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On the left, the NEC TK-80 kit, based on Intel 8080 chip, on the centre, Busicom calculator motherboard, based on Intel 4004 chip, and on the right, the Busicom calculator, fully assembled in Ueno, Tokyo Busicom.JPG
On the left, the NEC TK-80 kit, based on Intel 8080 chip, on the centre, Busicom calculator motherboard, based on Intel 4004 chip, and on the right, the Busicom calculator, fully assembled in Ueno, Tokyo

Busicom was a Japanese company that owned the rights to Intel's first microprocessor, the Intel 4004, which they created in partnership with Intel in 1970.

Japan Island country in East Asia

Japan is an island country in East Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asian continent and stretches from the Sea of Okhotsk in the north to the East China Sea and the Philippine Sea in the south.

Microprocessor Computer processor contained on an integrated-circuit chip

A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory and provides results as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.

Intel 4004 4-bit central processing unit

The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. It was the first commercially available microprocessor, and the first in a long line of Intel CPUs. The chip design, implemented with the MOS silicon gate technology, started in April 1970, and was created by Federico Faggin who led the project from beginning to completion in 1971. Marcian Hoff formulated and led the architectural proposal in 1969, and Masatoshi Shima contributed to the architecture and later to the logic design. The first commercial sale of the fully operational 4004 occurred in March 1971 to Busicom Corp. of Japan for its 141-PF electronic calculator, for which it was originally designed and built as a custom chip.


Busicom asked Intel to design a set of integrated circuits for a new line of programmable electronic calculators in 1969. [1] [2] In doing this, they spurred the invention of Intel's first microprocessor to be commercialized, [3] the Intel 4004. Busicom owned the exclusive rights to the design and its components in 1970 but shared them with Intel in 1971. [4]

Integrated circuit electronic circuit manufactured by lithography; set of electronic circuits on one small flat piece (or "chip") of semiconductor material, normally silicon

An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material that is normally silicon. The integration of large numbers of tiny MOS transistors into a small chip results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to circuit design has ensured the rapid adoption of standardized IC's in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.

Calculator electronic device used to perform operations of arithmetic

An electronic calculator is typically a portable electronic device used to perform calculations, ranging from basic arithmetic to complex mathematics.

Two companies have done business as "Busicom" over the years; the Nippon Calculating Machine Corp, Ltd and subsequently Broughtons & Co.(Bristol) Ltd of the UK.

Nippon Calculating Machine Corporation, Ltd

The Unicom 141P and the NCR 18-36 were OEM versions of the Busicom 141-PF Unicom 141P Calculator 3.jpg
The Unicom 141P and the NCR 18-36 were OEM versions of the Busicom 141-PF


The Nippon Calculating Machine Corp was incorporated in 1945 and changed its name in 1967 to Business Computer Corporation, Busicom. Due to a recession in Japan in 1974, Busicom became the first major Japanese company in the calculator industry to fail. Originally, they made Odhner type mechanical calculators and then moved on to electronic calculators always using state of the art designs. They made the first calculator with a microprocessor for their top of the line machines [5] and they were the first to make calculators with an all-in-one calculator chip, the Mostek MK6010, for their line of inexpensive machines.

Odhner Arithmometer

The Odhner Arithmometer was a very successful pinwheel calculator invented in Russia in 1873 by W. T. Odhner, a Swedish immigrant. Its industrial production officially started in 1890 in Odhner's Saint Petersburg workshop. Even though the machine was very popular, the production only lasted thirty years until the factory was nationalised and closed down during the Russian revolution of 1917.

One of their last mechanical calculators is the HL-21, an Odhner type machine. [6] Their first calculator with a microprocessor is the Busicom 141-PF. Their entry based calculators, the Busicom LE-120A (Handy-LE) and LE-120S (Handy), [7] were the first to fit in a pocket and also the first calculators to use an LED display.


In order to limit production cost, Busicom wanted to design a calculator engine that would be based on a few integrated circuits (ICs), containing some ROMs and shift registers and that could be adapted to a broad range of calculators by just changing the ROM IC chips. Busicom's engineers came up with a design that required 12 ICs [8] and asked Intel, a company founded one year earlier in 1968 for the purpose of making solid state random-access memory (RAM), to finalize and manufacture their calculator engine. People who were influential in convincing Busicom to switch to using microprocessors were Tadashi Sasaki and Robert Noyce. [9]

Read-only memory non-volatile memory used in computers and other electronic devices; class of storage medium used in computers and other electronic devices

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 software that is rarely changed during the life of the system, sometimes known as firmware. Software applications for programmable devices can be distributed as plug-in cartridges containing read-only memory.

