[bjames]

Hi all,

I am thinking of doing an Indigo2 Extreme project and have a few questions.  The goal is part sentimental as my first sgi for me was a I2 r4400 195mhz zx machine that I purchased directly from SGI Canada as a rectified system (it was really a demo model) back in 1998. That machine is long gone and I thought it would be an interesting addition to my collection.  I want to configure this as a Coff version that can run Alias PA v6 or earlier (old interface) that would have been used in 1993-1995.  So my questions are:

1.  What version of Irix should I install?  5.3, 6.2?
2.  Are Dallas chips easy to source?
3.  What exactly is a COFF operating system?

Thanks

[Raion]

5.3 is the last that supports COFF, and is the last to support R3000 and prior systems

Yes, you can buy NoS or contact Glitch works in Buena Vista, VA. Glitch (Jonathan) is a good dude and has some experience with such stuff.

COFF is an executable format. For UNIX, there's 3 (or if you're a macOS inclusion advocate, 4):

a.out - earliest format still uses in some niche areas. It doesn't support object relocation which makes doing proper shared libs VERY difficult. It was replaced but COFF in System V. Has very limited debug support.

COFF - Common object file format. It's a UNIX and Windows file format (PE is based on COFF) that offers extended debug information, multiple named sections etc. It doesn't support dwarf, a modern debug symbol format, and has limitations on various types of objects and information. It has a limitation in that it cannot be extended to fix the Epoch (Y2038) problem. This is used on 32-bit IRIX and for legacy 5.3 binaries, as 5.3 supports ELF as well.

ELF - executable and linked format. Modern format using DWARF for debug. 6.2+ (o32 ABI and some 64b stuff still uses stabs)

Make sense?

[robespierre]

COFF is a binary executable format that was used by AT&T System V R3 and several commercial Unix vendors. In particular, MIPS and SGI used a variant called ECOFF.
The following version of research Unix, SVR4, changed to a different binary format called ELF.

In the course of IRIX history, SGI's MIPS computers began using ECOFF for executables. Support for ELF binaries began with IRIX 5, but ECOFF continued to be supported. IRIX 6.2 and 6.5 removed ECOFF support.

[weblacky]

To add to Raion, the actual RTC CHIPS are HARD to find now...but gitch works made a "top hat" PCB that replaces the battery and crystal.  You can operate on (de-pott) your RTC to remove the old battery and crystal and install theirs, I've made a thread on this...but the actual chips themselves...have gone VERY hard to find right now...so keep your dead chip and revive it...don't depend on a full replacement.

Depotting an Indigo2 Dallas RTC: https://forums.irixnet.org/thread-2512.html

[gijoe77]

another note - a proper 5.3 COFF system needs to be pre-impact graphics too

[bjames]

Interesting responses.. thanks

Gijoe77, my system is a r4400 GE1 Extreme gfx. I would really like to install PA v6 that uses the old interface with the green buttons along the bottom.

When I had my first Sgi (an indigo2 zx back in 1998) I purchased a used full box set & software for Alias PA/Animator V6 that I was never successful installing as it required an EFS file system. The installer would list all the features and after selecting to install Animator, I would get the error “ no available efs file system is present” or something like that, it was over 20 years ago lol. I do regret parting with the box set as it was pretty impressive, 4 hard & heavy glossy boxes packed with manuals and a poster size tool map.

My hopes is to find the installers for Animator or PA v6 to install onto to I2.

[gijoe77]

PA6 had a grey interface (but still the old style interface), PA5 and earlier have the green interface. I have the CD's for PA4-6, hit me up and I'll get you a copy

[bjames]

Much appreciated. I may take you on that offer.