SGI Indigo2 graphics options

[Jules Richardson]

Amongst other things, I picked up a SGI Indigo2 system yesterday. It turned 
out that it had the original packaging, and that it's an Impact 10000 machine.

For graphics however it has a four-board set; does anyone know what this 
might be? Wikipedia talks about a three-board set for the Maximum Impact, 
and fewer cards for lesser options, but I've not seen mention anywhere of a 
machine using four (unless they're just not counting the analog output 
board as part of the three?)

I'm not sure what it has for RAM; all of the sockets are filled. Someone 
had scribbled 32MB and 1GB of disk on the box, but it has 2 x 4GB drives 
fitted, so that's not necessarily correct.

I need to clean the dust out before I try powering up, but does anyone know 
what a minimum config would be? Can I power up with no disks and 
framebuffer, and expect to get a serial console? I'd like to not stress the 
PSU (or risk the framebuffer cards) initially if possible - the previous 
owner said they never ran it, although it was supposedly working when they 
got it.

cheers

Jules