Micral is a series of
microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (P ...
s produced by the French company Réalisation d'Études Électroniques (
R2E), beginning with the Micral N
in early 1973. The Micral N was one of the first commercially available microprocessor-based computers.
In 1986, three judges at
The Computer Museum, Boston
The Computer Museum was a Boston, Massachusetts, museum that opened in 1979 and operated in three locations until 1999. It was once referred to as TCM and is sometimes called the Boston Computer Museum. When the museum closed and its space became ...
–
Apple II
Apple II ("apple Roman numerals, two", stylized as Apple ][) is a series of microcomputers manufactured by Apple Computer, Inc. from 1977 to 1993. The Apple II (original), original Apple II model, which gave the series its name, was designed ...
designer and Apple Inc. co-founder Steve Wozniak, early Micro Instrumentation and Telemetry Systems, MITS employee and ''PC World'' publisher David Bunnell, and the museum's associate director and curator Oliver Strimpel – awarded the title of "first
personal computer
A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...
using 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 ...
" to the 1973 Micral. The Micral N was the earliest commercial, non-kit personal computer based on a microprocessor (in this case, the
Intel 8008
The Intel 8008 ("''eight-thousand-eight''" or "''eighty-oh-eight''") is an early 8-bit microprocessor capable of addressing 16 KB of memory, introduced in April 1972. The 8008 architecture was designed by Computer Terminal Corporation (CTC) and ...
).
The
Computer History Museum
The Computer History Museum (CHM) is a computer museum in Mountain View, California. The museum presents stories and artifacts of Silicon Valley and the Information Age, and explores the Digital Revolution, computing revolution and its impact ...
currently says that the Micral is one of the earliest commercial, non-kit personal computers.
The 1971
Kenbak-1
The Kenbak-1 is considered by the Computer History Museum, the Mimms Museum of Technology and Art and the American Computer Museum to be the world's first "personal computer", invented by John Blankenbaker (born 1929) of Kenbak Corporation in ...
, invented before the first microprocessor, is considered to be the world's first "personal computer". That machine did not have a one-chip
CPU
A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...
but instead was based purely on
small-scale integration
An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components ...
TTL chips.
Micral N
R2E founder
André Truong Trong Thi (
EFREI degree, Paris), a French immigrant from
Vietnam
Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...
, asked Frenchman
François Gernelle
François Gernelle (born December 20, 1944) is a French engineer, computer scientist and entrepreneur famous for inventing the first micro-computer using a micro-processor, the Micral N.
Education
In the late 1960s, Gernelle earned an engine ...
to develop the Micral N computer for the
Institut National de la Recherche Agronomique
The Institut national de la recherche agronomique (; ; abbr. INRA ) was a French public research institute dedicated to agricultural science. It was founded in 1946 and is a Public Scientific and Technical Research Establishment under the join ...
(INRA), starting in June 1972. Alain Perrier of INRA was looking for a computer for process control in his crop
evapotranspiration
Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the Atmosphere of Earth, atmosphere. It covers both water evaporation (movement of w ...
measurements. The software was developed by Benchetrit. Beckmann designed the I/O boards and controllers for peripheral magnetic storage. Lacombe was responsible for the memory system, I/O high speed channel, power supply and front panel. Gernelle invented the Micral N, which was much smaller than existing
minicomputer
A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s, built significantly smaller and sold at a much lower price than mainframe computers . By 21st century-standards however, a mini is ...
s. The January 1974 Users Manual called it "the first of a new generation of mini-computer whose principal feature is its very low cost," and said, "MICRAL's principal use is in
process control
Industrial process control (IPC) or simply process control is a system used in modern manufacturing which uses the principles of control theory and physical industrial control systems to monitor, control and optimize continuous Industrial processe ...
. It does not aim to be an universal mini-computer."
[Micral N Users Manual](_blank)
p. 66, 76. January 1974. bitsavers.org.

The computer was to be delivered in December 1972, and Gernelle, Lacombe, Benchetrit and Beckmann had to work in a cellar in
Châtenay-Malabry for 18 hours a day in order to deliver the computer in time. The software, the
ROM
Rom, or ROM may refer to:
Biomechanics and medicine
* Risk of mortality, a medical classification to estimate the likelihood of death for a patient
* Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac
* ...
