Xenix
Information about Xenix
) Xenix under Bochs | |
| Company/ developer: | Microsoft |
| OS family: | Unix |
| Source model: | Closed source |
| Latest stable release: | 2.3.4 / 1989 |
| Kernel type: | Monolithic kernel |
| Working state: | Historic |
History
)
Microsoft Xenix 1.00 on 5¼-inch floppy disk
Xenix was Microsoft's version of Unix intended for use on microcomputers; since Microsoft was not able to license the "UNIX" name itself, they gave it an original name. The -ix ending follows a convention used by many other Unix-like operating systems.
Microsoft purchased a license for Version 7 Unix from AT&T in 1979, and announced on August 25, 1980 that it would make it available for the 16-bit microcomputer market.
Xenix varied from its 7th Edition origins by incorporating elements from BSD, and soon possessed the most widely installed base of any Unix flavour due to the popularity of the inexpensive x86 processor.
Microsoft did not sell Xenix directly to end users; instead, they licensed it to software OEMs such as Intel, Tandy, Altos and SCO, who then ported it to their own proprietary computer architectures. Microsoft Xenix originally ran on the PDP-11; the first port was for the Zilog Z8001 16-bit processor. Altos shipped a version for their computers early in 1982, Tandy Corporation shipped TRS-XENIX for their 68000-based systems in January 1983, and SCO released their port to the Intel 8086 processor in September 1983. A port to the 68000-based Apple Lisa also existed. At the time, Xenix was based on AT&T's UNIX System III.
Version 2.0 of Xenix was released in 1985 and was based on UNIX System V. An update numbered 2.1.1 added support for the Intel 80286 processor. Subsequent releases improved System V compatibility.
When Microsoft entered into an agreement with IBM to develop OS/2, it lost interest in promoting Xenix. In 1987 Microsoft transferred ownership of Xenix to SCO in an agreement that left Microsoft owning 25% of SCO. When Microsoft eventually lost interest in OS/2 as well, it based its further high-end strategy on Windows NT.
In 1987, SCO ported Xenix to the 386 processor, a 32-bit chip. Xenix 2.3.1 introduced support for i386, SCSI and TCP/IP.
Microsoft continued to use Xenix internally, submitting a patch to support functionality in UNIX to AT&T in 1987, which trickled down to the code base of both Xenix and SCO UNIX. Microsoft is said to have used Xenix on Sun workstations and VAX minicomputers extensively within their company as late as 1992.[1]
In the late 1980s, Xenix was, according to The Design and Implementation of the 4.3BSD UNIX Operating System, "probably the most widespread version of the UNIX operating system, according to the number of machines on which it runs".[2]
SCO branched Xenix into SCO UNIX in 1989. In the meantime, AT&T completed its merge of Xenix, BSD, SunOS and System V into System V Release 4. SCO UNIX was still based on System V Release 3, but had most features of Release 4. The last version of Xenix itself was 2.3.4.
Trusted Xenix
Trusted Xenix was a variant developed by Trusted Information Systems which incorporated the Bell-LaPadula model of multilevel security, and had a multilevel secure interface for the STU-III secure communications device (that is, an STU-III connection would only be made available to applications running at the same privilege level as the key loaded in the STU-III). It was evaluated by formal methods and achieved a B2 security rating under the NSA's Trusted Computer System Evaluation Criteria—the second highest rating ever achieved by an evaluated operating system. Version 2.0 was released in January 1991, version 3.0 in April 1992, and version 4.0 in September 1993. It was still in use at least as of 1995.References
1. ^ Terry Lambert (2000-11-07). "[news://200011062350.QAA25774_usr08.primenet.com@ns.sol.net Re: Microsoft Source (fwd)]". [news://sol.lists.freebsd.chat sol.lists.freebsd.chat]. (Google Groups). Retrieved on 2006-10-25.
2. ^ Leffler, Samuel J.; et al. (October 1989). The Design and Implementation of the 4.3BSD UNIX Operating System. Addison-Wesley, page 7. ISBN 0-201-06196-1.
2. ^ Leffler, Samuel J.; et al. (October 1989). The Design and Implementation of the 4.3BSD UNIX Operating System. Addison-Wesley, page 7. ISBN 0-201-06196-1.
See also
External links
- Line-art print advertisement for Microsoft Xenix, circa 1980
- Photograph and description of circa-1988 Xenix product box
- Tandy Images for Download
Unix and Unix-like operating systems |
|---|
| A/UX AIX BSD FreeBSD GNU HP-UX IRIX Linux Mac OS X NetBSD NEXTSTEP OpenBSD Plan 9 QNX Research Unix SCO OpenServer SINIX Solaris System V Tru64 Xenix |
The term software company could be applied to: a) a company that produces software, distributes software from a third party, or provides services such as custom software development.
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A software developer is a person who is concerned with one or more facets of the software development process, a somewhat broader scope of computer programming or a specialty of project managing.
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Microsoft Corporation
Public (NASDAQ: MSFT )
Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States
Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States
Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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Unix (officially trademarked as UNIX®) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy.
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Closed source is a term for software whose license does not meet the definition of open-source software. Generally, it means only the binaries of a computer program are distributed and the license provides no access to the program's source code, rendering modifications to the
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A monolithic kernel is a kernel architecture where the entire kernel is run in kernel space in supervisor mode. In common with other architectures (microkernel, hybrid kernels), the kernel defines a high-level virtual interface over computer hardware, with a set of primitives or
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Unix (officially trademarked as UNIX®) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy.