In digital circuits, a shift register is a cascade of flip flops, sharing the same clock, in which the output of each flip-flop is connected to the "data" input of the next flip-flop in the chain, resulting in a circuit that shifts by one position the "bit array" stored in it, "shifting in" the data present at its input and 'shifting out' the last bit in the array, at each transition of the clock input.

Random-access memory Form of computer data storage

Random-access memory is a form of computer memory that can be read and changed in any order, typically used to store working data and machine code. A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older magnetic tapes and drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement.

Intel's Ted Hoff was assigned to studying Busicom's design, and came up with a much more elegant, 4 ICs architecture centered on what was to become the 4004 microprocessor surrounded by a mixture of 3 different ICs containing ROM, shift registers, input/output ports and RAM—Intel's first product (1969) was the 3101 Schottky TTL bipolar 64-bit SRAM. [10] Busicom's management agreed to Hoff's new approach [11] and the chips' implementation was led by Federico Faggin who had previously developed the Silicon Gate Technology at Fairchild Semiconductor. It was this technology that made possible the design of the microprocessor and the dynamic RAMs. The 4 ICs were delivered to Busicom in January 1971. [12]

Marcian Hoff American electrical engineer

Marcian Edward "Ted" Hoff Jr. is one of the inventors of the microprocessor.

Schottky barrier potential energy barrier in metal-semiconductor junctions

A Schottky barrier, named after Walter H. Schottky, is a potential energy barrier for electrons formed at a metal–semiconductor junction. Schottky barriers have rectifying characteristics, suitable for use as a diode. One of the primary characteristics of a Schottky barrier is the Schottky barrier height, denoted by ΦB. The value of ΦB depends on the combination of metal and semiconductor.

Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function and the amplifying function ; it is the same naming convention used in resistor–transistor logic (RTL) and diode–transistor logic (DTL).

In mid-1971 Busicom, which had exclusive right to the design and its components, asked Intel to lower their prices. [4] Intel renegotiated their contract and Busicom gave up its exclusive rights to the chips. [4] A few months later, on November 15, 1971, Intel announced the immediate availability of the first microprocessor chipset family, the MCS-4 micro computer set (all from the Busicom design) with an advertisement in Electronic News.

Broughtons of Bristol

Broughtons of Bristol is a company selling and maintaining a broad line of business machines. [13] They used to buy most of their equipment from Busicom and bought the Busicom trade name when Busicom went bankrupt in 1974.

Related Research Articles

Intel 8080 8-bit microprocessor

The Intel 8080 ("eighty-eighty") was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock rate or frequency limit was 2 MHz, and with common instructions using 4, 5, 7, 10, or 11 cycles this meant that it operated at a typical speed of a few hundred thousand instructions per second. A faster variant 8080A-1 became available later with clock frequency limit up to 3.125 MHz.

Motorola 6800 8-bit microprocessor

The 6800 is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips. A significant design feature was that the M6800 family of ICs required only a single five-volt power supply at a time when most other microprocessors required three voltages. The M6800 Microcomputer System was announced in March 1974 and was in full production by the end of that year.

Zilog American manufacturer

Zilog, Inc. is an American manufacturer of 8-bit and 16-bit microcontrollers. Its most famous product is the Z80 series of 8-bit microprocessors that were compatible with the Intel 8080 but significantly cheaper. The Z80 was widely used during the 1980s in many popular home computers such as the TRS-80 and the ZX Spectrum, as well as arcade games such as Pac-Man. The company also made 16- and 32-bit processors, but these did not see widespread use. From the 1990s, the company focused primarily on the microcontroller market.

Intel 8008 byte-oriented microprocessor

The Intel 8008 is an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It is an 8-bit CPU with an external 14-bit address bus that could address 16 KB of memory. Originally known as the 1201, the chip was commissioned by Computer Terminal Corporation (CTC) to implement an instruction set of their design for their Datapoint 2200 programmable terminal. As the chip was delayed and did not meet CTC's performance goals, the 2200 ended up using CTC's own TTL-based CPU instead. An agreement permitted Intel to market the chip to other customers after Seiko expressed an interest in using it for a calculator.

