Intel 4004

Last updated
Intel 4004
Intel C4004.jpg
White ceramic Intel C4004 microprocessor with grey traces
ProducedFrom late 1971 to 1981
Common manufacturer(s)
  • Intel
Max. CPU clock rate 740 kHz
Min. feature size 10 µm
Instruction set 4-bit BCD oriented
Transistors2,250 [1]
Data width4 bits
Address width12 (multiplexed)
Successor Intel 4040
ApplicationBusicom calculator, arithmetic manipulation

The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. It was the first commercially available microprocessor, [2] 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. [3]

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.

Central processing unit Central component of any computer system which executes input/output, arithmetical, and logical operations

A central processing unit (CPU), also called a central processor or main processor, is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logic, controlling, and input/output (I/O) operations specified by the instructions. The computer industry has used the term "central processing unit" at least since the early 1960s. Traditionally, the term "CPU" refers to a processor, more specifically to its processing unit and control unit (CU), distinguishing these core elements of a computer from external components such as main memory and I/O circuitry.

Intel American semiconductor chip manufacturer

Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, in the Silicon Valley. It is the world's second largest and second highest valued semiconductor chip manufacturer based on revenue after being overtaken by Samsung Electronics, and is the inventor of the x86 series of microprocessors, the processors found in most personal computers (PCs). Intel ranked No. 46 in the 2018 Fortune 500 list of the largest United States corporations by total revenue. Intel is incorporated in Delaware.


The 4004 was the first random logic circuit integrated in one chip using the MOS (metal–oxide–semiconductor) silicon gate technology (SGT). It was the most advanced integrated circuit (IC) design undertaken up until then. Hoff, head of the Application Research department, had formulated an architectural proposal consisting of a block architecture with an instruction set during 1969, while interacting with Busicom engineers led by Shima and with the assistance of Stan Mazor. Hoff and Mazor were not MOS chip designers and did not participate in the actual design or development of the 4004. The chip design was realized independently in the MOS department, different from Application Research. It could only be realized by a designer with deep knowledge of MOS process technology and of the new SGT. Faggin was hired at Intel in April 1970 from Fairchild Semiconductor as the project leader and designer of the 4004 and he transferred to manufacturing a fully functional chip in March 1971. Faggin brought to Intel his mastery of the SGT that he had invented at Fairchild (in 1968) and used it to develop his novel methodology for random chip design that was key to making the first and all the early Intel microprocessors. Shima, representing Busicom, was engaged with Hoff and Mazor in the architectural phase during 1969 and he also assisted Faggin with the final logic design for 6 months in 1970.

MOSFET Transistor used for amplifying or switching electronic signals.

The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET), also known as the metal–oxide–silicon transistor (MOS transistor, or MOS), is a type of field-effect transistor that is fabricated by the controlled oxidation of a semiconductor, typically silicon. It has an insulated gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. The MOSFET is the basic building block of modern electronics. Since its invention by Mohamed Atalla and Dawon Kahng at Bell Labs in November 1959, the MOSFET has become the most widely manufactured device in history, with an estimated total of 13 sextillion (1.3 × 1022) MOS transistors manufactured between 1960 and 2018.

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 ICs 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.

Fairchild Semiconductor American company

Fairchild Semiconductor International, Inc. was an American semiconductor company based in San Jose, California. Founded in 1957 as a division of Fairchild Camera and Instrument, it became a pioneer in the manufacturing of transistors and of integrated circuits. Schlumberger bought the firm in 1979 and sold it to National Semiconductor in 1987; Fairchild was spun off as an independent company again in 1997. In September 2016, Fairchild was acquired by ON Semiconductor.

In November 1971, with the prophetic ad "Announcing a new era in integrated electronics", the 4004 was made commercially available to the general market. The 4004 was the first commercially available monolithic processor, fully integrated in one small chip. [4] Such a feat of integration was made possible by the use of the then-new silicon gate technology for integrated circuits, originally developed by Faggin (with Tom Klein) at Fairchild Semiconductor in 1968, which allowed twice the number of random-logic transistors and an increase in speed by a factor of five compared to the incumbent MOS aluminum gate technology. [5] Faggin also invented the bootstrap load with silicon gate and the “buried contact”, improving speed and circuit density compared with aluminum gate. [6] [7] [8] [9] [10]

Transistor Basic electronics component

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.

