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SGI Indy

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SGI Indy

This will be a collection of information regarding the SGI (Silicon Graphics) Indy workstation. The Indy was released in 1993 and discontinued in 1997.

SGI Indy Workstation

Introduced in 1993, the Indy was the fruit of Silicon Graphics effort to muscle into the market for desktop publishing, low-end CAD, and multimedia. At the time, the market was mostly dominated by Apple Computer. The Indy was the first computer to include a digital video camera, and was built with a (then) forward-looking architecture including an on-board ISDN adapter. With the inclusion of analog and digital I/O, SCSI, and standard composite and S-Video inputs, the Indy really was a multimedia machine.

The Indy was superseded by the SGI O2 in 1996.

Physical Characteristics

Indy with cover removed

The Indy packed a large number of features into a compact (41 cm × 36 cm × 8 cm), simple, and elegant package. Standard features included an IndyCam webcam, 10MB/s Fast SCSI, 10Mb/s ethernet, ISDN, PS/2 keyboard and mouse ports, two serial ports, a parallel port, onboard audio, and VINO video inputs (see below). One unusual option for the Indy was an Insite floptical drive. The floptical used 21 MB optical diskettes, but could read and write standard 3.5" magnetic floppies as well.

The sturdy, pastel-colored "pizza box" chassis is comparable to Sun's SPARCstation systems of the same era, and is designed to fit underneath a large CRT monitor. It can accommodate two internal 3.5" SCSI drives and two levels of expansion cards. With all cooling accomplished via a single fan at the rear of the power supply, the Indy is a relatively quiet system, and it has modest power requirements.

The Indy chassis was also used in the Silicon Graphics Challenge S, an entry-level server system.

CPU Options

180MHz R5000 CPU
SGI Part Number Description
030-8100-002 R4000PC 100MHz Primary Cache only
030-8101-004 R4000SC 100MHz 1MB SC
030-8260-002 R4400SC 100MHz 1MB SC
030-8201-001 R4400SC 150MHz 1MB SC
030-8205-003 R4400SC 175MHz 1MB SC
030-0882-001 R4400SC 200MHz 1MB SC
030-8236-001 R4600PC 100MHz Primary Cache only
030-8252-004 R4600SC 133MHz 512KB SC
030-0986-002 R5000SC 150MHz 512KB SC
030-0991-002 R5000PC 150MHz Primary Cache only
030-0985-002 R5000SC 180MHz 512KB SC

Indy's motherboard has a socket for the Processor Module (PM). Early Indys used the 100 MHz MIPS R4000 CPU, which quickly proved inadequate. The Indy, at the bottom of SGI's price list, thus became the primary platform for MIPS's low-cost, low-power-consumption R4600 CPU series. The R4600 had impressive integer performance, but had poor floating-point capability. This, however, wasn't too huge of a problem in a box that was generally not designed for floating-point-intensive applications. For this reason, the R4600 made an appearance outside the Indy line just once, and only briefly, in the SGI Indigo2. This series of CPU issues, along with the relatively low-powered graphics boards, lower maximum RAM amount, and relative lack of internal expansion ability compared to the SGI Indigo led to the Indy being pejoratively described amongst industry insiders as "An Indigo without the 'go'."

The R4600 chip itself has no L2 cache controller, external controller was used to add 512K of L2 cache. R4600s processor modules both with an L2 cache (SC) and without (PC) are common in the Indy. At the same clock rate, the SC version of the processor module is generally 20 to 40 percent faster than the PC version, due to the memory cache.

The Indy was also the first SGI to utilize the MIPS R5000 CPU, which offered significant advantages over the R4400 and R4600 it replaced. The Indy's 180 MHz R5000 module can be overclocked to 200 MHz by replacing its crystal oscillator chip (50.000000 MHz CXO7050T3/HCMOS/050/20/70 3.3V SMD). See SGI Indy R5000 200MHz Overclock for more information.


At the beginning of its life, the Indy shipped with only 16MB of RAM. IRIX 5.1, the first Operating System for the Indy, did not take full advantage of the hardware due to inadequate memory management. SGI realized this and quickly increased the base specification to 32 MB, at considerable cost. Subsequent IRIX releases made huge improvements in memory usage. The latest release of IRIX available for the Indy workstations is 6.5.22.

The Indy features eight 72-pin RAM slots (two banks, each with four slots) for a maximum memory configuration of 256MB. Compatible RAM must be 36-bit wide 72-pin SIMMs (FPM, parity, 70 or 60ns). The Indy board uses gold on the memory slots and you should use SIMMs with gold leads if possible, though many people have reported standard tin leads working fine. You may need to re-seat the SIMMs after a certain number of years.