Intel 4040

The Intel 4040 microprocessor was the successor to the Intel 4004. It was introduced in 1974. The 4040 employed a 10 μm silicon gate enhancement load PMOS technology, was made up of 3,000 transistors and could execute approximately 62,000 instructions per second. General performance, bus layout and instruction set was identical to the 4004, with the main improvements being in the addition of extra lines and instructions to recognise and service interrupts and hardware Halt/Stop commands, an extended internal stack and general-purpose "Index" register space to handle nesting of several subroutines and/or interrupts, plus a doubling of program ROM address range.

The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as the transistor and later the integrated circuit. By 1959 discrete transistors were considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Computer main memory slowly moved away from magnetic core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size and power consumption of computers.

Federico Faggin Italian physicist and electrical engineer

Federico Faggin is an Italian-American physicist, engineer, inventor and entrepreneur. He is best known for designing the first commercial microprocessor, the Intel 4004. He led the 4004 (MCS-4) project and the design group during the first five years of Intel's microprocessor effort. Faggin also created, while working at Fairchild Semiconductor in 1968, the self-aligned MOS (metal-oxide-semiconductor) silicon-gate technology (SGT), which made possible MOS semiconductor memory chips, CCD image sensors, and the microprocessor. After the 4004, he led development of the Intel 8008 and 8080, using his SGT methodology for random logic chip design, which was essential to the creation of early Intel microprocessors. He was co-founder and CEO of Zilog, the first company solely dedicated to microprocessors, and led the development of the Zilog Z80 and Z8 processors. He was later the co-founder and CEO of Cygnet Technologies, and then Synaptics.

The history of computing is longer than the history of computing hardware and modern computing technology and includes the history of methods intended for pen and paper or for chalk and slate, with or without the aid of tables.

Masatoshi Shima Japanese computer pioneer

Masatoshi Shima is a Japanese electronics engineer. He was one of the designers of the world's first microprocessor, the Intel 4004, producing the initial three-chip CPU design at Busicom in 1968, before working with Intel's Ted Hoff, Stanley Mazor and Federico Faggin on the final single-chip CPU design from 1969 to 1970.

In computer architecture, 4-bit integers, memory addresses, or other data units are those that are 4 bits wide. Also, 4-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size. A group of four bits is also called a nibble and has 24 = 16 possible values.

Mostek company

Mostek was an integrated circuit manufacturer, founded in 1969 by L. J. Sevin, Louay E. Sharif, Richard L. Petritz and other ex-employees of Texas Instruments. Initially their products were manufactured in Worcester, Massachusetts, however by 1974 most of its manufacturing was done in the Carrollton, Texas facility on Crosby Road. At its peak in the late 1970s, Mostek held an 85% market share of the dynamic random-access memory (DRAM) memory chip market worldwide, until being eclipsed by Japanese DRAM manufacturers who offered equivalent chips at lower prices by dumping memory on the market.

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

Stanley Mazor is an American microelectronics engineer who was born on 22 October 1941 in Chicago, Illinois. He is one of the co-inventors of the world's first microprocessor, the Intel 4004, together with Ted Hoff, Masatoshi Shima, and Federico Faggin.

The history of electronic engineering is a long one. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".

Tadashi Sasaki was a Japanese engineer who was influential in founding Busicom, driving the development of the Intel 4004 microprocessor, and later driving Sharp into the LCD calculator market.

This is the history of science and technology in Japan.


  1. Augarten S.: Bit by Bit, page 261, Ticknor & Fields, 1984
  2. Stine, G.H., The Untold Story of the Computer Revolution, page 163, Arbor House, 1985
  3. Augarten S.: Bit by Bit, page 262-263, Ticknor & Fields, 1984
  4. 1 2 3 Reid, T.R.: The Chip, page 141-142, Simon and Schuster, 1984
  5. Busicom 141-FP
  6. Calculateur Busicom HL-21
  7. Pocket-size calculator Busicom LE-120A "HANDY-LE"
  8. Augarten S.: Bit by Bit, page 263-265, Ticknor & Fields, 1984
  9. 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 2013-01-02.
  10. 1969 - Schottky-Barrier Diode Doubles the Speed of TTL Memory & Logic Computer History Museum. Retrieved September 23, 2011.
  11. Agreement between Intel & NCM
  12. Faggin, Federico; Hoff, Marcian E.; Mazor, Stanley; Shima, Masatoshi (December 1996), "The History of the 4004", IEEE Micro, Los Alamitos: IEEE Computer Society, 16 (6): 10–19, doi:10.1109/40.546561, ISSN   0272-1732
  13. "Busicom Business Machines". Broughton & Co. (Bristol) Ltd.