[rescue] WTB: SGI (MIPS architecture) Systems

r.stricklin bear at typewritten.org
Wed May 26 00:25:07 CDT 2010

On May 25, 2010, at 1:50 PM, Richard wrote:

> The first generation stuff came in different models.  The low-end  
> models
> (IRIS 1000) were pure terminals with no local storage or processing.
> The high-end models (IRIS 2000, 3000) had local storage and  
> processing.

mmm... "low-end models" is a misleading description. The IRIS 1000,  
2000, and 3000 series could properly be described as first, second,  
and third-generation, among the m68k models.

The terminals were 1000, 1200, 2000, 2200, 3010, and 3110. The  
workstations were 1400, 1500, 2300, 2400, 2500, 3020, 3030, 3120, and  
3130. Most of the earlier terminals except the 1000 had some local  
storage, though no local OS. The later terminals, such as the 3000- 
series terminals, had local storage and ran a cut-down version of  
their normal GL2 UNIX.

> Wikipedia refers to the IRIS 2000/3000 as the "second product line",
> but I think of all the 68K stuff as first generation.

Wikipedia is technically correct... more-or-less. There is a spectrum  
which makes it difficult to generalize in that way. This is what I've  
pieced together from primary sources and empirical observation.

IRIS 1000/1200 - host-attached terminals; PM1 (8 MHz 68000), Microram  
multibus memory, Excelan EXOS101 ethernet. The processor is very  
clearly a derivation of the Stanford CPU, with some extra EPROMs to  
control the graphics and some circuitry to control the mouse. The  
graphics boards are GF1, UC3, DC3, BP2 and implement GL in hardware -  
what became known as GL1 once GL2 went into development for the IRIS  
2000-series. The 1200 adds ten slots and a removable media bay to the  
1000. The 1200 could have an optional floppy disk drive from which it  
could load applications, or store data.

IRIS 1400/1500 - standalone workstations; PM2 (10 MHz 68010), SGI  
PM2M1 multibus memory, Excelan EXOS101 ethernet. The processor is SGI- 
designed. The 1400 uses ST-506 hard drives on a DSD 5215 (also used in  
the 1200 to control the optional floppy). The 1500 is in a rackmount  
chassis and uses SMD drives on an Interphase 2190 controller. Both use  
the same GL1 graphics hardware as the 1000/1200 terminals; the 1400 &  
1500 UNIX OS adds a "GL1.9" software environment which attempts to  
backport those new GL2 features which were compatible with the GL1  
hardware (most of them).

IRIS 2000/2200 - host-attached terminals; PM2 (10 MHz 68010), SGI  
PM2M1 multibus memory, Excelan EXOS201 ethernet. Same processor as the  
1400/1500, but with new EPROMs to control the new graphics hardware.  
Same chassis differences as with the 1000 & 1200 (I think). The  
graphics boards are GF2, UC4, DC4, and BP3 and implement GL2 in  
hardware. All further m68k IRIS machines use this graphics hardware,  
with varying speeds (and quantities?) of Geometry Engines on the GF2  
board. This first generation has GEs @ 6 MHz. The specification was  
upgraded mid-life to 8 MHz, with no corresponding change in system  
model numbers. New customers just started receiving machines with the  
faster GEs, and old customers were given the opportunity to upgrade  
their GF2 boards.

IRIS 2300/2400/2500 - standalone workstations; PM2 (10 MHz 68010), SGI  
PM2M1 multibus memory, Excelan EXOS201 ethernet. The 2300 and 2400 use  
ST-506 drives on the DSD 5217. The 2500 is rackmounted like the 1500  
and uses the same Interphase 2190 SMD controller.

The PM2 and PM2M1 (and SkyFFP if present) in any 2000-series machine  
can be replaced with IP2 and IM1 (and FP1 if present) to make it the  
"Turbo" version of the same model number. This makes it more-or-less  
the same as an equivalent 3000-series machine, although the  
differences in disk controllers can still throw things off.

IRIS 3010 - standalone terminal - has floppy drive & runs cut down  
version of GL2 unix from local ST-506 disk (20 MB). Still supports old  
host-attachment software interfaces through emulation. Otherwise very  
similar to IRIS 2300T.

IRIS 3020 - standalone workstation - uses ST-506 disk (70 MB),  
effectively identical to IRIS 2400T.

IRIS 3030 - standalone workstation - uses ESDI disk on Interphase  
Storager II controller (170 MB). Otherwise same as IRIS 3020.

At some point the GE speed was bumped again, to 10 MHz. I believe that  
there were GF2s with 12 GEs and GF2s with fewer (8 or 10? - all mine  
have 12) but I wonder if this is the same as with and without Z  

IRIS 3110 - 3010 with 10 MHz GEs and Z clipping.

IRIS 3120 - 3020 with 10 MHz GEs and Z clipping.

IRIS 3130 - 3030 with 10 MHz GEs, Z clipping, 32 bitplanes, 2 IM1s (8  
MB), FP1, and QIC drive.

There was apparently no rackmount chassis for the 3000-series, though  
the GL2-W3.x OS releases still support the Interphase controller for  
the 2500T.

The first-gen "IRIS Superworkstation" which eventually became known as  
the 4D/60 had a MIPS R2300 reference CPU board, replaced early in life  
by the IP4. The earliest 4D1 ("IRIX") releases only support the R2300  
board with Clover1 ("G") graphics, though support for the IP4 had been  
added by release 4D1-2.0 (my earliest release, from August 1987).  
R2300 and Clover1 are still supported in IRIX 4.0.5.

Clover1 graphics (GF3, TB2, DE3, optional ZB2) appears to be an  
architectural extension of the old GL2 boards for the m68k systems,  
rather than anything expressly new, as the Clover2 was.

4D1-3.1 is the first release I have which makes reference at all to  
the IRIX name, which suggests it came on the scene with 4D1-3.0.


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