UNICOS is a range of
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, an ...
and after it
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
(OS) variants developed by
Cray for its
supercomputers. UNICOS is the successor of the
Cray Operating System
The Cray Operating System (COS) is a Cray Research operating system for its now-discontinued Cray-1 (1976) and Cray X-MP supercomputers. It succeeded the Chippewa Operating System (shipped with earlier Control Data Corporation CDC 6000 series a ...
(COS). It provides network
clustering and source code
compatibility layer
In software engineering, a compatibility layer is an interface that allows binaries for a legacy or foreign system to run on a host system. This translates system calls for the foreign system into native system calls for the host system. With so ...
s for some other Unixes. UNICOS was originally introduced in 1985 with the
Cray-2
The Cray-2 is a supercomputer with four vector processors made by Cray Research starting in 1985. At 1.9 GFLOPS peak performance, it was the fastest machine in the world when it was released, replacing the Cray X-MP in that spot. It was, i ...
system and later ported to other Cray models. The original UNICOS was based on
UNIX 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 ...
Release 2, and had many
Berkeley Software Distribution (BSD) features (e.g.,
computer networking
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
and
file system enhancements) added to it.
Development
CX-OS was the original name given to what is now UNICOS. This was a prototype system which ran on a
Cray X-MP in 1984 before the Cray-2 port. It was used to demonstrate the feasibility of using
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, an ...
on a supercomputer system, before Cray-2 hardware was available.
The operating system revamp was part of a larger movement inside Cray Research to modernize their corporate software: including rewriting their most important
Fortran compiler (cft to cft77) in a higher-level language (
Pascal) with more modern optimizations and vectorizations.
As a migration path for existing COS customers wishing to transition to UNICOS, a Guest Operating System (GOS) capability was introduced into COS. The only guest OS that was ever supported was UNICOS. A COS batch job would be submitted to start up UNICOS, which would then run as a subsystem under COS, using a subset of the systems CPUs, memory, and peripheral devices. The UNICOS that ran under GOS was exactly the same as when it ran stand-alone: the difference was that the
kernel
Kernel may refer to:
Computing
* Kernel (operating system), the central component of most operating systems
* Kernel (image processing), a matrix used for image convolution
* Compute kernel, in GPGPU programming
* Kernel method, in machine learn ...
would make certain low-level hardware requests through the COS GOS hook, rather than directly to the hardware.
One of the sites that ran very early versions of UNICOS was
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial Research and development, research and scientific developm ...
, where Unix pioneers including
Dennis Ritchie ported parts of their
Eighth Edition Unix (including
STREAMS input/output
In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Inputs are the signals ...
(I/O)) to UNICOS. They also experimented with a guest facility within UNICOS, allowing the stand-alone version of the OS to host itself.
Releases
Cray released several different OSs under the name UNICOS, including:
#''UNICOS'': the original Cray Unix, based on System V. Used on the
Cray-1,
Cray-2
The Cray-2 is a supercomputer with four vector processors made by Cray Research starting in 1985. At 1.9 GFLOPS peak performance, it was the fastest machine in the world when it was released, replacing the Cray X-MP in that spot. It was, i ...
,
X-MP,
Y-MP,
C90, etc.
#''UNICOS MAX'': a
Mach-based
microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...
used on the
T3D's processing elements, together with UNICOS on the host Y-MP or C90 system.
#''UNICOS/mk'': a ''serverized'' version of UNICOS using the
Chorus microkernel
In computer science, a microkernel (often abbreviated as μ-kernel) is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system (OS). These mechanisms include low-level address space management, ...
to make a
distributed operating system
A distributed operating system is system software over a collection of independent software, networked, communicating, and physically separate computational nodes. They handle jobs which are serviced by multiple CPUs. Each individual node holds a ...
. Used on the
T3E. This was the last Cray OS really based on UNICOS sources, as the following products were based on different sources and simply used the "UNICOS" name.
#''UNICOS/mp'': not derived from UNICOS, but based on
IRIX 6.5. Used on the
X1.
#''UNICOS/lc'': not derived from UNICOS, but based on
SUSE Linux. Used on the
XT3,
XT4 and
XT5. UNICOS/lc 1.x comprises a combination of
##the compute elements run the
Catamount
The cougar (''Puma concolor'') is a large cat native to the Americas. Its range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mammal in the Western Hemisphere. ...
microkernel (which itself is based on
Cougaar)
##the service elements run SUSE Linux
#''Cray Linux Environment'' (CLE): from release 2.1 onward, UNICOS/lc is now called Cray Linux Environment
##the compute elements run
Compute Node Linux (CNL) (which is a customized
Linux kernel)
##the service elements run
SUSE Linux Enterprise Server
See also
*
Scientific Linux
Scientific Linux (SL) was a Linux distribution produced by Fermilab, CERN, DESY and by ETH Zurich. It is a free and open-source operating system based on Red Hat Enterprise Linux.
This product is derived from the free and open-source software ma ...
, a
Linux distribution by
Fermilab
Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been opera ...
and
CERN
*
Rocks Cluster Distribution
Rocks Cluster Distribution (originally NPACI Rocks) is a Linux distribution intended for high-performance computing (HPC) clusters. It was started by National Partnership for Advanced Computational Infrastructure and the San Diego Supercompute ...
, a Linux distribution for supercomputers
References
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*
{{Microkernel
1984 software
Cray software
Linux distributions
Microkernel-based operating systems
Microkernels
Supercomputer operating systems
Unix distributions
UNIX System V