The Indigo, introduced as the IRIS Indigo, is a line of

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 ...

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

s developed and manufactured by

Silicon Graphics, Inc. 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 ...

(SGI). SGI first announced the system in July 1991. The Indigo is one of the most capable graphics workstations of its era, and was essentially peerless in the realm of hardware-accelerated three-dimensional graphics rendering. For use as a graphics workstation, the Indigo was equipped with a two-dimensional

framebuffer A framebuffer (frame buffer, or sometimes framestore) is a portion of random-access memory (RAM) containing a bitmap that drives a video display. It is a memory buffer containing data representing all the pixels in a complete video frame. Mode ...

or, for use as a 3D graphics workstation, with the Elan graphics subsystem including one to four

Geometry Engine Geometric manipulation of modelling primitives, such as that performed by a geometry pipeline, is the first stage in computer graphics systems which perform image generation based on geometric models. While geometry pipelines were originally implem ...

s (GEs). SGI sold a server version with no video adapter. The Indigo's design is based on a simple cube motif in

indigo InterGlobe Aviation Limited (d/b/a IndiGo), is an India, Indian airline headquartered in Gurgaon, Haryana, India. It is the largest List of airlines of India, airline in India by passengers carried and fleet size, with a 64.1% domestic market ...

hue. Graphics and other peripheral expansions are accomplished via the

GIO Gio or GIO may refer to: Science and technology * Gi/o, protein subunits * GIO, a computer bus * GIO (software), a library for accessing virtual file-systems * 11084 Giò, a main belt asteroid * Gibioctet, a unit of digital information * ...

32 expansion bus. The Indigo was superseded generally by the

SGI Indigo2 SGI may refer to: Companies * Saskatchewan Government Insurance * Scientific Games International, a gambling company *Silicon Graphics Silicon Graphics, Inc. (stylized as SiliconGraphics before 1999, later rebranded SGI, historically known a ...

, and in the low-cost market segment by the

SGI Indy The Indy, code-named "Guinness", is a low-end multimedia workstation introduced on July 12, 1993 by Silicon Graphics Incorporated (SGI). SGI developed, manufactured, and marketed Indy as the lowest end of its product line, for computer-aided des ...

Technical specifications

The first Indigo model (code-named ''Hollywood'') was introduced on July 22, 1991. It is based on the IP12 processor board, which contains a 32-bit MIPS

R3000A The R3000 is a 32-bit RISC microprocessor chipset developed by MIPS Computer Systems that implemented the MIPS I instruction set architecture (ISA). Introduced in June 1988, it was the second MIPS implementation, succeeding the R2000 as the flags ...

microprocessor soldered on the board and proprietary memory slots supporting up to 96 MB of RAM. The later version (code-named ''Blackjack'') is based on the IP20 processor board, which has a removable processor module (PM1 or PM2) containing a 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 imp ...

(100 MHz) or

R4400 The R4000 is a microprocessor developed by MIPS Technologies, 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 f ...

processor (100 MHz or 150 MHz) that implements the MIPS-III instruction set. The IP20 uses standard 72-pin SIMMs with parity, and has 12 SIMM slots for a total of 384 MB of RAM at maximum. A

Motorola 56000 The Motorola DSP56000 (also known as 56K) is a family of digital signal processor (DSP) chips produced by Motorola Semiconductor (later Freescale Semiconductor and then NXP) starting in 1986 with later models still being produced in the 2020s. ...

DSP is used for Audio IO, giving it 4-channel 16-bit audio.

Ethernet Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...

is supported on board by the SEEQ 80C03 chipset coupled with the HPC (High-performance Peripheral Controller), which provides the

DMA DMA may refer to: Arts * ''DMA'' (magazine), a defunct dance music magazine * Dallas Museum of Art, in Texas, US * BT Digital Music Awards, an annual event in the UK * Danish Music Awards * Detroit Music Awards * Doctor of musical arts, a degree ...

engine. The HPC interfaces primarily between the

bus and the Ethernet,

SCSI Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices, best known for its use with storage devices such as hard disk drives. SCSI was introduced ...

