Ultrix
Encyclopedia
Ultrix was the brand name of Digital Equipment Corporation
's (DEC) native Unix
systems. While ultrix is the Latin
word for avenger, the name was chosen solely for its sound.
and PDP-11
(Programmable Data Processor) systems. Later DEC computers, such as their VAX
systems, were also popular platforms on which to run Unix; the first port to VAX, UNIX/32V
, was finished in 1978 (the VAX was only released in October 1977). However DEC supplied their own proprietary operating system, VMS
, for a long time before they acknowledged Unix.
Absolutely key to bringing Unix to inside the company, DEC's Unix Engineering Group (UEG) was started by Bill Munson with Jerry Brenner and Fred Canter, both from DEC's premier Customer Service Engineering group, Bill Shannon (from Case Western Reserve University
), and Armando Stettner (from Bell Labs
). Other later members of UEG included Joel Magid, Bill Doll, and Jim Barclay recruited from DEC's various marketing and product management groups.
The UEG team, under Canter's direction, released V7M, a modified version of Unix 7th Edition
(q.v.).
and device driver support initially on UNIX/32V but quickly moved to concentrate on working with the University of California, Berkeley
's 4BSD
. Berkeley's Bill Joy
came to New Hampshire to work with Shannon and Stettner to wrap up a new BSD release, incorporating the UEG CPU support and drivers, and to do some last minute development and testing on other configurations available at DEC's facilities. As an aside, the three brought up a final test version on the main VAX used by the VMS development group. No comments were heard from the VMS developers whose terminals greeted them the next morning with a Unix login prompt. UEG's machine was the first to run the new Unix, labeled 4.5BSD as was the tape Bill Joy took with him. The thinking was that 5BSD would be the next version - university lawyers thought it would be better to call it 4.1BSD. After the completion of 4.1BSD, Bill Joy left Berkeley to work at Sun Microsystems
. Bill Shannon later moved from New Hampshire to join him. Armando Stettner stayed at DEC and later conceived of and started the Ultrix project.
As an aside, DEC UEG's main VAX, named decvax, was also one of the central nodes in the UUCP
and Usenet
network. It was the first system to link, in real time for email and Usenet news article, the east and west coasts of the US, Duke University
(duke) and UC Berkeley (ucbvax). Later, after some compression capability was added to netnews, decvax was linked with Europe (Vrije Universiteit
, Amsterdam) and then Australia (University of Melbourne
), making calls at least twice per day each.
Shortly after IBM
announced plans for a native UNIX product, Stettner, having advocated a DEC UNIX product several times in the past, suggested to Bill Doll, a marketing manager, during a hallway conversation that it was finally time for DEC to make a native VAX Unix product available to its customers. A proposal was made to Bill Munson who later presented the idea to Ken Olsen
. It was said that Olsen grabbed a Unix license plate, slapped it on someone's chest and said let's do it. Thus began Ultrix.
, and was released in June 1984. Ultrix-32 was primarily the brainchild of Armando Stettner. Its purpose was to provide a DEC-supported native Unix for VAX. It also incorporated several modifications and scripts from Usenet/UUCP experience gained while running decvax. Later, Ultrix-32 incorporated support for DECnet
and other proprietary DEC protocols such as LAT
. It did not support VAXclustering
. Given Western Electric
/AT&T Unix licensing, DEC (and others) were restricted to selling binary-only licenses. A significant part of the engineering work was in making the systems relatively flexible and configurable despite their binary-only nature.
After Ultrix-32 completed its first phase of customer beta trials, Armando moved to the West Coast to help Steve Bourne start up DEC's Workstation Systems Engineering organization, an advanced development group focusing on graphics and workstations. From there, he went on to conceive of, write its first charter, and help in the formation of the Open Software Foundation
. Armando then worked in a very small cross organizational group from which spawned DEC's first RISC workstation product, the MIPS-based DECstation 3100.
In the end, DEC provided its Ultrix-branded native Unix operating systems on three platforms: PDP-11
minicomputers (where Ultrix was one of many available operating systems from DEC), VAX
-based computers (where Ultrix was one of two primary OS choices) and the DECstation
workstations and DECsystem
servers (where Ultrix was the only OS choice offered). Note that the DECstation systems used MIPS processors and predate the much later Alpha
-based systems.