24- and 8- bit XL Graphics Boards

Three graphics subsystems were available for the Indy: 8-bit XL, 24-bit XL, and 24-bit XZ. Each supported a resolution of 1280 × 1024 at a refresh rate of 76 Hz, and had a Sun Microsystems-style 13W3 monitor connection. All of these graphics options use a 32-bit GIO32 bus to interface with the system.

The first two boards are referred to by the code names "Newport", "NG1", or "XL", depending on which version of the marketing or reference material you read. They are comprised of a single GIO32 board, and are essentially the same except for the number of RAM chips soldered to the board.[1]

NG1 is probably an acronym for Newport Graphics 1. XL is also used to refer to similar graphics subsystems in other SGI workstations (notably the Indigo2), with the implication that their performance characteristics should be similar.

One exception to this naming scheme came with the introduction of the R5000 microprocessor. An R5000 CPU can perform 3D geometry calculations faster than the XZ subsystems's two Geometry Engines--as a result, all 3D is done in software. XZ graphics were rarely paired with the R5000 for this reason. To emphasize the enhanced performance provided by the R5000's new instruction set, the product was referred to as "XGE" instead, although the hardware was identical.[2] The label "XGE" was simply another example of the disconnect between marketing material and actual engineering design. "XGE24" was another name for 24-bit XL graphics on an R5000 system.[3]

A rare option associated with the Newport graphics line was the ability to add a second graphics card (resulting in a dual-head configuration) to the Indy. Functionally, the dual-head boards were the same as two normal XL 8- or 24-bit boards, but the set of two boards were specialized such that the GIO32 connectors were located in physically different places from normal Newport boards.[4] The board mounted closest to the motherboard is different, while the top/second board is a normal Newport board.

The third type of graphics board was the "XZ", explained below.

8-bit XL

Also known as Newport graphics, these were designed for general 2D X11 applications; no hardware 3D acceleration was included. These worked best for 2D CAD or general office use.

24-bit XL

Using an identical circuit board as the 8-bit XL, the 24-bit XL included three times as much framebuffer memory to accommodate 24-bit color. A popular choice for some general graphics work, since its 2D performance is better than the XZ card.


XZ Graphics for Indy

These graphics were a port of the Indigo²'s XZ (Elan) graphics into Indy - they offered very good non-textured 3D performance at the time, sacrificing a bit of 2D performance in return. The XZ graphics option was not widely used in Indy systems that used the R5000 CPU. This was mostly due to extensions of the MIPS instruction set that were implemented in the R5000. With the new instructions, the R5000 CPU could perform coordinate transformations faster than the XZ graphics board. Because XZ graphics only provided assistance to the main CPU for coordinate transformations, 3D rendering was often faster when implemented only in software. However, using XZ to perform coordinate transforms does free the CPU to perform other rendering-related calculations. These graphics take the form of two boards, one on top of the other, and occupy one GIO slot. It is not possible to install any other GIO option boards while the XZ boards are installed.


Indy Video option board

The Indy was the first SGI to have video inputs by default. Every Indy has a composite, S-Video, and digital video input built into the motherboard, which are collectively known as "Vino" (video input, no output) video. None of them are of professional quality, but are still usable. The digital input is a proprietary D-sub connector with a rectangular array of pins, and is used by the SGI IndyCam. The connector is the same as serial ports on Cisco routers, however is electrically different.

The maximum supported input resolution is 640x480 (NTSC) or 768x576 (PA]). It takes a fast machine to capture at either of these resolutions, though; an Indy with slower R4600PC CPU, for example, may require the input resolution to be reduced before storage or processing. However, the Vino hardware is capable of DMAing video fields directly into the framebuffer with minimal CPU overhead.

None of the Indys support video output by default - that would require the Indy Video GIO32 card. In addition, there is an optional video module called CosmoCompress, which offers realtime JPEG video compression and decompression and uses up another GIO32 slot.

Compression Board

Indy Compression 2

We believe there are two different image compression boards available for the Indy including the Cosmo Compress and the Indy Compression 2. As noted above, the Cosmo Compress board offers real-time JPEG video compression and decompression.


The Indy has two drive bays for 1-inch tall 3.5" drives. The upper drive bay is externally accessible and may hold a SCSI floptical drive. All external and internal drives share a single Fast SCSI bus (unless a GIO32 SCSI card has been installed).

