Data General AOS
Data General AOS (an abbreviation for Advanced Operating System[1]) was the name of a family of operating systems for Data General 16-bit Eclipse C, M, and S minicomputers, followed by AOS/VS and AOS/RT32[2] (1980) and later AOS/VS II (1988) for the 32-bit Eclipse MV line.
| Developer | Data General |
|---|---|
| Working state | Discontinued |
| Source model | Closed-source |
| Platforms | Data General 16-bit Eclipse C, M, and S minicomputers and 32-bit Eclipse MV line |
| Default user interface | Command-line interpreter |
| License | Proprietary commercial software |
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. 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 which used ring 5. All user programs ran in ring 7.
The AOS software was far more advanced than competing PDP-11 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 (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 taken directly from the Colossal Cave Adventure game. A user typing in the command "xyzzy" would get back a response from the CLI of "Nothing Happens". When a 32-bit 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 called MV/UX hosted under AOS/VS was also available. A modified version of System V Unix called DG/UX was made for the Eclipse MV line and later the 88K 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 variants of the PL/I 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
****
See also
References
- https://archive.org/details/bitsavers_dgsoftwarebraryFileEditorUMApr77raw_1324483
- Hoard, Bruce. "Computerworld Nov 22, 1982". Computerworld. IDG. Retrieved 2011-09-28.