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An operating system (OS) is the software that manages the sharing of the resources of a computer. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the
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Microsoft Corporation
Public (NASDAQ: MSFT )
Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States
Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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Public (NASDAQ: MSFT )
Founded Albuquerque, New Mexico, USA (April 4 1975)[1]
Headquarters Redmond, Washington, United States
Key people Bill Gates, Co-founder and Executive Chairman ;
Paul Allen, Co-founder ;
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AT&T Inc.
Public (NYSE: T )
Founded 1983[1]
Headquarters San Antonio, Texas, USA
Key people Randall L. Stephenson, Chairman/CEO; Richard Lindner, CFO
Industry Telecommunications
Products Wireless, Telephone, Internet, Television
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Public (NYSE: T )
Founded 1983[1]
Headquarters San Antonio, Texas, USA
Key people Randall L. Stephenson, Chairman/CEO; Richard Lindner, CFO
Industry Telecommunications
Products Wireless, Telephone, Internet, Television
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Santa Cruz Operation (SCO) was a software company based in Santa Cruz, California that was best known for selling three Unix variants for Intel x86 processors: Xenix, SCO UNIX (later known as SCO OpenServer), and UnixWare.
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SCO OpenServer, previously SCO UNIX and SCO Open Desktop (SCO ODT), is a closed source version of the Unix computer operating system developed by Santa Cruz Operation (SCO) and now maintained by the SCO Group.
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Unices by Bell
Research Unix
V6 (1975)
V7 (1979)
V8 (1985)
V9 (1986)
V10 (1989)
CB Unix
PWB/UNIX Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7
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Research Unix
V6 (1975)
V7 (1979)
V8 (1985)
V9 (1986)
V10 (1989)
CB Unix
PWB/UNIX Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7
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16-bit integers, memory addresses, or other data units are those that are at most 16 bits (2 octets) wide. Also, 16-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
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Berkeley Software Distribution (BSD, sometimes called Berkeley Unix) is the UNIX derivative distributed by the University of California, Berkeley, starting in the 1970s.
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The generic term x86 refers to the "CISC" type instruction set of the most commercially successful CPU architecture[1] in the history of personal computing, used in processors from Intel, AMD, VIA, and others.
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porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed (e.g. different CPU, operating system, or third party library).
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computer architecture is the conceptual design and fundamental operational structure of a computer system. It is a blueprint and functional description of requirements (especially speeds and interconnections) and design implementations for the various parts of a computer —
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The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corp. in the 1970s and 1980s. The PDP-11 was a successor to DEC's PDP-8 computer in the PDP series of computers. It had several uniquely innovative features, and was easier to program than its predecessors.
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porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed (e.g. different CPU, operating system, or third party library).
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Zilog, NASDAQ: ZILG often seen as ZiLOG (the official company denotation since 1998), is a manufacturer of 8-bit, 16-bit, 24-bit, and 32-bit CPUs, and is most famous for its Intel 8080-compatible Z80 series.
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The Z8001 was the version of the 16-bit Zilog Z8000 which offered 7-bit segment registers, yielding an 8 megabyte address space. However, it was found the hardware would fail explosively, so the version was discontinued.
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External links
- http://www.
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central processing unit (CPU), or sometimes simply processor, is the component in a digital computer capable of executing a program.(Knott 1974) It interprets computer program instructions and processes data.
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Acer Inc.
Public (TSEC: 2353)
Founded 1976
Founder Stan Shih et al.
Headquarters Taipei, Taiwan
Industry Computer
Products Laptop, Desktop Computers, Servers, IT services
Revenue $11.
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Public (TSEC: 2353)
Founded 1976
Founder Stan Shih et al.
Headquarters Taipei, Taiwan
Industry Computer
Products Laptop, Desktop Computers, Servers, IT services
Revenue $11.
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The Motorola 68000 is a CISC microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor Products Sector). As the first member of the successful 32-bit m68k family of microprocessors, it is generally software forward compatible with the
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Intel 8086
Central processing unit
Produced: From 1978-79 to 1982
Manufacturer: Intel
CPU Speeds: 4.
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Central processing unit
Produced: From 1978-79 to 1982
Manufacturer: Intel
CPU Speeds: 4.
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Apple Lisa was a personal computer designed at Apple Computer during the early 1980s.
The Lisa project was started at Apple in 1978 and evolved into a project to design a powerful personal computer with a graphical user interface (GUI) that would be targeted toward business
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The Lisa project was started at Apple in 1978 and evolved into a project to design a powerful personal computer with a graphical user interface (GUI) that would be targeted toward business
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UNIX System III (sometimes called System 3) was a version of the Unix operating system released by AT&T's Unix Support Group (USG). It was first released outside of Bell Labs in 1982. It was an amalgam of various AT&T Unixes: PWB/UNIX 2.0, CB UNIX 3.0, UNIX/TS 3.0.
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Unix System V, commonly abbreviated SysV and rarely called System 5, was one of the 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, termed Releases 1, 2, 3 and 4.
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286
Central processing unit
An Intel 80286 Microprocessor
Produced: From 1982 to 1986
Common Manufacturers:
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Central processing unit
An Intel 80286 Microprocessor
Produced: From 1982 to 1986
Common Manufacturers:
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