Hard Disks and heat/power concerns

A post by Dave Olson in comp.sys.sgi.hardware notes that the Indy cannot sustain the heat output of a 7200RPM or higher SCSI drive internally. If you intend on using modern SCSI hard disks (likely 7200RPM or higher) in your Indy, you must have some sort of additional cooling. The power draw may also be too much for the old power supply. You may want to put the drive into an external enclosure instead, or just use a SCSI2SD as discussed further below.


External CD-ROM drive connect via SCSI connector at rear side of the box. Typical drive supports boot, OS install, audio. Special ROM is required to boot from for certain device types. [5] A small number of CD-ROM drives have the firmware needed to do audio over SCSI.


All Indys shipped with Attachment Unit Interface (AUI)/10BASE-T Ethernet and ISDN as standard equipment. The Ethernet ports are half-duplex only. The 10BaseT port takes precedence over the AUI port - if the system detects a carrier on both ports, it will use the 10Base-T.

Two different manufacturers produced 100BASE-TX Ethernet cards compatible with the Indy, both of which attached to the system using the GIO32 bus. Set Engineering produced one such fast ethernet card, based on the Texas Instruments ThunderLAN chipset, under contract with SGI. In addition, Phobos also produced two models of fast ethernet cards for the Indy (the G100 and G130).

The ISDN port provided on the Indy has no NT1. An external NT1 is required to use the ISDN port in North America.

Power Supply and Cooling

Main article: Indy Power Supplies

Sony PSU With Top Cover Removed

Indys shipped with two different power supply variants, both rated at approximately 170W. Early Indys received a Nidec power supply, while later machines were outfitted with a Sony model with similar output specifications. The Nidec models have long been considered the less reliable PSU variant, although as of 2019 Sony PSU failures appeared to becoming more common. All Indy power supplies also contain the system's internal speaker as well as power and reset switches connected to a small logic board.

Both power supplies included the Indy's sole cooling fan, a 92mm exhaust fan. The fan, which operates at variable speed, is mounted at an angle and pulls air through the machine and power supply before blowing it out the rear of the unit. At least for Sony PSUs the fan was a Panaflo FBA09A12H 12-volt fan. In the Nidec variant, the fan is always on although its speed increases when the computer becomes hot. The fan in the Sony, however, comes to a complete stop at low system temperatures. This might contribute to failures of the Sony PSU when the machine is operated without the cover, thereby allowing the CPU and other components to shed heat through convective cooling, which can keep the PSU fan from operating at all, while temps inside the closed PSU increase.

Modern Indy Usage

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The SGI Indy can only be upgraded to a certain point, and OS wise you can go as far as IRIX 6.5.22. We'll discuss a few things we've come across while working on our own Indy as part of the Higher Intellect Technology Museum. If you're interested in running some more recent open source software made available by SGI enthusiasts, you'll want to consider the R5000 MIPS4 generation CPU. The Nekoware community project features a number of software packages which require a MIPS4.

The component of the Indy most prone to failure is the Nidec/Power General power supply. New power supplies are manufactured by Sony and sold through resellers, however they are expensive.

The Indy's Ethernet address, which doubles as the system's serial number, is stored in battery-backed RAM. This means that when the internal battery dies, so does the system - it will hang at the PROM monitor and refuse to boot any further as a result of the Ethernet address being all FFs. A non-amateur user can replace the PROM battery and reprogramme it. The original battery was made by Dallas Semiconductor, now owned by MAXIM. The original unit was marked the "DS-1386-8K-150", however its replacement unit, the "DS-1386-8K-120" can be directly substituted with no ill effects.

One can set a new MAC address from the Command Monitor with the command "setenv -f eaddr xx:xx:xx:xx:xx:xx". The -f switch here will force the new MAC address. The MAC address is (usually) on a sticker to the rear of the unit, and hence can be reprogrammed without losing software licences, which often rely on it to verify ownership. Otherwise, any MAC address in SGI's block is usable.

See also this note in the IRIX for Indy and Challenge S page

IRIX for Indy and Challenge S#Corrupt MAC addresses

Also reference Replacing and reprogramming Indy Dallas chip for information about resolving problems caused by bad NVRAM.

