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 and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s for

Data General Data General Corporation was an early minicomputer firm formed in 1968. 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 minicomputer intended to ...

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 ...

Eclipse An eclipse is an astronomical event which 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 ...

C, M, and S

minicomputer A minicomputer, or colloquially mini, is a type of general-purpose computer mostly developed from the mid-1960s, built significantly smaller and sold at a much lower price than mainframe computers . By 21st century-standards however, a mini is ...

s, followed by AOS/VS and AOS/RT32 (1980) and later AOS/VS II (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 or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and ana ...

. 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 thing considered to provide insight, wise counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. If done through occultic means, it is a form of divination. Descript ...

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 originally sold by Digital Equipment Corporation (DEC) from 1970 into the late 1990s, one of a set of products in the Programmed Data Processor (PDP) series. In total, around 600,000 PDP-11s of a ...

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 interface (CLI) is a means of interacting with software via commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternativ ...

(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 holiday of Easter, which celebrates the resurrection of Jesus. As such, Easter eggs are commonly used during the season of Eastertide (Easter season). The ...

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 (Unix), a Unix command * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on A ...

" 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 a maximum of 32- bit units. Compared to smaller bit widths, 32-bit computers can perform la ...

version of the CLI became available under AOS/VS II, 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, multi-user 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 DG/UX is a discontinued Unix operating system developed by Data General for its Eclipse MV minicomputer line, and later the AViiON workstation and server line (both Motorola 88000 and Intel IA-32-based variants). Overview DG/UX 1.00, released in ...

was made for the Eclipse MV line and later the 88K and

x86 x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel, based on the 8086 microprocessor and its 8-bit-external-bus variant, the 8088. Th ...

AViiON machines. The AOS and AOS/VS kernels were written entirely in

assembly language In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence bet ...

. 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