Micral

Micral N

Micral is a series of microcomputers produced by the French company Réalisation d'Études Électroniques (R2E), beginning with the Micral N in early 1973.

According to the Computer History Museum, the Micral N was the earliest commercial, non-kit personal computer based on a microprocessor (in this case, the Intel 8008).^[1]

R2E founder André Truong Trong Thi (EFREI degree, Paris), a French immigrant from Vietnam, asked Frenchman François Gernelle to develop the Micral N computer for the Institut National de la Recherche Agronomique (INRA), starting in June 1972.^[2][3][4] Alain Perrier of INRA was looking for a computer for process control in his crop evapotranspiration measurements.^[5][6] 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 minicomputers. 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. It does not aim to be an universal mini-computer."^[7]

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-based MIC 01 monitor and the ASMIC 01 assembler,^[7] 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 bus, 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 instead of core memory. The Micral N could support parallel and serial input/output. It had 8 levels of interrupt and a stack. The computer was programmed with punched tape, and used a teleprinter or modem for I/O. The front panel console was optional, offering customers the option of designing their own console to match a particular application.^[7] 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, was advertised in the March 1974 issue of QST, an amateur radio magazine.^[8]

Indeed, INRA was originally planning to use PDP-8 computers for process control, but the Micral N could do the same for a fifth of the cost. An 8-inch floppy disk reader was added to the Micral in December 1973, following a command of the Commissariat à l'Energie Atomique. 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 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.

Following the April 1974 introduction of the Intel 8080, R2E introduced the second and third Micral models, 8080-based at 1 MHz, the Micral G and Micral S.

In November 1975, R2E signed Warner & Swasey Company 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.^[9] 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.^[10]

Micral P2

Some time after the July 1976 introduction of the Zilog Z80, came the Z80-based Micral CZ. The 8080-based Micral C, an intelligent CRT terminal designed for word processing and automatic typesetting, was introduced in July 1977.^[11] 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.^[12] The Micral V Portable (1978) could run FORTRAN and assembler under the Sysmic operating system, or BAL.^[13] The original Sysmic operating system was renamed Prologue in 1978. Interestingly, Prologue was able to perform real-time multitasking, and was a multi-user system. R2E offered CP/M for the Micral C in 1979.^[14] Later Micrals used the Intel 8088. The last Micral designed by François Gernelle was the 9020.^[15] In 1981, R2E was bought by Groupe Bull. Starting with the Bull Micral 30, which could use both Prologue and MS-DOS, Groupe Bull transformed the Micral computers into a line of PC compatibles. François Gernelle left Bull in 1983.

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 was a programmer for the Micral.^[16][17] Kahn later headed Borland which released Turbo Pascal and Sidekick in 1983.

See also

• André Truong Trong Thi
• History of computing hardware (1960s–present)
• History of personal computers
• List of early microcomputers

References

External links

Wikimedia Commons has media related to Micral.

• Gernelle and Truong
• A picture of the Front panel of Micral-N
• 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)

• U.S. Patent 3,974,480: Data processing system, specially for real-time applications
• U.S. Patent 4,040,026: Channel for exchanging information between a computer and rapid peripheral units (pile-canal)
• MICRAL documentation at bitsavers.org