Upgrading Hardware

To achieve the highest possible performance, you'll want to install an R5000SC CPU module. In order to use any R5000 CPU in the SGI Indy you'll need to ensure the PROM version output matches "PROM Monitor SGI Version 5.3 Rev B10 R4X00/R5000 IP24 Feb12, 1996 (BE)" which can be done by entering the console from the initial Indy boot options and running the "version" command. If your Indy is running an older PROM, you can still find later versions on the used market. If you're performing the R5000 upgrade in an Indy with an existing IRIX install, you will need to perform a re-install as the OS requires a different set of libraries for this CPU (MIPS4 generation as opposed to the R4X00 MIPS3 CPU more commonly found in the Indy).

As the prices for 72-pin RAM on the used market are fairly low, you'll want to upgrade the Indy to at least 128MB or right to the maximum of 256MB especially if you're going to run IRIX 6.5.22. If your Indy is still running the 8-bit XL graphics, you'll likely want to upgrade to the 24-bit graphics card. The XZ board provides more powerful 3D abilities for Indys running R4X00 CPUs, but if you're running the R5000 you'll probably want the XL board as the CPU is capable of doing the 3D processing. For local disk storage in your Indy, please see the SCSI2SD section below as it may not be worth attempting to find old SCSI drives to use.

Running IRIX 6.5.22

If you've upgraded the CPU and RAM in your Indy and now want to run the latest available IRIX version, you'll need the core IRIX 6.5 CDs along with the 6.5.22 overlays and application CDs. Now, most likely your Indy is only entitled to use a version of IRIX such as 5.3 or 6.2 meaning you would normally need to purchase IRIX 6.5 and the 6.5.22 upgrade. As IRIX is no longer a supported operating system and you may find it difficult to find copies of the software on the used market, you do have the option of downloading these images from sites such as WinWorld. This probably isn't something a true SGI enthusiast would enjoy you doing but IRIX support ended in 2013 and we would consider this to essentially be a dead operating system at this point.

Now that you're purchased or downloaded the required media, what now? The SGI Indy does not come with an internal CD-ROM drive so your best bet is using an external CD-ROM. We've read that the Indy should work fine with most SCSI CD-ROMs, and we performed the 6.5.22 install ourselves using an Apple 4x (CD 600e) external drive and HPBD50 to CN50 cable. When you boot the Indy, enter the console from the maintenance menu and check that your drive shows up by running "hinv -v" and finding the listed device. If you see the CD-ROM drive show up as every SCSI ID on the bus, that means you've got an ID conflict and you need to change the jumper.


Due to the age of the hardware, likely any original SCSI disks in the Indy computers are either dead or nearing death. There are a few solutions for replacing the internal storage with something more reliable, but we'll focus on the SCSI2SD option here. This information is originally found at SCSI2SD among other places.

  1. Purchase a SCSI2SD v5/v6 board (v6 is faster) and ideally a class 10 microSD card. The SCSI2SD can be ordered from
  2. Download the scsi2sd-util application from and plug the USB port in
  3. Under the General Settings tab, enable the options "Enable Parity" and "Enable SCSI2 Mode"
  4. Under the Deivce 1 tab, set the ID to something other than 0 (generally you should use 1). Type is hard drive, SD card start sector is 0, sector size is 512. The sector count and other options should have populated themselves and can be left. If the sector count is empty you might need to "load from device" though this will require you to set all the options again. When done, save to device.
  5. Remove the onboard termination resistors from the SCSI2SD socket as this is not needed in the Indy.
  6. You might need to get creative with mounting the SCSI2SD inside the Indy...

Assuming you don't have any other OS drive in the system, open a console when the Indy boots into its system menu and run a "hinv" to verify the SCSI disk shows up (should be bus 0, ID 1).


Non-parity memory modules

The Indy requires specific types of RAM sticks so if an invalid type of module is installed, the console may output errors such as:

Exception: <vector=Normal>
status register: 0x30004803<CU1,CU0,IM7,IM4,IPL=???,MODE=KERNEL,EXL,IE>
Cause register: 0xc000<CE=0,IP8,IP7,EXC=INT>
Exception PC:0xbfc03264, Exception RA: 0xbfc0325c
Interrupt exception
Bus Error ?

You need to use FPM memory modules with parity.

Capacitor replacement (power supply unit)

The aluminum capacitors in the power supplies should likely be replaced at this point due to age. See below for a list of capacitors found inside the PSU.

NIDEC/Power General

  • 2 x 680uf 200v
  • 1 x 1uf 400v
  • 1 x 100uf 35v
  • 2 x 39uf 35v
  • 5 x 220uf 35v
  • 2 x 6800uf 10v
  • 1 x 1000uf 10v
  • 1 x 4700uf 6.3v



Indy Gallery

Related Links

See also