Jump to content

SGI Indigo²

From RetroTechCollection
SGI Indigo²
SGI Indigo2 teal and IMPACT 10000 (unicron1bot)
A teal Indigo² and three purple Indigo² IMPACT machines on their stands (unicron1bot, CC BY 2.0)
Specifications
ManufacturerSilicon Graphics
TypeWorkstation
Released1993[1]
Discontinued1997; IMPACT models 1998[1]
CPUMIPS R4000, R4400 or R4600 (IP22 board); R8000 (IP26, POWER Indigo²); R10000 (IP28)[2][1]
Memory12 SIMM sockets; 32 to 384 MB on the IP22 board, up to 1 GB on the IP28[3][2]
StorageTwo 3.5-inch bays and one 5.25-inch half-height bay, internal Fast SCSI-2[3]
Display—
Sound—
GraphicsXL, XZ, Elan and Extreme; Solid, High and Maximum IMPACT[2]
ExpansionFour slots on a riser: EISA, of which two can be GIO-64[3]
Power100–120 V or 200–240 V AC, 50/60 Hz[3][4]
Dimensions127 × 470 × 470 mm (5 × 18.5 × 18.5 in)[3]
Weight18 kg (40 lb)[3]
OS / FirmwareIRIX 4.0 to 6.5[1]
PredecessorSGI Indigo[2]
SuccessorSGI Octane[2]
CodenameFullhouse[2][1]

The SGI Indigo² (also written Indigo2), code-named "Fullhouse", is the Silicon Graphics desktop workstation that sat above the Indy in the mid-1990s. It was sold in a teal case and, as the later Indigo² IMPACT, in a purple one, and the Octane replaced it.[2][1] The TechPubs Wiki gives its sales life as 1993 to 1997, with IMPACT production running into 1998; Wikipedia gives 1992 to 1997.[1][2] The Challenge M server is the same machine in a differently coloured and badged case without graphics or audio.[2] The R8000 version is described separately as the SGI Power Indigo². The power supply is the part owners most often have to deal with, followed by the Dallas DS1286 clock chip.[5][6]

Models

[edit | edit source]

The Indigo² was built on three system boards:[2][1]

Indigo² system boards
Board Processor Clock Sold as
IP22 R4000, R4400 or R4600 100 to 250 MHz Teal Indigo², and early IMPACT models
IP26 R8000 75 MHz POWER Indigo² (teal)
IP28 R10000 175 or 195 MHz Indigo² IMPACT 10000 (purple)

[2][1]

The September 1994 product guide lists R4600 (100 MHz), R4400 (200 MHz) and R8000 (75 MHz) processors.[3] IMPACT graphics needs an IMPACT-ready machine: an IMPACT-ready riser card, an IMPACT-ready power supply and a recent enough PROM. A teal Indigo² can be converted with those parts.[2][1] IMPACT graphics is not supported on the R8000 POWER Indigo².[1]

Hardware

[edit | edit source]
SGI Indigo2 power supply cable connectors (Owner's Guide Figure 8-23)
Top view from the rear: power supply at lower left, SIMM sockets in the centre, and the three supply cable connectors (SGI, Owner's Guide Figure 8-23)

System board and CPU module

[edit | edit source]

The CPU module sits on the CPU baseboard, and SGI lists the module and the baseboard as separate replaceable parts. The teal owner's guide gives removal steps for R4000 100 MHz, R4400 150 and 200 MHz and R4600 133 MHz modules, which differ in their fixings.[7] The expansion slots are on a riser board, the EISA backplane, which SGI's IMPACT guide calls the midplane: a gold-coloured metal wall that runs from the front fan along the back of the slots to the rear of the chassis.[8][9]

Memory

[edit | edit source]

There are twelve SIMM sockets in three banks of four, A, B and C, in the centre of the board towards the back. Seen from the back of the chassis, bank C is farthest away and is filled first, and the 5.25-inch drive tray has to come out to reach it.[10] The sockets take 72-pin fast-page-mode SIMMs with parity, 36 bits wide, at 60 or 70 ns; 8M × 72 modules do not work.[1] The IP22 board takes up to 384 MB. SGI set lower limits for the R10000 board than its memory logic allows because of the heat from the DRAMs of the time, and 128 MB SIMMs allow the full 1 GB.[3][2]