The 4004 microprocessor, the 4001 ROM, 4002 RAM, and 4003 Shift Register constituted the four chips in the Intel MCS-4 chip-set. With these components, small computers with varying amounts of memory and I/O facilities could be built.

Contemporaneous CPU chips

Three other CPU chip designs were produced at about the same time: the Four-Phase Systems AL1, done in 1969; the MP944, completed in 1970 and used in the F-14 Tomcat fighter jet; and the Texas Instruments TMS-0100 chip, announced on September 17, 1971. The MP944 uses several chips for the implementation of the CPU function. The TMS0100 chip was presented as a “calculator on a chip” with the original designation TMS1802NC. [11] This chip contains a very primitive CPU and can only be used to implement various simple four-function calculators. It is the precursor of the TMS1000, introduced in 1974, which is considered the first microcontroller--i.e., a computer on a chip containing not only the CPU, but also ROM, RAM, and I/O functions. [12] The MCS-4 family of four chips developed by Intel, of which the 4004 is the CPU or microprocessor, was far more versatile and powerful than the single-chip TMS1000, allowing the creation of a variety of small computers for various applications.

Four-Phase Systems 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 1981.

Texas Instruments American semiconductor designer and manufacturer

Texas Instruments Incorporated (TI) is an American technology company that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globally. Its headquarters are in Dallas, Texas, United States. TI is one of the top-10 semiconductor companies worldwide, based on sales volume. Texas Instruments's focus is on developing analog chips and embedded processors, which account for more than 80% of their revenue. TI also produces TI digital light processing technology and education technology products including calculators, microcontrollers and multi-core processors. To date, TI has more than 45,000 patents worldwide.

Zilog, the first company entirely dedicated to microprocessors and microcontrollers, was started by F. Faggin and Ralph Ungermann at the end of 1974. These devices formed the basis for later models of microcontrollers.

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.

History and production

National Semiconductor was a second source manufacturer of the 4004, under their part number INS4004. KL National INS4004.jpg
National Semiconductor was a second source manufacturer of the 4004, under their part number INS4004.

The first public mention of 4004 was an advertisement in the November 15, 1971, edition of Electronic News . [14] The first delivery was to Busicom for their engineering prototype calculator in March 1971, [15] [10] followed by their 141-PF prototype calculator commercially available in the market in July 1971. [16] Packaged in a 16-pin ceramic dual in-line package, the 4004 was the first commercially available computer processor designed and manufactured by chip maker Intel, which had previously made semiconductor memory chips. The chief designers of the chip were Federico Faggin, the leader of the project after the architectural definition was finalized with Busicom, who created the design methodology and the silicon-based chip design; Ted Hoff who formulated the architecture, [17] [18] both of Intel, and Masatoshi Shima of Busicom who assisted in the development.

Electronic News was a publication that covered the electronics industry, from semiconductor equipment and materials to military/aerospace electronics to supercomputers. It was originally a weekly trade newspaper, which covered all aspects of the electronics industry, including semiconductors, computers, software, communications, space and even television electronics.

Dual in-line package Type of electronic component package

In microelectronics, a dual in-line package, or dual in-line pin package (DIPP) is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (PCB) or inserted in a socket. The dual-inline format was invented by Don Forbes, Rex Rice and Bryant Rogers at Fairchild R&D in 1964, when the restricted number of leads available on circular transistor-style packages became a limitation in the use of integrated circuits. Increasingly complex circuits required more signal and power supply leads ; eventually microprocessors and similar complex devices required more leads than could be put on a DIP package, leading to development of higher-density chip carriers. Furthermore, square and rectangular packages made it easier to route printed-circuit traces beneath the packages.

A semiconductor material has an electrical conductivity value falling between that of a conductor, such as metallic copper, and an insulator, such as glass. Its resistance decreases as its temperature increases, which is the behaviour opposite to that of a metal. Its conducting properties may be altered in useful ways by the deliberate, controlled introduction of impurities ("doping") into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers which include electrons, ions and electron holes at these junctions is the basis of diodes, transistors and all modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits and others. Silicon is a critical element for fabricating most electronic circuits.

