SGI IRIS: Difference between revisions

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 [[James H. Clark|Jim Clark]] and [[Marc Hannah]] at [[Stanford University]]. As a terminal, it was not intended for standalone use, and was instead attached to a [[VAX-11]] running [[VAX/VMS]] or [[Unix]]. It was soon followed by the IRIS 1200, another terminal with a larger [[backplane]],<ref>{{cite web|url=https://www.typewritten.org/Articles/SGI/5001-020-001-3.pdf|title=IRIS Terminal Guide V1.3|publisher=SGI|date=1984|access-date=2021-12-24}}</ref> before the IRIS 1400 emerged as SGCS's first standalone workstation in 1984.<ref>{{Cite web|title=IRIX Info Page|url=https://umips.net/irix/index.html|access-date=2021-07-11|website=umips.net}}</ref> The processor used in these early systems, the 'PM1', was a variant of the SUN (Stanford UNiversity) processor, and sported a [[Motorola 68000]] (or 68010) clocked at 8Mhz8 MHz. With the IRIS 2000 series (released in 1985) came SGCS's first internally-designed processor, with a Motorola 68010 running at 10&nbsp; MHz. The final Motorola 68000-based series, the 3000s released in 1986, were built around a 68020 running at 16Mhz16 MHz.<ref>{{cite web|url=https://hardware.majix.org/computers/sgi/iptable.shtml|title=SGI IP Table|access-date=2023-12-16}}</ref> These systems ran the GL1, then GL2 operating system, a predecessor of the [[IRIX]] operating system, which is based on [[UniSoft]] UniPlus [[System V Unix]].<ref>{{cite web|url=https://ryan.thoryk.com/sgi/irix_versions.html|title=History of IRIX|author=Ryan Thoryk|date=2021-10-07|access-date=2021-12-25}}</ref> GL2 uses a proprietary (and highly rudimentary) [[windowing system]] named [[MEX (windowing system)|mex]] (Multiple EXposure).<ref>{{cite web|url=https://bitsavers.org/pdf/sgi/iris/007-1103-010_IRIS_Programming_Tutorial_v1.0_1986.pdf|title=IRIS Programming Tutorial V1.0|date=1986|publisher=SGI|access-date=2021-12-25|website=Bitsavers}}</ref>

Beginning in 1987, SGCS began selling workstations with [[MIPS architecture|MIPS]] [[RISC]] processors rather than the Motorola 68000680x0. 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&nbsp; 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 [[IRIX|'4D1']], was largely derived from MIPS' own [[MIPS RISC/os|RISC/OS]]).

In 1988, SGCS superseded the Professional IRIS line with the higher-end PowerSeriesPower IRIS line (specializing in [[symmetric multiprocessing|Symmetric Multi-Processing]], and so-named for its proprietary POWERpath architecture), and the lower-end Personal IRIS line. The PowerSeriesPower 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 PowerSeriesPower 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 PowerSeriesPower IRIS series was ultimately eclipsed, first by the 64-bit [[MIPS R4000]]-based [[SGI Crimson|IRIS Crimson]], and then by the POWERpath-2 based [[SGI Onyx|Onyx]] and [[SGI Challenge|Challenge]] series.<ref>{{cite web|url=https://www.sgistuff.net/hardware/systems/powerseries.html|title=PowerSeries|access-date=2023-12-16}}</ref>

Beginning in late 1992 with the release of the [[SGI Indigo² and Challenge M|Indigo²]] and [[SGI Challenge|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 '[[IRIX]]' beginning in version 35, as well. However, all future MIPS-based systems released by Silicon Graphics would still use 'IRIS' as the default hostname, ending with the [[SGI Tezro|Tezro]] in 2003.

A unifying feature across all IRISes – 68K, Professional, Personal, PowerSeries, Indigo, Crimson, and {{Tooltip|Onyx|The Onyx, unlike its contemporaries the Indigo and Crimson, was never marketed or branded as part of the IRIS 4D series, but shared the same keyboard/mouse protocol and industrial design language as the IRIS 4D machines.}} – 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]] 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 Inc.|Apple]]'s [[Apple Desktop Bus]] and Sun's own serial keyboard/mouse protocol, daisy-chains the mouse and keyboard together.<ref>{{cite web|title=Input Devices|author=Gerhard Lenerz|url=https://www.sgistuff.net/hardware/other/input.html|access-date=2023-12-16}}</ref>