The V7m product was later renamed to Ultrix-11 to establish the family with Ultrix-32, but as the PDP-11 faded from view Ultrix-32 became known simply as Ultrix. When the MIPS versions of Ultrix was released, the VAX and MIPS versions were referred to as VAX/ULTRIX and RISC/ULTRIX respectively. Much engineering emphasis was placed on supportability and reliable operations including continued work on CPU and device driver support (which was, for the most part, also sent to UC Berkeley), hardware failure support and recovery with enhancement to error message text, documentation, and general work at both the kernel and systems program levels. Later Ultrix-32 incorporated some features from 4.3BSD and optionally included DECnet
and SNA in addition to the standard TCP/IP, and both the SMTP and DEC's Mail-11
protocols.
Notably, Ultrix implemented the inter-process communication
(IPC) facilities found in System V (named pipe
s, messages
, semaphores
, and shared memory
). While the converged Unix from the Sun and AT&T alliance
(that spawned the Open Software Foundation
or OSF), released late 1986, put BSD features into System V, DEC took the best from System V and added it to a BSD base.
Originally, on the VAX workstations, Ultrix-32 had a desktop environment
called UWS, Ultrix Workstation Software, which was based on a version of the X Window System
. Later, the widespread version 11 of the X Window System
(X11) was added, using a look and feel called DECwindows that was devised in order to mimic the look and feel of the UWS system. Eventually DECwindows also provided the Motif
look and feel.
Ultrix ran on multiprocessor
systems from both the VAX and DECsystem families. Ultrix-32 supported SCSI
disks and tapes and also proprietary Digital Storage Systems Interconnect
and CI peripherals employing DEC's Mass Storage Control Protocol
, although lacking the OpenVMS distributed lock manager it did not support concurrent access from multiple Ultrix systems. DEC also released a combination hardware and software product named Prestoserv which accellerated NFS file serving to allow better performance for diskless workstations to communicate to a file serving Ultrix host. The kernel supported symmetric multiprocessing
while not being fully multithreaded
based upon pre-Ultrix work by Armando Stettner and earlier work by George Goble at Purdue University. As such, there was liberal use of locking and some tasks could only be done by a particular CPUs (e.g. the processing of interrupt
s). This was not uncommon in other SMP implementations of that time (e.g. SunOS
). Also, Ultrix was slow to support many then new or emerging Unix system capabilities found on competing Unix systems (e.g. it never supported shared libraries or dynamically linked executables; delay in implementing bind, 4.3BSD system calls and libraries especially the math libraries; etc.) and suffered from some problems, most notably file system integrity issues (having never picked up the 4.3BSD filesystem and fixes).
3100 workstation. Later, DEC replaced Ultrix as its Unix offering with OSF/1 for the Alpha
, ending Unix development on the MIPS and VAX platforms. OSF/1 had previously shipped in a version for the MIPS architecture in 1991, but was not considered or advertised as a mature product. OSF/1 had a Mach-based kernel with many of the features missing from Ultrix. Again, the UEG (by now the Ultrix Engineering Group) worked at making the new OSF/1-based Digital Unix run well on DEC hardware, with the reliability and maintainability that people came to expect from DEC operating systems.
The last major release of Ultrix was version 4.5 in 1995, which supported all previously supported DECstations and VAXen. There were some subsequent Y2K
patches.
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
's (DEC) native Unix
Unix
Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...
systems. While ultrix is the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word for avenger, the name was chosen solely for its sound.
History
The initial development of Unix occurred on DEC equipment, notably DEC PDP-7PDP-7
The DEC PDP-7 is a minicomputer produced by Digital Equipment Corporation. Introduced in 1965, it was the first to use their Flip-Chip technology. With a cost of only $72,000 USD, it was cheap but powerful by the standards of the time. The PDP-7 was the third of Digital's 18-bit machines, with...
and PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
(Programmable Data Processor) systems. Later DEC computers, such as their VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
systems, were also popular platforms on which to run Unix; the first port to VAX, UNIX/32V
UNIX/32V
UNIX/32V was an early version of the Unix operating system from Bell Laboratories, released in June 1979. 32V was a direct port of the PDP-11 Seventh Edition Unix to the DEC VAX architecture....