Faggin, the sole chip designer among the engineers on the MCS-4 project, was the only one with experience in metal-oxide semiconductor (MOS) random logic and circuit design. He also had the crucial knowledge of the new silicon gate process technology with self-aligned gates, which he had created at Fairchild in 1968. At Fairchild in 1968, Faggin also designed and manufactured the world's first commercial IC using SGT, the Fairchild 3708 [19] that was featured on the cover of Electronics (Sept. 29, 1969). [20] As soon as he joined the Intel MOS Department he created a new random logic design methodology based on silicon gate, [16] and contributed many technology and circuit design inventions that enabled their single chip microprocessor to become a reality. His methodology set the design style for all the early Intel microprocessors and later for the Zilog Z80. He also led the MCS-4 project and was responsible for its successful outcome (1970–1971). Marcian "Ted" Hoff, head of the Application Research Department, contributed the architectural proposal for Busicom working with Stanley Mazor in 1969, then he moved on to other projects. When asked where he got the ideas for the architecture of the first microprocessor, Hoff related that Plessey, "a British tractor company", [21] had donated a minicomputer to Stanford, and he had "played with it some" while he was there. Shima designed the Busicom calculator firmware and assisted Faggin during the first six months of the implementation. The manager of Intel's MOS Design Department was Leslie L. Vadász. [22] At the time of the MCS-4 development, Vadasz's attention was completely focused on the mainstream business of semiconductor memories and he left the leadership and the management of the MCS-4 project to Faggin.

Busicom had designed their own special-purpose LSI chipset for use in their Busicom 141-PF calculator with integrated printer. They based their design on the architecture of the Olivetti Programma 101, the world's first tabletop programmable calculator, which Olivetti introduced in 1965. Busicom commissioned Intel to develop their design for production. Like the Olivetti Programma 101, the Busicom design used serial read-write memory. The Busicom memory was based on MOS shift registers rather than the costly Olivetti memory based on magnetostriction wire.

Intel determined the Busicom design was too complex, since serial memories required more components, and would use 40 pins, a packaging standard different from Intel's own 16-pin standard. Intel proposed to develop a new design which could be produced with standard 16-pin DIP packaging, and would have a reduced instruction set. [23] The memory simplification would come from using Intel's newly developed dynamic RAM memory. This new design was the 4004 chip, which is one of a set of four chips, along with ROM, DRAM, and serial-to-parallel shift register chips. The 4004 was subsequently designed by Federico Faggin [24] using silicon gate technology and built of approximately 2,300 transistors [1] and was followed the next year by the first ever 8-bit microprocessor, the 3,500 transistor 8008 (and the 4040, a revised and improved 4004). It was not until the development of the 40-pin 8080 in 1974, a project conceived and directed by Faggin [25] that the address and data buses would be separated, giving faster and simpler access to memory.

The 4004 employs a 10 µm process silicon-gate enhancement load pMOS technology on a 12 mm² die [26] and can execute approximately 92,000 instructions per second; a single instruction cycle is 10.8 microseconds. [27] The original clock rate design goal was 1 MHz, the same as the IBM 1620 Model I.[ citation needed ]

The Intel 4004 was designed by physically cutting sheets of Rubylith into thin strips to lay out the circuits to be printed, a process made obsolete by current computer graphic design capabilities. [28]

For the purpose of testing the produced chips, Faggin developed a tester for silicon wafers of MCS-4 family that was itself driven by 4004 chip. The tester also served as a proof for the management that Intel 4004 microprocessor could be used not only in calculator-like products, but also for control applications. [29]

Name and variants

The Unicom 141P is an OEM version of the Busicom 141-PF Unicom 141P Calculator 3.jpg
The Unicom 141P is an OEM version of the Busicom 141-PF

When Faggin designed the MCS-4 family, he also christened the chips with distinct names: 4001, 4002, 4003, and 4004, breaking away from the numbering scheme used by Intel at that time which would have required the names 1302, 1105, 1507, and 1202 respectively. Had he followed Intel's number sequence, the idea that the chips were part of a family of components intended to work seamlessly together would have been lost. [30] Intel's early numbering scheme for integrated circuits used a four-digit number for each component. The first digit indicated the process technology used, the second digit indicated the generic function, and the last two digits of the number were used to indicate the sequential number in the development of the component. The 8008 microprocessor was originally called 1201, per Intel's naming conventions. Before its market introduction, the 1201 was renamed 8008, following the new naming convention started with the 4001/2/3/4.

