The SGI IRIS series of terminals and

workstation A workstation is a special computer designed for technical or computational science, scientific applications. Intended primarily to be used by a single user, they are commonly connected to a local area network and run multi-user operating syste ...

s from

Silicon Graphics Silicon Graphics, Inc. (stylized as SiliconGraphics before 1999, later rebranded SGI, historically known as Silicon Graphics Computer Systems or SGCS) was an American high-performance computing manufacturer, producing computer hardware and soft ...

was produced in the 1980s and 1990s. IRIS is an acronym for Integrated Raster Imaging System.

Overview

68000

Silicon Graphics Computer Systems' first product, shipped in November 1983, was the IRIS 1000, a terminal with hardware-accelerated 3D graphics based on the Geometry Engine developed by

Jim Clark James Clark (4 March 1936 – 7 April 1968) was a British racing driver from Scotland, who competed in Formula One from to . Clark won two Formula One World Drivers' Championship titles with Lotus, and—at the time of his death—held the ...

and

Marc Hannah Marc Hannah (born October 13, 1956) is an American electrical engineer and computer graphics designer. He is one of the co-founders of Silicon Graphics Inc. Early life and education Hannah was born on October 13, 1956, in Chicago, Illinois. Han ...

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

. As a terminal, it was not intended for standalone use, and was instead attached to a

VAX-11 The VAX-11 is a discontinued family of 32-bit superminicomputers, running the Virtual Address eXtension (VAX) instruction set architecture (ISA), developed and manufactured by Digital Equipment Corporation (DEC). Development began in 1976. In ...

running

VAX/VMS OpenVMS, often referred to as just VMS, is a multi-user, multiprocessing and virtual memory-based operating system. It is designed to support time-sharing, batch processing, transaction processing and workstation applications. Customers using Op ...

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 ...

. It was soon followed by the IRIS 1200, another terminal with a larger

backplane A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect s ...

, before the IRIS 1400 emerged as SGCS's first standalone workstation in 1984. The processor used in these early systems, the 'PM1', was a variant of the SUN (Stanford UNiversity) processor, and sported a

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

(or 68010) clocked at 8 MHz. With the IRIS 2000 series (released in 1985) came SGCS's first internally-designed processor, with a Motorola 68010 running at 10 MHz. The final Motorola 68000-based series, the 3000s released in 1986, were built around a 68020 running at 16 MHz. These systems ran the GL1, then GL2 operating system, a predecessor of the

IRIX IRIX (, ) is a discontinued operating system developed by Silicon Graphics (SGI) to run on the company's proprietary MIPS architecture, MIPS workstations and servers. It is based on UNIX System V with Berkeley Software Distribution, BSD extensio ...

operating system, which is based on

UniSoft UniSoft Corporation is an American software developer established in 1981, originally focused on the development of Unix ports for various computer architectures. Based in Millbrae, California, it now builds standardization and conformance te ...

UniPlus

System V Unix 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 ...

. GL2 uses a proprietary (and highly rudimentary) windowing system named mex (Multiple EXposure).

MIPS

Beginning in 1987, SGCS began selling workstations with MIPS

RISC In electronics and computer science, a reduced instruction set computer (RISC) is a computer architecture designed to simplify the individual instructions given to the computer to accomplish tasks. Compared to the instructions given to a comp ...

processors rather than the Motorola 680x0. These new systems adopted a different numbering scheme, with the prefix '4D/' followed by a two-to-three digit number. The first of these systems was the 4D/60 'Professional IRIS', sporting a MIPS R2300 clocked at 8 MHz in a unique 'twin-tower' case, with the cardcage being within the larger tower on the left, and the power supply and drives being kept within the smaller tower on the right. The right tower could come in different heights to support larger quantities of storage. Like the IRIS 1000 series which preceded it, the 4D/60 did not use an internally designed processor board, instead using a generic MIPS systems board (likewise, the earliest versions of the new operating system for the MIPS-based workstations, dubbed '4D1', was largely derived from MIPS' own

RISC/OS RISC/os is a discontinued UNIX operating system developed by MIPS Computer Systems, Inc. from 1985 to 1992, for their computer workstations and servers, including such models as the MIPS M/120 server and MIPS Magnum workstation. It was also kno ...