, was finished in 1978 (the VAX was only released in October 1977). However DEC supplied their own proprietary operating system, VMS
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
, for a long time before they acknowledged Unix.
Absolutely key to bringing Unix to inside the company, DEC's Unix Engineering Group (UEG) was started by Bill Munson with Jerry Brenner and Fred Canter, both from DEC's premier Customer Service Engineering group, Bill Shannon (from Case Western Reserve University
Case Western Reserve University
Case Western Reserve University is a private research university located in Cleveland, Ohio, USA...
), and Armando Stettner (from Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
). Other later members of UEG included Joel Magid, Bill Doll, and Jim Barclay recruited from DEC's various marketing and product management groups.
The UEG team, under Canter's direction, released V7M, a modified version of Unix 7th Edition
Version 7 Unix
Seventh Edition Unix, also called Version 7 Unix, Version 7 or just V7, was an important early release of the Unix operating system. V7, released in 1979, was the last Bell Laboratories release to see widespread distribution before the commercialization of Unix by AT&T in the early 1980s...
(q.v.).
BSD
Shannon and Stettner worked on low-level CPUCentral processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
and device driver support initially on UNIX/32V but quickly moved to concentrate on working with the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
's 4BSD
Berkeley Software Distribution
Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995...
. Berkeley's Bill Joy
Bill Joy
William Nelson Joy , commonly known as Bill Joy, is an American computer scientist. Joy co-founded Sun Microsystems in 1982 along with Vinod Khosla, Scott McNealy and Andy Bechtolsheim, and served as chief scientist at the company until 2003...
came to New Hampshire to work with Shannon and Stettner to wrap up a new BSD release, incorporating the UEG CPU support and drivers, and to do some last minute development and testing on other configurations available at DEC's facilities. As an aside, the three brought up a final test version on the main VAX used by the VMS development group. No comments were heard from the VMS developers whose terminals greeted them the next morning with a Unix login prompt. UEG's machine was the first to run the new Unix, labeled 4.5BSD as was the tape Bill Joy took with him. The thinking was that 5BSD would be the next version - university lawyers thought it would be better to call it 4.1BSD. After the completion of 4.1BSD, Bill Joy left Berkeley to work at Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
. Bill Shannon later moved from New Hampshire to join him. Armando Stettner stayed at DEC and later conceived of and started the Ultrix project.
As an aside, DEC UEG's main VAX, named decvax, was also one of the central nodes in the UUCP
UUCP
UUCP is an abbreviation for Unix-to-Unix Copy. The term generally refers to a suite of computer programs and protocols allowing remote execution of commands and transfer of files, email and netnews between computers. Specifically, a command named uucp is one of the programs in the suite; it...
and Usenet
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
network. It was the first system to link, in real time for email and Usenet news article, the east and west coasts of the US, Duke University
Duke University
Duke University is a private research university located in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present day town of Trinity in 1838, the school moved to Durham in 1892. In 1924, tobacco industrialist James B...
(duke) and UC Berkeley (ucbvax). Later, after some compression capability was added to netnews, decvax was linked with Europe (Vrije Universiteit
Vrije Universiteit
The Vrije Universiteit is a university in Amsterdam, Netherlands. The Dutch name is often abbreviated as VU and in English the university uses the name "VU University". The university is located on a compact urban campus in the southern part of Amsterdam in the Buitenveldert district...
, Amsterdam) and then Australia (University of Melbourne
University of Melbourne
The University of Melbourne is a public university located in Melbourne, Victoria. Founded in 1853, it is the second oldest university in Australia and the oldest in Victoria...
), making calls at least twice per day each.
Shortly after IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
announced plans for a native UNIX product, Stettner, having advocated a DEC UNIX product several times in the past, suggested to Bill Doll, a marketing manager, during a hallway conversation that it was finally time for DEC to make a native VAX Unix product available to its customers. A proposal was made to Bill Munson who later presented the idea to Ken Olsen
Ken Olsen
Kenneth Harry Olsen was an American engineer who co-founded Digital Equipment Corporation in 1957 with colleague Harlan Anderson.-Background:...
