Multics 832 entries
29 Aug 2017

Glossary - O

Glossary of Multics acronyms and terms. Entries by Tom Van Vleck ([THVV]) unless noted.


Index| A| B| C| P| C| D| E| F| G| H| I| J| K| L| M| N| O| P| Q| R| S| T| U| V| W| X|
object segment
Segment containing executable machine instructions. (need more. should point to article with the format)

octal
Counting in base 8. On a 36-bit word machine, this is the natural way to express numbers. Core dumps are printed in octal. Another place octal shows up is in octal escape sequences for terminal input: to enter an underscore, for example, on a terminal that lacks the _ character, you can type \137.

ONERA
[Daniel Bois] Multics site: Office National d'Etudes et de Recherches Aéronautiques. Had two sites: Centre d'Etudes et de Recherche de Toulouse [ONERA-CERT] in Toulouse, France, doing airspace research (1983-88); and another in Châtillon, near Paris (1985-88), installed near a Cray Y-MP and Multics was running the software we developed here at Bull for front-ending the Cray. I called it "The marriage of the Muscle and the Brain" !!!

Online T&D
Online Test and Diagnostics. Allows boxes to be isolated from a running system and tested. CPU and memory were first. I/O testing was not done until the mid 80s.

Operations Unit
[BSG] Or OU. That portion of the 6180 CPU ("Operations Frame" on the 645) that maintains and manages the conventional registers (A, Q, Exponent, index registers), and performs arithmetic (including floating point) and logical operations upon them. The OU contains no registers for addresses and does not issue requests for memory access -- that is all done for it by the Control Unit. The port logic, as instructed by the CU, tells it when data is available, stored, or ready to be stored. Having no interaction with address preparation, it is the least Multics-specific of the processor components. The OU does, however, involve logic to ensure that registers values are ready when needed and not before! As the 6180 is entirely asynchronous, all this facilitates OU operation overlapped with logically "succeeding" CU instruction preparation.

operator
Unsung heroes. Computer operators at many sites worked long and hard to keep big machines running and users happy. This is a fast-vanishing profession. See also pl1_operators_ and terminal operators.

Opus
System proposed by CISL in 1986 to follow on after Multics. Eventually canceled by Bull. Officially known as NOS/VS3 or HVS release 3. This group was managed by Michael Tague.

Orange Book
Standards document produced by the NCSC, titled Department of Defense Trusted Computer System Evaluation Criteria, DOD 5200.28-STD, December 1985. Describes levels of security for computer systems. Multician Roger Schell was the main driver behind this document.

ORAS
Operations Reporting and Accounting System. A large application developed by SofTech, Waltham MA, under contract to GM corporate in the mid 70s. ORAS was a huge spreadsheet application that summarized all of GM's business.

Orion
1970s Honeywell codename for a processor in the ADP architecture.

OU
(1) Multics site: Oakland University [OU]. Rochester, MI, near Detroit. 1978-1990. See Oakland site history.

(2) The Operations Unit.

outer module
I/O module intended for user stream attachment. Both ios_ and iox_ supported attaching user I/O names to DIMs that ran in the user ring and might call on other outer modules or on ring-0 DIMs.

Overlap Project
[Wren McMains] MIT social-science project, a continuation of the Cambridge Project, which paid to keep the IBM 7094 going at IPC when Multics was late in the 1960s.