). In 1988, SGCS superseded the Professional IRIS line with the higher-end Power IRIS line (specializing in

Symmetric Multi-Processing Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ...

, and so-named for its proprietary POWERpath architecture), and the lower-end Personal IRIS line. The Power IRIS systems (later dubbed "PowerSeries") came in a number of configurations, with anywhere between 1 and 8 processors and coming in either a twin-tower chassis akin to the Professional IRIS, a mini-fridge sized desk-side chassis (code-named 'Diehard'), or a full rack-sized chassis (code-named 'Predator'). One could determine the processor count of a Power IRIS system from its model number - the second digit would directly indicate the number of CPUs, so a 4D/210 would have one processor, a 4D/340 would have 4 processors, etc. The Power IRIS series was ultimately eclipsed, first by the 64-bit

MIPS R4000 The R4000 is a microprocessor developed by MIPS Computer Systems that implements the MIPS III instruction set architecture (ISA). Officially announced on 1 October 1991, it was one of the first 64-bit microprocessors and the first MIPS III imple ...

-based IRIS Crimson, and then by the POWERpath-2 based

Onyx Onyx is a typically black-and-white banded variety of agate, a silicate mineral. The bands can also be monochromatic with alternating light and dark bands. ''Sardonyx'' is a variety with red to brown bands alternated with black or white bands. ...

and Challenge series. The Personal IRIS line consisted of four main models - the 4D/20, /25, /30, and /35. The /20 and /25 were both released in 1988, with the /30 and /35 debuting in 1990. With an entry price of £10,300, the Personal IRIS was Silicon Graphics' cheapest workstation. The 4D/35 would later be cost-reduced into the

IRIS Indigo The Indigo, introduced as the IRIS Indigo, is a line of workstation computers developed and manufactured by Silicon Graphics, Inc. (SGI). SGI first announced the system in July 1991. The Indigo is one of the most capable graphics workstations ...

, released in 1991, which was so architecturally similar to the 4D/35 that it shared the same Internal Processor ID (IP12) in software. Beginning in late 1992 with the release of the Indigo² and Challenge, the 'IRIS' prefix would be dropped from the names of all future systems, as well as the '4D/' model numbers. The '4D1' operating system, which from version 4D1-3 onwards was officially referred to as IRIX 4D1 (IRIX being a portmanteau of 'IRIS' and 'UNIX), would be re-branded as simply '

' beginning in version 5, as well. However, all future MIPS-based systems released by Silicon Graphics would still use 'IRIS' as the default hostname, ending with the Tezro in 2003.

Human Interface Devices

A unifying feature across all IRISes – 68K, Professional, Personal, PowerSeries, Indigo, Crimson, and – is a proprietary serial-based keyboard/mouse protocol. Earlier machines use either a DE-15 (68K, Professional, PowerSeries) or DE-9 (4D/20, /25) connector, with the later machines (4D/30, /35, Indigo, Crimson, Onyx) using a mini DIN-6 which is easy to confuse with a standard PS/2 connector. One must take care not to insert an IRIS keyboard into a

PS/2 port The PS/2 port is a 6-pin mini-DIN connector used for connecting Computer keyboard, keyboards and computer mouse, mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it ...

or vice versa, as the voltage levels used in the two protocols are incompatible and may result in damage to the keyboard, computer, or both. An easy method to determine if a Silicon Graphics keyboard is PS/2 or not is to check whether or not the mouse plugs in to the keyboard - the IRIS protocol, similar to

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

Apple Desktop Bus Apple Desktop Bus (ADB) is a proprietary bit-serial peripheral bus connecting low-speed devices to computers. It was introduced on the Apple IIGS in 1986 as a way to support low-cost devices like keyboards and mice, enabling them to be conn ...

and Sun's own serial keyboard/mouse protocol, daisy-chains the mouse and keyboard together.

References

External links

IRIS 1000
{{Silicon Graphics 68k-based computers