-based MIC 01
monitor
Monitor or monitor may refer to:
Places
* Monitor, Alberta
* Monitor, Indiana, town in the United States
* Monitor, Kentucky
* Monitor, Oregon, unincorporated community in the United States
* Monitor, Washington
* Monitor, Logan County, Wes ...
and the ASMIC 01
assembler,
was written on an Intertechnique
Multi-8 minicomputer using a
cross assembler. The computer was based on an Intel 8008 microprocessor clocked at 500 kHz. It had a
backplane
A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect s ...
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a motor vehicle that carries significantly more passengers than an average car or van, but fewer than the average rail transport. It is most commonly used ...
, called the ''Pluribus'' with 74-pin connector. 14 boards could be plugged in a Pluribus. With two Pluribus, the Micral N could support up to 24 boards. The computer used
MOS memory
Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembe ...
instead of
core memory
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (laboratory), a highly specialized shared research resource
* Core (manufacturing), used in casting and molding
* Core (optical fiber), ...
. The Micral N could support parallel and serial
input/output
In computing, input/output (I/O, i/o, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, such as another computer system, peripherals, or a human operator. Inputs a ...
. It had 8 levels of
interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...
and a
stack
Stack may refer to:
Places
* Stack Island, an island game reserve in Bass Strait, south-eastern Australia, in Tasmania’s Hunter Island Group
* Blue Stack Mountains, in Co. Donegal, Ireland
People
* Stack (surname) (including a list of people ...
. The computer was programmed with
punched tape
file:PaperTapes-5and8Hole.jpg, Five- and eight-hole wide punched paper tape
file:Harwell-dekatron-witch-10.jpg, Paper tape reader on the Harwell computer with a small piece of five-hole tape connected in a circle – creating a physical program ...
, and used a
teleprinter
A teleprinter (teletypewriter, teletype or TTY) is an electromechanical device that can be used to send and receive typed messages through various communications channels, in both point-to-point (telecommunications), point-to-point and point- ...
or
modem
The Democratic Movement (, ; MoDem ) is a centre to centre-right political party in France, whose main ideological trends are liberalism and Christian democracy, and that is characterised by a strong pro-Europeanist stance. MoDem was establis ...
for I/O. The
front panel
A front panel was used on early electronic computers to display and allow the alteration of the state of the machine's internal CPU register, registers and computer memory, memory. The front panel usually consisted of arrays of electric light, ...
console
Console may refer to:
Computing and video games
* System console, a physical device to operate a computer
** Virtual console, a user interface for multiple computer consoles on one device
** Command-line interface, a method of interacting with ...
was optional, offering customers the option of designing their own console to match a particular application.
It was delivered to the INRA in January 1973, and commercialized in February 1973 for FF 8,500 (about $1,750) making it a cost-effective replacement for minicomputers which augured the era of the PC.
France had produced the first microcomputer. A year would pass before the first North American microcomputer,
SCELBI
SCELBI was an early model of microcomputer based on the Intel 8008 processor. The company SCELBI (derived from SCientific-ELectronics-BIology) Computer Consulting in 1973, by Nat Wadsworth. The SCELBI 8H was marketed in 1974 and was delivered eith ...
, was advertised in the March 1974 issue of ''
QST'', an amateur radio magazine.
Indeed, INRA was originally planning to use
PDP-8
The PDP-8 is a family of 12-bit minicomputers that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units sold during the model's lifetime. Its basic design follows the pi ...
computers for process control, but the Micral N could do the same for a fifth of the cost. An 8-inch
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...
reader was added to the Micral in December 1973, following a command of the
Commissariat à l'Energie Atomique
The French Alternative Energies and Atomic Energy Commission, or CEA ( French: Commissariat à l'énergie atomique et aux énergies alternatives), is a French public government-funded research organisation in the areas of energy, defense and sec ...
. This was made possible by the pile-canal, a buffer that could accept one megabyte per second. In 1974, a keyboard and screen were fitted to the Micral computers. A hard disk (first made by
CAELUS
Caelus or Coelus (; ) was a primordial List of Roman deities, god of the sky in Roman mythology and Religion in ancient Rome, theology, Roman art, iconography, and Latin literature, literature (compare 'sky', 'heaven', whence English ''celestia ...
then by
Diablo) became available in 1975. In 1979, the Micral 8031 D was equipped with a 5" 1/4 inches hard disk of 5 Megabytes made by
Shugart.