Tadashi Sasaki attributes the basic invention to break the calculator into four parts with ROM (4001), RAM (4002), shift registers (4003) and CPU (4004) to an unnamed woman from the Nara Women's College present at a brainstorming meeting that was held in Japan prior to his first meeting with Robert Noyce from Intel, leading up to the Busicom deal. [31]

The 4004 is part of the MCS-4 family of LSI chips that can be used to build digital computers with varying amounts of memory. The other members of the MCS-4 family are memories and input/output circuits, which are necessary to implement a complete computer. The 4001 is a ROM (read-only memory) with four lines of output; the 4002 is a RAM (random access memory) with four lines of input/output. The 4003 is a static shift register to be used for expanding the I/O lines; e.g., for keyboard scanning or controlling a printer.[ citation needed ]

The 4004 includes functions for direct low-level control of memory chip selection and I/O, which are not normally handled by the microprocessor; however, its functionality is limited in that it cannot execute code from RAM and is limited to whatever instructions are provided in ROM (or an independently loaded RAM working as ROM—in either case, the processor is itself unable to write or transfer data into an executable memory space). The RAM and ROM parts were also unusual in their integration of output (and, in the ROMs, input) ports that significantly reduced the minimum part count in an MCS-4 system, but required inclusion of a certain amount of processor-like logic on the chips themselves to accept, decode and execute relatively high-level data transfer instructions.

The standard arrangement for a 4004 system is anything up to 16 × 4001 ROM chips (in a single bank) and 16 × 4002 RAM chips (in four banks of four), which together provide the 4KB program storage, 1024 + 256 nibbles of data/status storage, plus 64 output and 64 input/output external data/control lines (which can themselves be used to operate, e.g. a 4003). Intel's MCS-4 documentation, however, claims that up to 48 ROM and RAM chips (providing up to 192 external control lines) "in any combination" can be connected to the 4004 "with simple gating hardware", but declines to give any further detail or examples of how this would actually be achieved.

Technical specifications

Two C4004 DIPs with one opened to show the die. C4004 (Intel).jpg
Two C4004 DIPs with one opened to show the die.
Intel 4004 architectural block diagram 4004 arch.svg
Intel 4004 architectural block diagram
Intel 4004 DIP chip pinout 4004 dil.svg
Intel 4004 DIP chip pinout
Intel 4004 registers
111009080706050403020100(bit position)
Condition codes
 C Carry flag
Index registers
Program counter
PCProgram Counter
Push-down address call stack
PC1Call level 1
PC2Call level 2
PC3Call level 3

Logic levels


Support chips

The minimum system specification described by Intel consists of a 4004 with a single 256-byte 4001 program ROM; there is no explicit need for separate RAM in minimal complexity applications thanks to the 4004's large number of onboard index registers, which represent the equivalent of 16 x 4-bit or 8 x 8-bit characters (or a mixture) of working RAM, nor for simple interface chips thanks to the ROM's built-in I/O lines. However, as project complexity increases, the various other support chips start to become useful.


Numerous versions of the Intel MCS-4 line of processors were produced. The earliest versions, marked C (like C4004), were ceramic and used a zebra pattern of white and gray on the back of the chips, often called "grey traces". The next generation of the chips was plain white ceramic (also marked C), and then dark grey ceramic (D). Many of the more recent versions of MCS-4 family were also produced with plastic (P).

The ceramic C4004 variant without grey traces. Intel C4004 b.jpg
The ceramic C4004 variant without grey traces.
The ceramic D4004 variant. Intel D4004.jpg
The ceramic D4004 variant.
The plastic P4004 variant. Intel P4004.jpg
The plastic P4004 variant.


The first commercial product to use a microprocessor was the Busicom calculator 141-PF. The 4004 was also used in the first microprocessor-controlled pinball game, a prototype produced by Dave Nutting Associates for Bally in 1974.

According to Nick Tredennick, a microprocessor designer and expert witness to the Boone/Hyatt patent case"[ clarification needed ]

Here are my opinions from [the] study [I conducted for the patent case]. The first microprocessor in a commercial product was the Four Phase Systems AL1. The first commercially available (sold as a component) microprocessor was the 4004 from Intel. [34]

A popular myth has it that Pioneer 10, the first spacecraft to leave the solar system, used an Intel 4004 microprocessor. According to Dr. Larry Lasher of Ames Research Center, the Pioneer team did evaluate the 4004, but decided it was too new at the time to include in any of the Pioneer projects.[ citation needed ] The myth was repeated by Federico Faggin himself in a lecture for the Computer History Museum in 2006. [35]

Legacy and value

In the lower-right corner of the CPU are the initials "F.F." Legendary Chip Designer Betting on Human Mind.jpg
In the lower-right corner of the CPU are the initials "F.F."