Graphics and I/O

[edit | edit source]

The pre-IMPACT boards are the XL24, XZ, Elan and Extreme; the IMPACT boards are the Solid, High, High AA and Maximum IMPACT, which take one, two, two and three GIO-64 positions. All of them use a 13W3 monitor connector.[2] The rear panel has two RS-422 serial ports, a bidirectional parallel port, five audio connectors and Ethernet on AUI or 10BASE-T.[3] Internal drives fit special carriers that plug into a backplane; each carrier has a 50-pin SCSI connector and a standard 4-pin power connector.[2][1]

Power supply and cooling

[edit | edit source]

Two fans cool the Indigo²: one at the front on the left and one inside the power supply at the back.[11] The supply connects to the CPU baseboard by two cables beside the memory banks and to the drives by a third.[12] IMPACT boards draw more than the GIO-64 bus can deliver, so an IMPACT supply also feeds the midplane through a ribbon cable and a twisted-pair cable.[2][13] SGI's guide warns that early supplies may not be adequate for newer configurations.[11]

Supply part numbers reported by owners include 060-0027-001 (385 W, in a 1996 teal IP22 machine), 060-8001-001 (385 W) and 060-0027-002 Rev A (in an R10000 Solid IMPACT). IMPACT supplies were made in 36 A and 48 A versions; owners use the 48 A version for several graphics boards or Maximum IMPACT.[14][15][5] The IMPACT supply is built as a high-voltage board and a low-voltage board joined by heavy soldered flat conductors; one later revision uses connectors between the boards instead.[16][17]

Clock and NVRAM

[edit | edit source]

The clock is a Dallas DS1286 timekeeper with its battery sealed inside. The chip is no longer made, and owners either fit a used one or cut into the package to wire in a replaceable cell.[6][18] An Indigo² still boots with a flat clock battery, though IRIX may complain about the date.[15]

Known faults

[edit | edit source]
  • Power supply failure. Owners report supplies that trip out after 30 to 60 minutes, supplies that let the fans twitch and nothing more, and an IMPACT supply that chimed, clicked and restarted in a loop. Repairs have often failed: one owner recapped an Indigo² supply and replaced MOSFETs without success, and a repair firm recapped another, made two further attempts and then refunded the owner.[5][15][17] See SGI Indigo² Capacitor Replacement Guide.
  • Shutdown in a hot room. One Indigo² switched off whenever the room passed about 80 °F (27 °C) and would only restart after cooling and unplugging, which forum members attribute to a thermal cut-out.[19]
  • A backplane or CPU module loosened in storage. Machines that would not start after years in store came back once the midplane and CPU module were pressed firmly home.[15][9]
  • Flat DS1286 battery.[6]
  • A forgotten PROM password, cleared with the jumper at the front edge of the CPU baseboard.[20]

See SGI Indigo² Troubleshooting Guide and SGI Indigo² General Maintenance.

Documentation

[edit | edit source]

Contents and coverage are on SGI Indigo² Documentation.

[edit | edit source]
  • Front of a teal Indigo² (Rules666, CC BY-SA 4.0)
    Front of a teal Indigo² (Rules666, CC BY-SA 4.0)
  • Indigo² High IMPACT at the Vintage Computing Festival Berlin 2014 (Morn, CC BY-SA 3.0)
    Indigo² High IMPACT at the Vintage Computing Festival Berlin 2014 (Morn, CC BY-SA 3.0)
[edit | edit source]