Later models

Following the April 1974 introduction of the
Intel 8080
The Intel 8080 is Intel's second 8-bit computing, 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a week ...
, R2E introduced the second and third Micral models, 8008-based at 1 MHz Micral G
and 8080-based at 1 MHz Micral S
.
In November 1975, R2E signed
Warner & Swasey Company
The Warner & Swasey Company was an American manufacturer of machine tools, Measuring instrument, instruments, and special machinery. It operated as an independent business firm, based in Cleveland, from its founding in 1880 until its acquisiti ...
as the exclusive manufacturer and marketer of the Micral line in the United States and Canada. Warner & Swasey marketed its Micral-based system for industrial data processing applications such as engineering data analysis, accounting and inventory control. R2E and Warner & Swasey displayed the Micral M
multiple microcomputer system at the June 1976 National Computer Conference. The Micral M consists of up to eight Micral S microcomputers, each with its own local memory and sharing the common memory so the local and common memory look like one monolithic memory for each processor. The system has a distributed multiprocessor operating system R2E said was based on sharing common resources and real-time task management.
Some time after the July 1976 introduction of the
Zilog Z80
The Zilog Z80 is an 8-bit computing, 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be Backward compatibility, software-compatible with the ...
, came the Z80-based Micral CZ. The 8080-based Micral C
, an intelligent
CRT
CRT or Crt most commonly refers to:
* Cathode-ray tube, a display
* Critical race theory, an academic framework of analysis
CRT may also refer to:
Law
* Charitable remainder trust, United States
* Civil Resolution Tribunal, Canada
* Columbia ...
terminal designed for word processing and automatic typesetting, was introduced in July 1977. It has two
Shugart SA400 minifloppy drives and a panel of system control and
sense switches below the minifloppy drives.
Business application language (BAL) and
FORTRAN are supported. By October, R2E had set up an American subsidiary, R2E of America, in Minneapolis. The Micral V Portable
(1978) could run FORTRAN and assembler under the Sysmic operating system, or BAL. The original Sysmic operating system was renamed
Prologue
A prologue or prolog (from Ancient Greek πρόλογος ''prólogos'', from πρό ''pró'', "before" and λόγος ''lógos'', "speech") is an opening to a story that establishes the context and gives background details, often some earlier st ...
in 1978. Prologue was able to perform
real-time
Real-time, realtime, or real time may refer to:
Computing
* Real-time computing, hardware and software systems subject to a specified time constraint
* Real-time clock, a computer clock that keeps track of the current time
* Real-time Control Syst ...
multitasking, and was a
multi-user
Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leavi ...
system. R2E offered
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/Intel 8085, 85-based microcomputers by Gary Kildall of Digital Research, Dig ...
for the Micral C in 1979.

The R2E Micral CCMC
Portal portable microcomputer made its official appearance in September 1980 at the SICOB show in Paris. It was designed and marketed by the studies and developments department of François Gernelle of the French firm R2E Micral at the request of the company CCMC specializing in payroll and accounting. The
Portal was based on an Intel 8085 processor, 8-bit, clocked at 2 MHz. It weighed and its dimensions were 45 cm x 45 cm x 15 cm, It provided total mobility. Its operating system was Prologue.
Later Micrals used the
Intel 8088
The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers ...
. The last Micral designed by François Gernelle was the 9020. In 1981, R2E was bought by
Groupe Bull
Bull SAS (also known as Groupe Bull, Bull Information Systems, or simply Bull) is a French computer company headquartered in Les Clayes-sous-Bois, in the western suburbs of Paris. The company has also been known at various times as Bull General ...
. Starting with the Bull Micral 30
, which could use both Prologue and
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...
, Groupe Bull transformed the Micral computers into a line of PC compatibles. François Gernelle left Bull in 1983.
Legacy
Truong's R2E sold about 90,000 units of the Micral that were mostly used in
vertical applications such as highway toll booths and process control.
Litigation followed after Truong started claiming that he alone invented the first personal computer. The courts did not judge in favor of Truong, who was declared "the businessman, but not the inventor", giving in 1998 the sole claim as inventor of the first personal computer to Gernelle and the R2E engineering team.
