola introduce the Motorola 68000, a 16/32-bit microprocessor.
  • 1981. Stanford MIPS introduced, one of the first reduced instruction set computing (RISC) designs.
  • 1982. Intel introduces the Intel 80286, which was the first Intel processor that could run all the software written for its predecessors, the 8086 and 8088.
  • 1984. Motorola introduces the Motorola 68020+68851, which enabled 32-bit instruction set and virtualization.
  • 1985. Intel introduces the Intel 80386] which adds a 32-bit instruction set to the x86 microarchitecture.
  • 1985. ARM architecture introduced.
  • 1989. Intel introduces the Intel 80486.
  • 1992. Hitachi introduces SuperH architecture,[19] which provides the basis for ARM's Thumb instruction set.[20]
  • 1993. Intel launches the original Pentium microprocessor, the first processor with a x86 superscalar microarchitecture.
  • 1994. ARM's Thumb instruction set introduced,[23] based on Hitachi's SuperH instruction set.[20]
  • 1995. Intel introduces the Pentium Pro which becomes the foundation for the Pentium II, Pentium III, Pentium M and Intel Core architectures.
  • 2000. AMD announced x86-64 extension to the x86 microarchitecture.
  • 2000. AMD hits 1 GHz with its Athlon microprocessor.
  • 2002. Intel released a Pentium 4 with hyper-threading, the first modern desktop processor to implement simultaneous multithreading (SMT).
  • 2003. AMD released the Athlon 64, the first 64-bit consumer CPU.
  • 2003. Intel introduced the Pentium M, a low power mobile derivative of the Pentium Pro architecture.
  • 2005. AMD announced the Athlon 64 X2, their first x86 dual-core processor.
  • 2006. Intel introduces the Core line of CPUs based on a modified Pentium M design.
  • 2008. About ten billion CPUs were produced.
  • 2010. Intel introduced Core i3, i5 and i7 processors.
  • 2011. AMD announced the first consumer 8-core CPU for desktop PCs.
  • 2017. AMD announced Ryzen processors based on Zen architecture.

See alsoEdit


  1. Martin Fransman (1993), The Market and Beyond: Cooperation and Competition in Information Technology, page 19, Cambridge University Press
  2. Early Computers, Information Processing Society of Japan
  3. 【Electrotechnical Laboratory】 ETL Mark III Transistor-Based Computer, Information Processing Society of Japan
  4. Early Computers: Brief History, Information Processing Society of Japan
  5. Mack, Pamela E. (30 November 2005). The Microcomputer Revolution. Retrieved on 2009-12-23.
  6. (PDF) History in the Computing Curriculum. Retrieved 2009-12-23. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 Federico Faggin, The Making of the First Microprocessor, IEEE Solid-State Circuits Magazine, Winter 2009, IEEE Xplore
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Nigel Tout. The Busicom 141-PF calculator and the Intel 4004 microprocessor. Retrieved on November 15, 2009.
  9. 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 Masatoshi Shima, IEEE
  10. 10.0 10.1 10.2 10.3 Aspray, William (1994-05-25). Oral-History: Tadashi Sasaki. Interview #211 for the Center for the History of Electrical Engineering. The Institute of Electrical and Electronics Engineers, Inc.. Retrieved on 2013-01-02.
  11. Gilder, George (1990). Microcosm: the quantum revolution in economics and technology. Simon and Schuster. p. 107. ISBN 978-0-671-70592-3. "Intel's first advertisement for the 4004 appeared in the November 15, 1971 issue of Electronic News" 
  12. 12.0 12.1 12.2 12.3 NEC 751 (uCOM-4). The Antique Chip Collector's Page. Archived from the original on 2011-05-25. Retrieved on 2010-06-11.
  13. 13.0 13.1 13.2 13.3 13.4 13.5 1970年代 マイコンの開発と発展 ~集積回路, Semiconductor History Museum of Japan
  14. 14.0 14.1 Jeffrey A. Hart & Sangbae Kim (2001), The Defense of Intellectual Property Rights in the Global Information Order, International Studies Association, Chicago
  15. 15.0 15.1 Ogdin, Jerry (January 1975). "Microprocessor scorecard". Euromicro Newsletter 1 (2): 43–77. Error: Bad DOI specified. 
  16. 16-bit Microprocessors. CPU Museum. Retrieved on 5 October 2010.
  17. 17.0 17.1 17.2 History. PFU. Retrieved on 5 October 2010.
  18. PANAFACOM Lkit-16, Information Processing Society of Japan
  19. 19.0 19.1
  20. 20.0 20.1 20.2 Nathan Willis (June 10, 2015). Resurrecting the SuperH architecture. LWN.
  21. 16-bit Microprocessors. CPU Museum. Retrieved on 5 October 2010.
  22. PANAFACOM Lkit-16, Information Processing Society of Japan
  23. ARM7TDMI Technical Reference Manual page ii

External linksEdit

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