Just picked up a couple SGIs - any new-owner advice?

[JeffC]

Recently I ran across a couple SGI machines for sale, and despite the fact I really don't need them, and don't have a compatible monitor, I went ahead and bought them. I always marveled at SGIs as a kid in the early 90s, but of course saying they were cost-prohibitive is an understatement. 20+ years ago I had a couple and tinkered with them briefly, but did not own them long before I sold them.

One of the new machines is an Indigo with I believe a R4400 and XS24 graphics. The PRAM battery is dead so we were stuck at the low battery warning and could not check hinv to confirm the processor, but I did pull the graphics board and confirm it is XS24. The other is an Indigo2 with a 175mhz R10000 and Solid Impact graphics. I also got a Indigo-compatible granite serial keyboard and beige mouse, and matching purple stands for the Indigo2.

Other than replacing the Indigo PRAM battery, are there any maintenance tasks that need to be done to these machines? They sat for the last 20 years or so. I have heard the PSUs generally need to be recapped, are there any other caps that are prone to leakage?

 

[ClassicHasClass]

I'm not very familiar with the original Indigo, but I just restored an Indigo2 very similar to yours: https://oldvcr.blogspot.com/2025/09/refurb-weekend-silicon-graphics-indigo.html

The Indigo2 is pretty tough. The power supplies do die, but recapping them needs to be done on the high-voltage side, so it's not a novice task. Unfortunately no one has come up with an ATX conversion kit for these like there is for the Fuel. I also replaced the DS1286 in it, but this isn't as critical as doing so is with, say, the Indy.

Good call on the stands - you shouldn't run the Indigo2 on its side without them. I'm also assuming you have a display which can handle SGI 13W3 and sync-on-green.

 

[JeffC]

Wow that's a great blog post, I just gave it a quick skim, I'm looking forward to sitting down and reading through it. You weren't kidding about "just restored", the post is only two days old.

I'll look into recapping the PSU, looking at the link in your blog post it doesn't look terribly difficult. Hopefully I can find a capacitor list, otherwise I'll have to take the PSU apart and put together a list.

I don't have a display yet, I am familiar with the SOG requirement. I need to see what I can find, due to space limitations I want to find a flat panel 17" or 19". I know there are some models that support SOG, and there is also a $25 13W3 -> VGA cable available on Amazon that has dip switches and claims it can adapt the sync signal to work with a regular VGA display. I will need to look into that further and see if anyone has had success using one.

 

[ClassicHasClass]

Do you mean this ( https://www.amazon.com/CablesOnline-SunMicro-Monitor-Switches-W3-606/dp/B0C2MBSLB1 )? I've seen that cable and it will turn the 13W3 into VGA, and it might be able to put some sort of sync on the right line, but I don't think a passive converter will be able to fully filter the sync signal on the green channel. It may work OK with a monitor that can already accept sync-on-green, though there is the risk the picture will have an abnormal green hue as a result (I have an NEC multisync like that). I'm also unsure you would get a proper composite (let alone separated) sync signal from it. I'd be interested to hear how well it works if you end up buying one.

For both my Indy and Indigo2 I use a Software Integrators #7053 active filter that turns the sync signal on green into true composite sync, which most monitors will accept, and emits a clean green channel. The downside of this device is it's active, so it needs power of its own, and it's expensive, about $140. There's a link in the blog (not affiliated, just satisfied, and I own several).