In the mid-1970s,
Philippe Kahn
Philippe Kahn (born March 16, 1952) is a French engineer, entrepreneur, and founder of four technology companies: Borland, Starfish Software, LightSurf Technologies, and Fullpower Technologies. Kahn is credited with creating the first camera ...
was a programmer for the Micral. Kahn later headed
Borland
Borland Software Corporation was a computing technology company founded in 1983 by Niels Jensen, Ole Henriksen, Mogens Glad, and Philippe Kahn. Its main business was developing and selling software development and software deployment products. B ...
which released
Turbo Pascal
Turbo Pascal is a software development system that includes a compiler and an integrated development environment (IDE) for the programming language Pascal (programming language), Pascal running on the operating systems CP/M, CP/M-86, and MS-DOS. ...
and
Sidekick
A sidekick is a close companion or colleague who is, or is generally regarded as, subordinate to those whom they accompany.
Origins
The first recorded use of the term dates from 1896. It is believed to have originated in pickpocket slang of ...
in 1983.
Paul G. Allen, the co-founder of Microsoft with
Bill Gates
William Henry Gates III (born October 28, 1955) is an American businessman and philanthropist. A pioneer of the microcomputer revolution of the 1970s and 1980s, he co-founded the software company Microsoft in 1975 with his childhood friend ...
, bought a Micral N by the auctioneer Rouillac at the Artigny Castle in France, on June 11, 2017, for his Seattle museum
Living Computers: Museum + Labs.
"Association MO5.com", a French preservation group, announced in 2023 that they had acquired a Micral N two years before in 2021. They are restoring it and documenting it.
Micral computer models
R2E series
* 1973 : Micral N, first microcomputer, built by François Gernelle.
* 1974 : Micral G,
Intel 8008
The Intel 8008 ("''eight-thousand-eight''" or "''eighty-oh-eight''") is an early 8-bit microprocessor capable of addressing 16 KB of memory, introduced in April 1972. The 8008 architecture was designed by Computer Terminal Corporation (CTC) and ...
at 1 MHz, 16K RAM
[http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/08/279/8279852.pdf ]
* 1974 : Micral S,
Intel 8080
The Intel 8080 is Intel's second 8-bit computing, 8-bit microprocessor. Introduced in April 1974, the 8080 was an enhanced successor to the earlier Intel 8008 microprocessor, although without binary compatibility.'' Electronic News'' was a week ...
[http://bitsavers.org/pdf/r2e/MICRAL_S_Microcomputer_Handbook_Aug74.pdf ]
* 1976 : Micral M, ''distributed system'', Intel 8080 × 8
[http://www.vintagecomputer.net/fjkraan/comp/divcomp/doc/R2E_Micral.pdf ]
* 1977 : Micral C, Intel 8080, 24K RAM, integrated monitor, floppy disc drive
[http://bitsavers.org/pdf/r2e/MICRAL_C_Operators_Manual_Oct77.pdf ]
* 1978 : Micral V, Intel 8080, 32K RAM, portable
[http://bitsavers.org/pdf/r2e/MICRAL_V_Portable_Microcomputer_System_Dec78.pdf ]
Bull series

* 1979 : Micral 80–30,
Zilog Z80
The Zilog Z80 is an 8-bit computing, 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be Backward compatibility, software-compatible with the ...
* 1980 : Micral 80–20,
Zilog Z80A at 3 MHz
* 1980 :
Portal,
Intel 8085
The Intel 8085 ("''eighty-eighty-five''") is an 8-bit microprocessor produced by Intel and introduced in March 1976. It is software-binary-code compatibility, binary compatible with the more-famous Intel 8080. It is the last 8-bit microprocesso ...
at 2 MHz
* 1981 : Micral P2, Zilog Z80 at 5 MHz, 64K RAM
* 1981 : Micral X, Zilog Z80, 10MB hard disc (CII Honeywell Bull D140)
* 1983 : Micral 90–20,
Intel 8088
The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor is a variant of the Intel 8086. Introduced on June 1, 1979, the 8088 has an eight-bit external data bus instead of the 16-bit bus of the 8086. The 16-bit registers ...
at 5 MHz
* 1983 : Micral 90–50,
Intel 8086
The 8086 (also called iAPX 86) is a 16-bit computing, 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-b ...