(WD33C93 chipset) and the 56000 DSP. The GIO bus interface is implemented by the PIC (Processor Interface Controller) on IP12 and MC (Memory Controller) on IP20. Much of the hardware design can be traced back to the

SGI IRIS 4D The SGI IRIS series of terminals and workstations from Silicon Graphics 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 N ...

/3x series, which shared the same

memory controller A memory controller, also known as memory chip controller (MCC) or a memory controller unit (MCU), is a digital circuit that manages the flow of data going to and from a computer's main memory. When a memory controller is integrated into anothe ...

, and optionally DSP as the IP12 Indigo. The 4D/30, 4D/35 and Indigo R3000 are all considered IP12 machines and run the same IRIX kernel. The Indigo R3000 is effectively a reduced cost 4D/35 without a VME bus. The PIC supports a VME expansion bus (used on the 4D/3x series) and GIO expansion slots (used on the Indigo). In all IP12, IP20, and IP22/IP24 (see

) systems the HPC attached to the GIO bus.

Graphics options

Entry graphics

For entry graphics, the 8-bit color frame buffer comes in three versions. One version uses the system's GIO expansion bus. Another uses the main backplane like the XS, XZ, and Elan graphics options. The final is the same, but adds a second video output, giving the computer the ability to have two "heads", or monitors.

XS Graphics

The Indigo's XS Graphics option has a single GE7 Geometry Engine (GE), a RE3 Raster engine, a HQ2 Command engine, VC1, XMAP5. It is ideal for low-cost wireframe operations, compared to more powerful, and expensive options for textured graphics. Part of SGI's Express line of graphics, four XS graphics options were produced for the Indigo: the XS-8 offers 8-bit color, with one VM2 video RAM module; the XS-Z adds the ZB-4 Z buffer; the XS-24 adds two VM2 modules and offers 24 color bits and 32 bits including brightness; and the XS-24Z adds a Z buffer.

XZ Graphics

The XZ graphics option is also a member of SGI's Express graphics line. It is similar to the XS-24z, but it includes a second GE7 Geometry Engine ASIC, doubling its geometry performance.

Elan Graphics

The highest performance graphics option offered for the Indigo, it is a member of SGI's Express graphics line. It is like the XS-24z and XZ, but has 4 GE7 Geometry Engine ASICs, giving it twice the performance of the XZ option.

Operating system

The Indigo was designed to run

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 ...

, SGI's version of

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 ...

. The Indigos with R3000 processors are supported up to IRIX version 5.3, and Indigo equipped with an R4000 or R4400 processor can run up to IRIX 6.5.22. Additionally, the free

Unix-like A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...

operating system

NetBSD NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to ...

has support for both the IP12 and IP20 Indigos as part of the sgimips port.

SGI timeline

Popular culture

The Indigo was featured in ''

Jurassic Park ''Jurassic Park'', later referred to as ''Jurassic World'', is an American science fiction media franchise created by Michael Crichton, centered on a disastrous attempt to create a theme park of De-extinction#Cloning, cloned dinosaurs. It bega ...

'' as the rendering system for Samuel L. Jackson's character Arnold and his station to render graphics for Park Control Systems. It was paired to a

Macintosh Quadra 700 The Macintosh Quadra 700 is a personal computer designed, manufactured and sold by Apple Computer from October 1991 to March 1993. It was introduced alongside the Quadra 900 as the first computers in the Quadra series, using the Motorola 6804 ...

References

External links

IP12 - LinuxMIPS

Technolust: The Indigo Page (Silicon Graphics - SGI)

SGI Indigo / Silicon Graphics R4000 Architecture

Indigo Power Supply basics
{{Authority control

Indigo InterGlobe Aviation Limited (d/b/a IndiGo), is an India, Indian airline headquartered in Gurgaon, Haryana, India. It is the largest List of airlines of India, airline in India by passengers carried and fleet size, with a 64.1% domestic market ...

32-bit computers 64-bit computers