Try Our Apps


The saddest words


aos in Technology

1. /aws/ (East Coast), /ay-os/ (West Coast) A PDP-10 instruction that took any memory location and added 1 to it. AOS meant "Add One and do not Skip". Why, you may ask, does the "S" stand for "do not Skip" rather than for "Skip"? Ah, here was a beloved piece of PDP-10 folklore. There were eight such instructions: AOSE added 1 and then skipped the next instruction if the result was Equal to zero; AOSG added 1 and then skipped if the result was Greater than 0; AOSN added 1 and then skipped if the result was Not 0; AOSA added 1 and then skipped Always; and so on. Just plain AOS didn't say when to skip, so it never skipped.
For similar reasons, AOJ meant "Add One and do not Jump". Even more bizarre, SKIP meant "do not SKIP"! If you wanted to skip the next instruction, you had to say "SKIPA". Likewise, JUMP meant "do not JUMP"; the unconditional form was JUMPA. However, hackers never did this. By some quirk of the 10's design, the JRST (Jump and ReSTore flag with no flag specified) was actually faster and so was invariably used. Such were the perverse mysteries of assembler programming.
2. /A-O-S/ or /A-os/ A Multics-derived operating system supported at one time by Data General.
A spoof of the standard AOS system administrator's manual ("How to Load and Generate your AOS System") was created, issued a part number, and circulated as photocopy folklore; it was called "How to Goad and Levitate your CHAOS System".
3. Algebraic Operating System, in reference to those calculators which use infix operators instead of postfix notation.
[Jargon File]

The Free On-line Dictionary of Computing, © Denis Howe 2010
Cite This Source
Examples from the Web for aos
Historical Examples
Related Abbreviations for aos


Academic Orthopaedic Society
acquisition of signal
American Otological Society
The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Cite This Source

Word of the Day

Word Value for aos

Scrabble Words With Friends

Nearby words for aos