Federico Faggin signed the 4004 with his initials because he knew that his silicon gate design embodied "the essence of the microprocessor". A corner of the die reads "F.F." [30]

On November 15, 2006, the 35th anniversary of the 4004, Intel celebrated by releasing the chip's schematics, mask works, and user manual. [36] A fully functional 41 × 58 cm, [37] 130× scale replica of the Intel 4004 was built using discrete transistors and put on display in 2006 at the Intel Museum in Santa Clara, California. [38]

On October 15, 2010, Faggin, Hoff, and Mazor were awarded the National Medal of Technology and Innovation by President Barack Obama for their pioneering work on the 4004. [39]


  1. although the early documentation states "0.75MHz", this is at odds with the timing diagrams which specify a minimum overall cycle time of 1350ns (=741kHz) and a maximum of 2010ns (=498kHz)
  2. This statistic comes from the same document as the "0.75MHz" claim and which appears to inaccurately round off the true figures for the purposes of summary. 850 µs with a minimum 10.8µs cycle time would in truth be 78.7 machine cycles, or roughly 629 clock ticks. As the processor is locked into an 8-tick cycle, it's more likely this operation would take 79 or even 80 full cycles, thus 632 to 640 ticks and 853 to 864 µs (or 854 to 865 µs at a true 740kHz), and reducing the actual execution speed to 1157 ~ 1172 (or 1156 ~ 1171) 8-digit additions per second
  3. However, this could only be used as working / data memory, and was non-executable: program code could not be stored in or run from RAM, as the processor kept the two memory areas strictly segregated at the microcode level. Instruction fetching forced assertion of the ROM chip-select line (and deassertion of the RAM select lines), and the chip had no way to "write" data to anything other than an IO port whilst the ROM area was selected.
  4. The only part of the 4004 memory space capable of storing executable code, though also usable for general purpose storage

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.

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.

MOS Technology 6502 8-bit microprocessor

The MOS Technology 6502 is an 8-bit microprocessor that was designed by a small team led by Chuck Peddle for MOS Technology. When it was introduced in 1975, the 6502 was, by a considerable margin, the least expensive microprocessor on the market. It initially sold for less than one-sixth the cost of competing designs from larger companies, such as Motorola and Intel, and caused rapid decreases in pricing across the entire processor market. Along with the Zilog Z80, it sparked a series of projects that resulted in the home computer revolution of the early 1980s.

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 Z80 8-bit microprocessor

The Z80 is an 8-bit microprocessor introduced by Zilog as the startup company's first product. The Z80 was conceived by Federico Faggin in late 1974 and developed by him and his 11 employees starting in early 1975. The first working samples were delivered in March 1976, and it was officially introduced on the market in July 1976. With the revenue from the Z80, the company built its own chip factories and grew to over a thousand employees over the following two years.

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.

Marcian Hoff American electrical engineer

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

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.

Busicom company

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.

Depletion-load NMOS logic form of nMOS logic family

In integrated circuits, depletion-load NMOS is a form of digital logic family that uses only a single power supply voltage, unlike earlier nMOS logic families that needed more than one different power supply voltage. Although manufacturing these integrated circuits required additional processing steps, improved switching speed and the elimination of the extra power supply made this logic family the preferred choice for many microprocessors and other logic elements.

Electronics industry global industry

The electronics industry, especially meaning consumer electronics, emerged in the 20th century and has now become a global industry worth billions of dollars. Contemporary society uses all manner of electronic devices built in automated or semi-automated factories operated by the industry. Products are assembled from integrated circuits, principally by photolithography of printed circuit boards.

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.

Each time Intel launched a new microprocessor, they simultaneously provided a System Development Kit (SDK) allowing engineers, university students, and others to familiarise themselves with the new processor's concepts and features. The SDK single-board computers allowed the user to enter object code from a keyboard or upload it through a communication port, and then test run the code. The SDK boards provided a system monitor ROM to operate the keyboard and other interfaces. Kits varied in their specific features but generally offered optional memory and interface configurations, a serial terminal link, audio cassette storage, EPROM program memory. Intel's Intellec development system could download code to the SDK boards.

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.