. It was said that Olsen grabbed a Unix license plate, slapped it on someone's chest and said let's do it. Thus began Ultrix.
V7m
DEC's first native UNIX product was V7M (for modified) or V7M11 for the PDP-11 and was based on version of UNIX 7th Edition from Bell Labs. V7M, developed by DEC's original Unix Engineering Group (UEG), Fred Canter, Jerry Brenner, Armando Stettner, Bill Burns, Mary Anne Cacciola and Bill Munson - but the work of primarily Fred and Jerry. V7M contained many fixes to the kernel including support for separate instruction and data spaces, significant work for hardware error recovery, and many device drivers. Much work was put into producing a release that would reliably bootstrap from many tape drives or disk drives. V7M was well respected in the Unix community. UEG evolved into the group that later developed Ultrix.First release of Ultrix
The first native VAX UNIX product from DEC was Ultrix-32, based on 4.2BSD with some non-kernel features from System VUNIX System V
Unix System V, commonly abbreviated SysV , is one of the first commercial versions of the Unix operating system. It was originally developed by American Telephone & Telegraph and first released in 1983. Four major versions of System V were released, termed Releases 1, 2, 3 and 4...
, and was released in June 1984. Ultrix-32 was primarily the brainchild of Armando Stettner. Its purpose was to provide a DEC-supported native Unix for VAX. It also incorporated several modifications and scripts from Usenet/UUCP experience gained while running decvax. Later, Ultrix-32 incorporated support for DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
and other proprietary DEC protocols such as LAT
Local Area Transport
Local Area Transport is a non-routable networking technology developed by Digital Equipment Corporation to provide connection between the DECserver 90, 100, 200, 300, 500, 700 and DECserver 900 terminal servers and Digital's VAX and Alpha and MIPS_architecture host computers via Ethernet, giving...
. It did not support VAXclustering
VMScluster
A VMScluster is a computer cluster involving a group of computers running the OpenVMS operating system. Whereas tightly coupled multiprocessor systems run a single copy of the operating system, a VMScluster is loosely coupled: each machine runs its own copy of OpenVMS, but the disk storage, lock...
. Given Western Electric
Western Electric
Western Electric Company was an American electrical engineering company, the manufacturing arm of AT&T from 1881 to 1995. It was the scene of a number of technological innovations and also some seminal developments in industrial management...
/AT&T Unix licensing, DEC (and others) were restricted to selling binary-only licenses. A significant part of the engineering work was in making the systems relatively flexible and configurable despite their binary-only nature.
After Ultrix-32 completed its first phase of customer beta trials, Armando moved to the West Coast to help Steve Bourne start up DEC's Workstation Systems Engineering organization, an advanced development group focusing on graphics and workstations. From there, he went on to conceive of, write its first charter, and help in the formation of the Open Software Foundation
Open Software Foundation
The Open Software Foundation was a not-for-profit organization founded in 1988 under the U.S. National Cooperative Research Act of 1984 to create an open standard for an implementation of the UNIX operating system.-History:...
. Armando then worked in a very small cross organizational group from which spawned DEC's first RISC workstation product, the MIPS-based DECstation 3100.
In the end, DEC provided its Ultrix-branded native Unix operating systems on three platforms: PDP-11
PDP-11
The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...
minicomputers (where Ultrix was one of many available operating systems from DEC), VAX
VAX
VAX was an instruction set architecture developed by Digital Equipment Corporation in the mid-1970s. A 32-bit complex instruction set computer ISA, it was designed to extend or replace DEC's various Programmed Data Processor ISAs...
-based computers (where Ultrix was one of two primary OS choices) and the DECstation
DECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...
workstations and DECsystem
DECsystem
DECsystem was a line of server computers from Digital Equipment Corporation. They were based on MIPS architecture processors and ran DEC's version of the UNIX operating system, called Ultrix...
servers (where Ultrix was the only OS choice offered). Note that the DECstation systems used MIPS processors and predate the much later Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
-based systems.
