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Multics (Acronyme of MULTiplexed Information and Computing Service ) is the name of a Operating system from which UNIX derives directly and, via this last, of very many current systems (* BSD, Mac OS X, Solaris, HP-UX, AIX, etc Linux being a clone).

Conceived in 1965, it was used until in 2000.

History

Creation

Multics was conceived jointly by the MIT, the Laboratoires Beautiful and General Electric. The Bell laboratories withdrew project in 1969 then General Electric sold in 1970 its data-processing department in Honeywell. MIT finished only the project. Multics was then marketed by Honeywell.

The name UNIX was invented by reaction vis-a-vis slowness and to the difficulties which marked the development of Multics.

Decline

In the middle of the Years 1980, Honeywell put an end to the development of the operating system. They sold the data-processing section in Bull, which put an end to the production of material for MULTICS. Thus, all the sites using Multics started to change operating system.

Features

Multics was written in language PL/1.

Heritage of CTSS

Multics borrowed many concepts from the operating system CTSS, from which it derives. He exerted itself a major influence on UNIX.

CTSS, Multics inherited:

the concept of time-sharing, which makes it possible several users to use at the same time the machine;
the system of invites of order, at the origin of the Shell of today;
the principle of the Word processing, allowing a typography of quality per computer.

Contributions of Multics

One of the objectives of Multics was to allow control by a final distant. To ensure the integrity of the data and safety between the simultaneous users, Multics introduced the concept of rings (Boxing rings).

Multics supported the segmentation of the memory, the virtual Memory, the implementation of languages high level, the plurality of the languages, with an high level of safety.

The Filesystem of Multics is at the origin of the modern filesystems: it was arranged hierarchically, supported the long file names, the removable bonds symbolic systems, peripherals, etc

Ambition of Multics

The objective of Multics was to provide an operating system which can accommodate several hundreds of simultaneous users. It was thought whereas a waiter could meet the needs for the population of all the zone of Boston, for example. The overall spirit was to imitate the operation of the distribution of electricity or of the Téléphone: the customer connects himself to a network which meets its needs (contrary to the model which seems to be imposed at present: the dispersion of work stations connected in network).

Success of Multics

Multics did not have much business success, but he was appreciated in the scientific world and always has his admirors. Large companies like the NSA, Ford and General Motors used Multics.

In France, Multics was popular in the university world in the Années 1980 insofar as the obligatory equipment were to be Bull.

Bull, partner of Honeywell, sold configurations on 31 sites to succeed IRISES 80 of CII. Bull developed the operating system GCOS 6 derived from Multics. It was a financial success (and technique), with hundreds of customers in the Eighties and Nineties.

Always in France, in 1973, Multics was taught at the University Paris VI - Jussieu within " the Institute of Programming, DEA of Programming and Opérationnelle" Research;. The first conversations (Cat) between two terminals Teleprinters one in Billerica close to Boston and the other with the head office of Honewell-Bull (64 Avenue Gambetta in Paris 20) were carried out under Multics in May 1974 and took place daily to exchange on the progress report of the development of DPS7 (GCOS-64 or GCOS7). The mainframes used on the two sides were GE-645, advanced version of the GE-635.

The last waiter in the world using Multics, with the Canadian Department off National Defense, was extinct the October 31st 2000.

Multics is now much less famous and popular that the operating system conceived by that which was one of its developers in the Bell laboratories, Kenneth Thompson. When the Bell laboratories withdrew Multics project, Thompson was indeed without task, and conceived for itself reduced Multics, that it called for this reason UNICS: UNiplexed Information and Computing Service.

See too

External bond

Multicians, history of MULTICS
Source code of MULTICS

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