Data General AOS (an abbreviation for Advanced Operating System) was the name of a family of

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

s for

Data General Data General Corporation was one of the first minicomputer firms of the late 1960s. Three of the four founders were former employees of Digital Equipment Corporation (DEC). Their first product, 1969's Data General Nova, was a 16-bit minicompu ...

16-bit 16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two mos ...

Eclipse An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ce ...

C, M, and S

minicomputer A minicomputer, or colloquially mini, is a class of smaller general purpose computers that developed in the mid-1960s and sold at a much lower price than mainframe and mid-size computers from IBM and its direct competitors. In a 1970 survey, ...

s, followed by AOS/VS and AOS/RT32 (1980) and later

AOS/VS II AOS/VS II is a discontinued operating system for the Data General 32-bit MV/Eclipse computers. Overview The AOS/VS II operating system was released in 1988 and was originally to be simply rev 8.00 of the AOS/VS operating system. However, it int ...

(1988) for the 32-bit Eclipse MV line.

Overview

AOS/VS exploited the 8- ring protection architecture of the Eclipse MV hardware with ring 7 being the least privileged and ring 0 being the most privileged. The AOS/VS kernel ran in ring 0 and used ring-1 addresses for data structures related to virtual address translations. Ring 2 was unused and reserved for future use by the kernel. The Agent, which performed much of the system call validation for the AOS/VS kernel, as well as some I/O buffering and many compatibility functions, ran in ring 3 of each process. Ring 4 was used by various D.G. products such as the INFOS II

DBMS In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases span ...

. Rings 5 and 6 were reserved for use by user programs but rarely used except for large software such as the MV/UX inner-ring emulator and

Oracle An oracle is a person or agency considered to provide wise and insightful counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. As such, it is a form of divination. Description The wor ...

which used ring 5. All user programs ran in ring 7. The AOS software was far more advanced than competing

PDP-11 The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of all models were so ...

operating systems. 16-bit AOS applications ran natively under AOS/VS and AOS/VS II on the 32-bit Eclipse MV line. AOS/VS (Advanced Operating System/Virtual Storage) was the most commonly used DG software product, and included a

command-line interpreter A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive command (computing), commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invokin ...

(CLI) allowing for complex scripting, DUMP/LOAD, and other custom components. The 16-bit version of the CLI is famous for including an

Easter egg Easter eggs, also called Paschal eggs, are eggs that are decorated for the Christian feast of Easter, which celebrates the resurrection of Jesus. As such, Easter eggs are common during the season of Eastertide (Easter season). The oldest trad ...

meant to honor Xyzzy (which was pronounced "magic"). This was the internal code name of what externally became known as the AOS/VS 32-bit operating system. A user typing in the

command Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards ...

" xyzzy" would get back a response from the CLI of "Nothing Happens". When a

32-bit In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in 32- bit units. Compared to smaller bit widths, 32-bit computers can perform large calcula ...

version of the CLI became available under

, the same command instead reported "Twice As Much Happens". A modified version of System V.2

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

called MV/UX hosted under AOS/VS was also available. A modified version of

System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

Unix called DG/UX was made for the Eclipse MV line and later the

88K The 88000 (m88k for short) is a RISC instruction set architecture developed by Motorola during the 1980s. The MC88100 arrived on the market in 1988, some two years after the competing SPARC and MIPS. Due to the late start and extensive delays re ...

and x86 AViiON machines. The AOS and AOS/VS kernels were written entirely in assembly language. Almost all of the AOS and AOS/VS utilities included in the operating system releases were written in DG/L a variant of the ALGOL/60 programming language. Initially, AOS/VS utilities closely tracked AOS source development. As AOS/VS matured, many DG-supplied utilities were rewritten to take advantage of the 32-bit address space and reduce dependencies on assembly language, often resulting in substantial increases in functionality, performance and reliability compared with their AOS ancestors.

Session

**** Atari S/W Development HCD1 / BATCH OUTPUT FILE ****

AOS/VS  3.07 / EXEC  3.07	19-JAN-84	10:11:01	
QPRI=254	SEQ=31324
INPUT FILE -- :UDD:SYSTEMS:850:?031.CLI.004.JOB (WILL BE DELETED AFTER PROCESSING)
LIST FILE  -- :QUEUE:NORDIN.LIST.31324

--------
LAST MESSAGE CHANGE	12-JAN-84	16:06:08

		Atari S/W Development System HCD1

Backup schedule (system shut down): Saturday  21-Jan-84  9:30-11:30am

Refer to HELP *COMMANDS, HELP *PSEUDO, HELP, APHELP, and ?MHELP.

Refer to DISP FUNC in SED for list of default function key commands.

--------
LAST PREVIOUS LOGON	19-JAN-84	10:09:45
* searchlist :UDD:NORDIN:UTIL :UDD:NORDIN:LINKS :C :UTIL :

AOS/VS CLI   REV 03.03.00.00	19-JAN-84	10:11:05
Ý SEARCHLIST :UDD:SYSTEMS:UTIL,:UDD:NORDIN:UTIL,:UDD:NORDIN:LINKS,:C,:UTIL,:
Ý DIRECTORY :UDD:SYSTEMS:850
Ý DEFACL SYSTEMS,OWARE,A.JOE,OWARE,A.OLIVIA,OWARE,ARKEN,OWARE,BLOTCKY,OWARE,NORDIN,OWARE,TITTSLER,OWARE,FOWKES,OWARE
Ý CAMAC R850AMAC H=R850AMAC.OBJ L=R850AMAC.PRN R=F SL=132 


ATARI CAMAC Assembler Ver  1.0A
Copyright 1981 ATARI Inc.

Enter source file name and options

d:R850AMAC  h=d:R850AMAC.OBJ l=d:R850AMAC.PRN R=F SL=132           

  Pass 1 - Reading D1:R850AMAC.   
  Pass 2 - Reading D1:R850AMAC.   

  no ERRORs,  669 Labels, $67E8 free.
�

ATARI CAMAC Assembler Ver  1.0A
Copyright 1981 ATARI Inc.

Enter source file name and options



Ý 
Ý 
END OF FILE
AOS/VS CLI   TERMINATING	19-JAN-84	10:12:06

PROCESS 42 TERMINATED 
ELAPSED TIME  0:01:06
(OTHER JOBS, SAME USERNAME)
USER 'NORDIN' LOGGED OFF 	19-JAN-84	10:12:07


****
* LIST FILE EMPTY, WILL NOT BE PRINTED
****

References

Proprietary operating systems Data General {{Operating-system-stub

Overview

Session

See also

References