[GRudolf94]

Hello again, everyone. I've revised part of my stuff and the one of the ugliest Indigo² to survive is sort of alive again.
Will still not complete the selftest, I suspect it is missing one or two voltage rails I haven't figured out the pinout for just yet. It does successfully complain about missing RAM on the serial console, or a bad RTC/datapath test fail if I pull the NVRAM (that is, if failing can be considered a success). Well, any result is better than no result.

As soon as the thing is done, I'll release an adapter, or at least the documentation to make your own. Also important, Indigo2 IMPACT people will want their MARDIGRAS cards to work, so I'll have to figure out something that will supply the over-30A current on a 3.3V rail using a regular ATX PSU, and find out the type of connector and cable used for the IMPACT rail (it's made by AMP, but I couldn't find a series). Running a base XZ system already is pretty demanding for new ATX units, so I'll probably end up making a full docset with recommendations and perhaps a list of suitable models. Note from the cable clutter hehind the HDD cage that a modular unit would've been the ideal

Please excuse the beaten-up case, no front door, mismatching skins, and no drive sleds, this was a junkyard rescue by a good friend that gave it to me.

I'll let the pics speak for themselves for now

The overall innards:


Close-up of how the PSU sits directly above the wires, invading the motherboard's space a bit. It is sitting atop the gutted shell of an OEM ZyTec PSU:


Fugly AC cable routing:


It does close and power on!

[Trippynet]

Nice work!

[gijoe77]

This is fantastic! Very awesome

[sgi_tx]

This is a really exciting and promising effort. Is anyone aware of updates since the original post?

[Raion]

He's not been around for a year so who knows?

[sgi_tx]

I see.

There are some ATX supplies with 30A on the 3.3V rail and 35+A on the 5V rail. For example:

https://www.newegg.com/logisys-computer-...6817170019

I wonder if anyone else here has tried an ATX supply with an Indigo2?

[GRudolf94]

Am back. Sorry for disappearing everyone, but life's been chaos and I haven't had time to work on my neglected I2, nor my functional Octane, even.

sgi_tx has already talked to me in private, and as functional PSUs dwindle in number, we have to find a reliable repair source, develop technique and write a manual, and a viable replacement for units deemed unfixable. I see someone else on the forum has also achieved success converting their machine - I have half of a solution to drive the IMPACT rail from a PCIe 6pin plug, but of course, we would still need the actual cabling from an original PSU if we don't wanna touch the riser.

I really want to get this done, but it relies on me finding time, money for components (especially living in South America), and space to work on the I2. For IMPACT testing, I ideally also first have to fix my SI board, which has parts missing.

[Raion]

I think that it's possibly at most viable for a normal I2, at most. The amount of current the IMPACT connector takes I think will probably cause a fire if you pull it off a standard ATX wiring harness with the appropriate DC-DC converter.

[GRudolf94]

"... The amount of current the IMPACT connector takes I think will probably cause a fire if you pull it off a standard ATX wiring harness with the appropriate DC-DC converter."

If you stop and think about it, the worst case is 46A*3.5V (or 3.3V, SGI couldn't make their minds up). That gives us ~160W. I bet I could mock up a stupid prototype by bastardizing an old GPU and reusing its onboard DC-DC.

Anyway, it's not rocket surgery, and I am really eager to implement a proper conversion. Still looking for a proper IMPACT connector so that no original PSUs would have to be molested for that. Messaged TE Electronics' sales dept and they couldn't find me a match from the old AMP line.