I'll give a quick rundown of what I did to get this working and add a couple of pictures...but this project isn't quite complete. As you'll see in my pictures, I currently have an HP bench power supply hanging off of my X-Brick, which isn't necessarily conducive to placing it in my short rack. I plan on finding a 48v->24v DC/DC converter at some point that I can integrate directly into the X-Brick for a much cleaner installation. If anybody has any suggestions where I could find such a beast for cheap, I would be very excited to hear about it...Anyway, without further ado, here's what I did:
Of course the first thing I did was a lot of research on the topic. There have been a few posts here and there on the forums about trying this, but I hadn't seen anybody actually do it. tjsgifan mentioned in a thread somewhere that it may not be possible because the X-Brick doesn't supply 24v to the installed XIO boards, which the VPro boards require. I wanted to confirm this and map out the pinout of the power connector for XIO boards before I went any further, so I pulled one of my Octanes apart and put it back together outside the metal housing so I could have access to the back side (or is it front side? wherever the solder joints are...) of the frontplane. I used my multimeter to map the pinout of one of the power connectors with an XIO board installed. Indeed, there were four pins out of 80 that supplied 24v to the XIO board. I will make up a nice graphic with the complete pinout on it for interested parties
After getting the pinout, and after receiving my X-Brick from zerolapse, I went ahead and checked the pinout on the X-Brick. As tjsgifan had pointed out, there wasn't 24v anywhere to be found on the XIO power connector. I went ahead and tried out my V6 in the X-Brick to see if it would just work anyway...and there was no luck. There was a message about a Widget being present, but the link was down. I saw this as good news, because at least the X-Brick recognized that a VPro was there, even if it wasn't able to bring it up. After this, I did some more probing and found that the four pins that should have been providing 24v weren't connected to anything at all. This was good news, because nothing would prevent me from putting 24v on them by other means (i.e. if they were tied to ground, putting 24v on them would most certainly cause epic failure). At this point I entered into MacGyver mode...
I wanted to attach a power supply directly to these pins to supply 24v, however the pins were awfully small and difficult to access. I probably could have done it, but I didn't want to risk shorting something else out in the process, so I decided to solder a extension onto those pins to make it easier to attach things to them. I went to the University of Illinois' electronic component superstore (holla to my ladies down at the ECE storeroom!) and bought some of these. I separated the pins from the strip and removed the plastic, leaving just the metal barrel and pin. I then heated the barrel up with my soldering iron and filled it up with solder. I took the pin and turned it upside down so the opening of the barrel was facing down and place it over the pin on the midplane I wanted to extend, and then heated the barrel with my soldering iron until the solder liquefied and the barrel dropped down over the pin on the midplane. Once the solder was cool, I had a much larger pin to attach leads to. This is what it looked like when it was all finished and I had attached leads to it:
After that modification, it was just a matter of running the leads to my bench supply which was set to 24v and power the whole system on. The error message about the Widget went away, and in the command monitor I ran a hinv...and the graphics board was detected! I went ahead and booted into Irix, but the board was no longer showing up in the hinv. I mostly expected this, because as an Origin, it had no graphics subsystem installed. I rebooted and played around with the software installation and managed to get the graphics subsystem installed and the V6 then showed up in the hardware inventory of Irix, but X still did not start. INST listed my machine as being an "Onyx3 InfinitePerformance, Fuel", so I knew I had to be on the right track. /usr/gfx/gfxinfo even listed the board, but it claimed that it was "unmanaged". I decided that this was probably the problem after consulting the search feature of nekochan. At this point I was ready to do a fresh install because I didn't want to mess around anymore...which I eventually got around to this morning (stupid friends peer pressuring me into going out for drinks on friday night
).After a fresh install and a reboot, I still had no graphical boot screen...and I was feeling mighty discouraged. I went ahead and booted the system anyway and much to my delight, a login window popped up on my screen! After some adjustments to the native resolution, I have a working Onyx3 InfinitePerformance system! I then went back and set "console=g" and lo and behold, I got a graphical boot screen. Unfortunately, it always reverts to "console=d" after a power cycle. Another interesting phenomenon...on the graphical boot screen it just says "Welcome to" with nothing under it, instead of "Welcome to Onyx3" or whatever it should say. Any suggestions on how to remedy these two minor issues?
Here's the hinv.
And here are a few pictures of the Onyx3 goodness, and my precarious external power supply solution:
x2+ 
x3 
x2 
x3 