The V7m product was later renamed to Ultrix-11 to establish the family with Ultrix-32, but as the PDP-11 faded from view Ultrix-32 became known simply as Ultrix. When the MIPS versions of Ultrix was released, the VAX and MIPS versions were referred to as VAX/ULTRIX and RISC/ULTRIX respectively. Much engineering emphasis was placed on supportability and reliable operations including continued work on CPU and device driver support (which was, for the most part, also sent to UC Berkeley), hardware failure support and recovery with enhancement to error message text, documentation, and general work at both the kernel and systems program levels. Later Ultrix-32 incorporated some features from 4.3BSD and optionally included DECnet
DECnet
DECnet is a suite of network protocols created by Digital Equipment Corporation, originally released in 1975 in order to connect two PDP-11 minicomputers. It evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s...
and SNA in addition to the standard TCP/IP, and both the SMTP and DEC's Mail-11
Mail-11
Mail-11 was the native email transport protocol used by Digital Equipment Corporation's VMS operating system, and supported by several other DEC operating systems such as Ultrix.It normally used the DECnet networking system as opposed to TCP/IP....
protocols.
Notably, Ultrix implemented the inter-process communication
Inter-process communication
In computing, Inter-process communication is a set of methods for the exchange of data among multiple threads in one or more processes. Processes may be running on one or more computers connected by a network. IPC methods are divided into methods for message passing, synchronization, shared...
(IPC) facilities found in System V (named pipe
Named pipe
In computing, a named pipe is an extension to the traditional pipe concept on Unix and Unix-like systems, and is one of the methods of inter-process communication. The concept is also found in Microsoft Windows, although the semantics differ substantially...
s, messages
Message passing
Message passing in computer science is a form of communication used in parallel computing, object-oriented programming, and interprocess communication. In this model, processes or objects can send and receive messages to other processes...
, semaphores
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type that provides a simple but useful abstraction for controlling access by multiple processes to a common resource in a parallel programming environment....
, and shared memory
Shared memory
In computing, shared memory is memory that may be simultaneously accessed by multiple programs with an intent to provide communication among them or avoid redundant copies. Depending on context, programs may run on a single processor or on multiple separate processors...
). While the converged Unix from the Sun and AT&T alliance
Unix wars
The Unix wars were the struggles between vendors of the Unix computer operating system in the late 1980s and early 1990s to set the standard for Unix thenceforth.- Origins :...
(that spawned the Open Software Foundation
Open Software Foundation
The Open Software Foundation was a not-for-profit organization founded in 1988 under the U.S. National Cooperative Research Act of 1984 to create an open standard for an implementation of the UNIX operating system.-History:...
or OSF), released late 1986, put BSD features into System V, DEC took the best from System V and added it to a BSD base.
Originally, on the VAX workstations, Ultrix-32 had a desktop environment
Desktop environment
In graphical computing, a desktop environment commonly refers to a style of graphical user interface derived from the desktop metaphor that is seen on most modern personal computers. These GUIs help the user in easily accessing, configuring, and modifying many important and frequently accessed...
called UWS, Ultrix Workstation Software, which was based on a version of the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
. Later, the widespread version 11 of the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
(X11) was added, using a look and feel called DECwindows that was devised in order to mimic the look and feel of the UWS system. Eventually DECwindows also provided the Motif
Motif (widget toolkit)
In computing, Motif refers to both a graphical user interface specification and the widget toolkit for building applications that follow that specification under the X Window System on Unix and other POSIX-compliant systems. It emerged in the 1980s as Unix workstations were on the rise, as a...
look and feel.
Ultrix ran on multiprocessor
Multiprocessor
Computer system having two or more processing units each sharing main memory and peripherals, in order to simultaneously process programs.Sometimes the term Multiprocessor is confused with the term Multiprocessing....
systems from both the VAX and DECsystem families. Ultrix-32 supported SCSI
SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
disks and tapes and also proprietary Digital Storage Systems Interconnect
Digital Storage Systems Interconnect
The Digital Storage Systems Interconnect is a bus developed by Digital Equipment Corporation for connecting storage devices and clustering VAX systems and support was extended to MIPS based DECsystem and later to Alpha processor based AlphaServer systems.It was introduced in 1988 and has a...
and CI peripherals employing DEC's Mass Storage Control Protocol
Mass Storage Control Protocol
The Mass Storage Control Protocol was a protocol designed by Digital Equipment Corporation of Maynard, Massachusetts for the purposes of controlling their high-end mass storage options....
