Multics today

Where can I get a Multics account today?

The last Multics site shut down as of 31 Oct 2000. Discussion of resurrecting Multics in alt.os.multics has not yet led to a revival of the system. If you want a Multics account, join the revival effort.

I'd like to see some Multics source. How?

Bull HN has made the entire source of Multics available "for any purpose and without fee" at MIT as of November 2007. Source for a few programs is available at this site, cross-referenced to the Glossary.

Could Multics be ported to a modern micro?

Probably. Several projects were started to try this in the 80s, as described on the Multics History page. None of these projects finished. Porting Multics would be a big job, and the final product would need further development to match the current state of the art. Paul Green says, "I think it would be easier to try 'improving' existing technology than to resurrect Multics itself."

Could an emulator be written for a Multics CPU?

Yes. See below for Harry Reed's and Michael Mondy's projects, which run on Windows, Mac OS, and Unix.

News Events

See Multics History for historical narrative and the Multics Chronology for historical dates.

new December 2014: The Annual Computer Security Applications Conference (ACSAC) 2014 presented a Distinguished Practitioner Keynote Panel titled "Multics: Before, During, After". Olin Sibert moderated: Roger Schell, Tom Van Vleck, and Steve Lipner were the panelists. The panel talked about the 50-year influence of Multics on computer science and on subsequent systems.

new November 2014: Harry Reed's simulator for the Multics CPU reached a major milestone on Saturday 08 November. The SIMH-based simulator booted Multics MR 12.5, came to operator command level, entered admin mode, created a small PL/I program, compiled and executed it, and shut down. The simulator has also generated a new Multics System Tape boot image, and booted it.

June 2014: Michael Pandolfo has begun the Multics50 Project to prepare for a celebration of the 50th annversary of Multics in 2015 by organizing a volunteer force to

Contact him to participate.

May 2014: MIT held a 50th anniversary celebration of Project MAC/ LCS/ CSAIL in Cambridge, MA on May 28 & 29, 2014. There was also an associated Multicians' reunion event on May 29. A story with photos and links to videos is online.

Dec 2013: Harry Reed's emulator has progressed to a point where it can run about 30M instruction cycles of the T&D tape.

Mar 2013: Michael Mondy has been working on a Multics CPU simulator for several years. His simulator is able to load a simulated boot tape and run for many instructions before taking a fault in init_empty_root.

Nov 2012: Harry Reed has started a project to create a software simulator for the Multics CPU based on Bob Supnik's SIMH. The purpose of this project is to create an open source simulator reproducing in sufficient detail the function and capabilities of the Honeywell/Bull DPS-8/M processor with the ultimate goal of resurrecting Multics. Harry is interested in finding volunteers to code, debug, document, test, etc. People who understand the workings of the Multics CPU are especially welcome. For information on this project, use the "Wiki" tab on the SourceForge page linked above.

Nov 2007: Open Source for Multics is hosted at MIT, courtesy of Bull HN. It is available "for any purpose and without fee" provided that the copyright notice and historical background are preserved in all copies.

Oct 2000: The Canadian Dept of National Defence machine at MCHQ (Halifax, NS) shut down at 17:08Z on 10/30/00. This is thought to be the last machine running.

Jul 2000: The CGI (formerly Perigon (formerly ACTC)) machine shut down on July 7, 2000.