References

[edit | edit source]
  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 "Indigo 2", TechPubs Wiki, tech-pubs.net (retrieved 21 October 2026). Production dates, IP22/IP26/IP28 boards, SIMM type, IMPACT-ready requirements, IRIX versions.
  2. ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 "SGI Indigo2", Wikipedia, revision of 22 June 2026, en.wikipedia.org/wiki/SGI_Indigo2. Code name, models, system boards and CPUs, memory limits, graphics options, IMPACT power arrangement, drive carriers, Challenge M, predecessor and successor.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 Silicon Graphics, Indigo2 Product Guide, INDIGO2-TM-GD (09/94), 1994, pp. 2 and 8 (File:SGI Indigo2 Product Guide (INDIGO2-TM-GD-09-94).pdf). Twelve SIMM sockets, memory 32–384 MB, CPUs, drive bays, I/O, slots, dimensions, weight 40 lb, power requirements.
  4. ↑ Silicon Graphics, Indigo2 IMPACT Workstation Owner's Guide, 007-2849-004, 1996, p. 299, Table 10-1 (File:SGI Indigo2 IMPACT Workstation Owner's Guide (007-2849-004).pdf). 100–120/200–240 V AC, 50/60 Hz, 8/4 A.
  5. ↑ 5.0 5.1 5.2 "Indigo2 PSU woes and questions", IRIX Network forums, 23 July 2022, forums.irixnet.org. Supply 060-0027-002, 36 A and 48 A IMPACT supplies, supplies tripping after 30–60 minutes, failed repairs.
  6. ↑ 6.0 6.1 6.2 "DIY Drilling Indigo2 RTC DS1286 Chip - Photos and Final Results", IRIX Network forums, weblacky, 17–22 July 2019, forums.irixnet.org. DS1286 in the Indigo², no longer produced, adding a replaceable cell.
  7. ↑ SGI, 007-9096-050, pp. 169–175 and 185–199. CPU module types and the CPU baseboard as replaceable parts.
  8. ↑ SGI, 007-9096-050, p. 127. The EISA backplane described.
  9. ↑ 9.0 9.1 SGI, 007-2849-004, p. 227. Pressing the EISA midplane firmly home when there is no LED.
  10. ↑ Silicon Graphics, Indigo2 Workstation Owner's Guide, 007-9096-050, 1996, pp. 51–53 (File:SGI Indigo2 Workstation Owner's Guide (007-9096-050).pdf). Twelve SIMM sockets in banks A, B and C.
  11. ↑ 11.0 11.1 SGI, 007-9096-050, p. 128. The two fans; early power supplies may not be adequate for newer configurations.
  12. ↑ SGI, 007-9096-050, pp. 176–183. Power supply cables and removal.
  13. ↑ SGI, 007-2849-004, pp. 272–281. IMPACT power supply, midplane ribbon and twisted-pair power cables.
  14. ↑ "Repair Request: Indigo2 powersupply", IRIX Network forums, 12 July 2026, forums.irixnet.org. 385 W supply 060-0027-001 in a 1996 teal IP22 Indigo².
  15. ↑ 15.0 15.1 15.2 15.3 "Indigo2 power on issue", IRIX Network forums, February to August 2019, forums.irixnet.org. Booting with a dead NVRAM, supply 060-8001-001, reseating the midplane and CPU after storage.
  16. ↑ "Two Indigo2 PSUs. Combine half of one with the other?", IRIX Network forums, weblacky, 13 November 2021, forums.irixnet.org. High- and low-voltage halves of the IMPACT supply and their soldered conductors.
  17. ↑ 17.0 17.1 "Indigo 2 Impact Power Supply Boot Loop", IRIX Network forums, December 2024 to July 2025, forums.irixnet.org. Boot loop traced to the supply; later revision with connectors between boards.
  18. ↑ "Dallas DS1286 RTC, many on ebay?", IRIX Network forums, 14 October 2020, forums.irixnet.org. Sourcing used DS1286 chips.
  19. ↑ "Indigo 2 powers down at high room temp.", IRIX Network forums, 9 April 2022, forums.irixnet.org. Shutdown above about 80 °F and a likely thermal cut-out.
  20. ↑ SGI, 007-9096-050, pp. 150–151. Password jumper on the CPU baseboard.


Retrieved from "https://retrotechwiki.com/index.php?title=SGI_Indigo²&oldid=29343"