, although lacking the OpenVMS distributed lock manager it did not support concurrent access from multiple Ultrix systems. DEC also released a combination hardware and software product named Prestoserv which accellerated NFS file serving to allow better performance for diskless workstations to communicate to a file serving Ultrix host. The kernel supported symmetric multiprocessing
Symmetric multiprocessing
In computing, symmetric multiprocessing involves a multiprocessor computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture...
while not being fully multithreaded
Thread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
based upon pre-Ultrix work by Armando Stettner and earlier work by George Goble at Purdue University. As such, there was liberal use of locking and some tasks could only be done by a particular CPUs (e.g. the processing of interrupt
Interrupt
In computing, an interrupt is an asynchronous signal indicating the need for attention or a synchronous event in software indicating the need for a change in execution....
s). This was not uncommon in other SMP implementations of that time (e.g. SunOS
SunOS
SunOS is a version of the Unix operating system developed by Sun Microsystems for their workstation and server computer systems. The SunOS name is usually only used to refer to versions 1.0 to 4.1.4 of SunOS...
). Also, Ultrix was slow to support many then new or emerging Unix system capabilities found on competing Unix systems (e.g. it never supported shared libraries or dynamically linked executables; delay in implementing bind, 4.3BSD system calls and libraries especially the math libraries; etc.) and suffered from some problems, most notably file system integrity issues (having never picked up the 4.3BSD filesystem and fixes).
Last release
As part of its commitment to the OSF, Armando Stettner went to DEC's Cambridge Research Labs to work on the port of OSF/1 to DEC's RISC-based DECstationDECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...
3100 workstation. Later, DEC replaced Ultrix as its Unix offering with OSF/1 for the Alpha
DEC Alpha
Alpha, originally known as Alpha AXP, is a 64-bit reduced instruction set computer instruction set architecture developed by Digital Equipment Corporation , designed to replace the 32-bit VAX complex instruction set computer ISA and its implementations. Alpha was implemented in microprocessors...
, ending Unix development on the MIPS and VAX platforms. OSF/1 had previously shipped in a version for the MIPS architecture in 1991, but was not considered or advertised as a mature product. OSF/1 had a Mach-based kernel with many of the features missing from Ultrix. Again, the UEG (by now the Ultrix Engineering Group) worked at making the new OSF/1-based Digital Unix run well on DEC hardware, with the reliability and maintainability that people came to expect from DEC operating systems.
The last major release of Ultrix was version 4.5 in 1995, which supported all previously supported DECstations and VAXen. There were some subsequent Y2K
Year 2000 problem
The Year 2000 problem was a problem for both digital and non-digital documentation and data storage situations which resulted from the practice of abbreviating a four-digit year to two digits.In computer programs, the practice of representing the year with two...
patches.
See also
- Comparison of BSD operating systemsComparison of BSD operating systemsThere are a number of Unix-like operating systems based on or descended from the Berkeley Software Distribution series of Unix variants. The three most notable descendants in current use are FreeBSD, OpenBSD, and NetBSD, which are all derived from 386BSD and 4.4BSD-Lite, by various routes...
- Ultrix/UWS Release Notes V4.1, AA-ME85D-TE
- Ultrix-32 Supplementary Documents, AA-MF06A-TE
- The Little Gray Book: An ULTRIX Primer, AA-MG64B-TE
- Guide to Installing Ultrix and UWS, AA-PBL0G-TE
External links
- [ftp://ftp.digital.com/pub/DEC/dec-faq/ultrix Ultrix FAQ]
- Info on Ultrix from OSdata (version as of Jan 11 2006)
- [ftp://ifctfvax.harhan.org/pub/UNIX/thirdparty/Ultrix-32/sources/ Ultrix 2.0, 4.2, and 4.3 source code]
- Ultrix system manuals