at 8 MHz, 256K RAM
PC compatible series
* 1985 : Bull Micral 30, Intel 8088 at 4.77 MHz,
PC-XT compatible (
''Nanoréseau''''
'' network machine)
* 1986 : Bull Micral 60,
Intel 80286
The Intel 80286 (also marketed as the iAPX 286 and often called Intel 286) is a 16-bit microprocessor that was introduced on February 1, 1982. It was the first 8086-based CPU with separate, non- multiplexed address and data buses and also the f ...
at 6 MHz,
PC-AT compatible
* 1986 : Bull Micral 35, Intel 80286 at 8 MHz
* 1987 : Bull Micral 40, Intel 80286 at 8 MHz
* 1988 : Bull Micral 45, Intel 80286 at 12 MHz
* 1988 : Bull Micral 65, Intel 80286 at 12 MHz
* 1988 : Bull Micral 75,
Intel 80386
The Intel 386, originally released as the 80386 and later renamed i386, is the third-generation x86 architecture microprocessor from Intel. It was the first 32-bit computing, 32-bit processor in the line, making it a significant evolution in ...
at 16 MHz
* 1988 : Bull Micral Attaché, Intel 8086 at 9.54 MHz, portable
* 1989 : Bull Micral 200, Intel 80286 at 12 MHz
* 1989 : Bull Micral 600, Intel 80386 at 25 MHz
* Unknown year : Bull Micral 500, Intel 80386 at 20 MHz,
Micro Channel bus
In 1989, Bull bought
Zenith Data Systems
Zenith Data Systems Corporation (ZDS) was an American computer systems manufacturing company active from 1979 to 1996. It was originally a division of the Zenith Radio Company (later Zenith Electronics), after they had purchased the Heath Com ...
, starting to release PC compatibles under the brand ''Zenith''.
See also
*
History of computing hardware (1960s–present)
The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state electronics, solid-state devices such as transistors and then integrated circuit (IC) chips. Around 1953 to 1959, discrete transistors ...
*
History of personal computers
The history of the personal computer as a mass-market consumer electronic device began with the microcomputer revolution of the 1970s. A personal computer is one intended for interactive individual use, as opposed to a mainframe computer whe ...
*
Intellec
The Intellec computers were a series of early microcomputers Intel produced in the 1970s as a development platform for their processors. The Intellec computers were among the first microcomputers ever sold, predating the Altair 8800 by at leas ...
*
List of early microcomputers
*
Portal laptop computer
*
Computing for All
The Computing for All plan (''Plan Informatique pour Tous'' – ''IPT'') was a French government plan to introduce computers to the country's 11 million pupils. A second goal was to support national industry. It followed several introductory comput ...
, a French government plan to introduce computers to the country's pupils
References
External links
Gernelle and Truong* François Gernelle
LA NAISSANCE DU PREMIER MICRO-ORDINATEUR : LE MICRAL N ("The birth of the first microcomputer: the Micral N")' Proceedings of the second symposium on the history of computing (CNAM, Paris, 1990)
* François Gernelle
Communication sur les choix architecturaux et technologiques qui ont présidé à la conception du "Micral" Premier micro-ordinateur au monde' Proceedings of the fifth symposium on the history of computing (Toulouse, 1998)
* French patent FR2216883 (number INPI: 73 03 553), German patent DE2404886, Dutch Patent NL7401328, Japanese patent JP50117333 (inventor François Gernelle
RECHNER, INSBESONDERE FUER REALZEIT-ANWENDUNG(August 8, 1974)
* French patent FR2216884(number INPI: 7303552), German patent DE2404887, Dutch patent NL7401271, Japanese patent JP50117327 (inventor François Gernelle)
KANAL FUER DEN INFORMATIONSAUSTAUSCH ZWISCHEN EINEM RECHNER UND SCHNELLEN PERIPHEREN EINHEITEN(August 8, 1974)
* : Data processing system, specially for real-time applications
* {{US patent, 4040026: Channel for exchanging information between a computer and rapid peripheral units (''pile-canal'')
MICRAL documentationat bitsavers.org
Early microcomputers
Groupe Bull
8-bit computers
History of computing in France
Computer science education in France
Computing for All
Computers designed in France