  1. 1 2 "Intel 4004 Fun Facts". Retrieved 2011-07-06.
  2. "The Story of the Intel® 4004". Intel.
  3. Faggin, F. (1992). "The Birth of the Microprocessor". Byte, pp. 145–150, March 1992.
  4. Cass, Stephen. "Chip Hall of Fame: Intel 4004 Microprocessor" . Retrieved February 5, 2019.
  5. F. Faggin, T. Klein: "Silicon-Gate Technology". "Solid State Electronics", 1970, Vol. 13, pp. 1125–1144
  6. Faggin, Federico. "The New Methodology for Random Logic Design" . Retrieved June 3, 2017.
  7. Faggin, Federico. "The Bootstrap Load" . Retrieved June 3, 2017.
  8. Faggin, Federico. "The Buried Contact" . Retrieved June 3, 2017.
  9. ""Inductee Detail"". National Inventors Hall of Fame. 2016-07-25.
  10. 1 2 Faggin, Federico. "The MOS Silicon Gate Technology and the First Microprocessors" (PDF). Rivista del Nuovo Cimento. 38 (12). Retrieved 2017-06-05.
  11. Woerner, Joerg (November 16, 2001). "The "Calculator-on-a-chip"". Datamath Calculator Museum. Retrieved 22 March 2016.
  12. Woerner, Joerg (February 26, 2001). "Texas Instruments: They invented the Microcontroller". Datamath Calculator Museum. Retrieved 22 March 2016.
  13. Intel 4004 microprocessor family, retrieved 2011 Dec 14
  14. 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
  15. Busicom Calculator Engineering Prototype (Gift of Federico Faggin to the Computer History Museum, Mountain View, California)
  16. 1 2 Faggin, Federico; Hoff, Marcian; Mazor, Stanley; Shima, Masatoshi (1996-12-01). "The history of the 4004". IEEE Micro. 16 (6): 10–20. doi:10.1109/40.546561.
  17. "Inductee Detail - National Inventors Hall of Fame".
  18. Faggin, Federico. "Ted Hoff's Role in the Microprocessor" . Retrieved June 3, 2017.
  19. Faggin, Federico. "A faster generation of MOS devices with low thresholds is riding the crest of the new wave, silicon-gate IC's" . Retrieved June 3, 2017.
  20. Faggin, Federico. "Earliest Published Papers" . Retrieved June 3, 2017.
  21. Possibly he had confused the Plessey name with that of Massey Ferguson, makers of agricultural machinery.
  22. "The Intel4004". Retrieved 2008-03-15.
  23. Nigel Tout. "The Busicom 141-PF calculator and the Intel 4004 microprocessor" . Retrieved November 15, 2009.
  24. “Silicon Valley” by Moira Johnston, page 466, National Geographic, October 1982.
  25. Faggin, Federico. "Exempt performance and salary review'" . Retrieved June 3, 2017.
  26. "History of Computing Industrial Era 1970 - 1971". 2010-10-19. Retrieved 2016-05-05. In February Intel releases the 4004 microprocessor to the market. It has 12 sq mm die size and 16 pins which fit into a motherboard.
  27. "Intel 4004 datasheet" (PDF) (published 2010-07-06). 1987. Retrieved 2011-07-06.
  28. "Intel's Accidental Revolution". Archived from the original on 2012-07-11. Retrieved 2009-07-30.
  29. Hendrie, Gardner (2006). "Oral History of Federico Faggin" (PDF). Computer History Museum. Retrieved 2017-01-24.
  30. 1 2 "Federico Faggin's Signature". Retrieved 2012-08-21.
  31. 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.
  32. Intel's museum archive i4004 datasheet
  33. IMPORTANT section at page 25:
  34. "Dissertation 2004" (PDF). Retrieved 2017-11-14.
  35. "Intel 4004 Microprocessor 35th Anniversary". YouTube. Retrieved 2011-07-06.
  36. Intel 4004 Microprocessor Historical Materials, Intel Museum, 2009-11-15, accessed 2009-11-18
  37. "4004 @ 44: SVG Mask Artwork; New Busicom 141-PF replica PCB; Printer emulator". 2015-11-20. Retrieved 2016-05-05.
  38. "Intel 4004 -- 45th Anniversary Project". 2015-11-15. Retrieved 2016-04-02. including fully functional 130x scale replicas of the 4004 built using discrete transistors, museum-durable keyboards and slide switches, and video display electronics.
  39. "President Obama Honors Nation's Top Scientists and Innovators" (Press release). October 15, 2010.


Historical documents

Further reading