Video capturing from different video sources (Sun, SGI, etc)

Hey all; I've been wanting to do some video capturing from an SGI and have been trying to work out the 'best way' (or, perhaps, the EASIEST way) of doing it. The video I'm capturing is prior to the OS coming up (waffling around the Command Monitor, etc), so I can't have the system itself help me out. If I had some LCD panels which spoke SGI I would simply sit a DV cam in front of the LCD and record it - the quality should be acceptable - but I don't (LCD since CRTs would have flicker, of course, when recorded). Plus, I'd quite like to source video from Suns and other machinery. I imagine there really -isn't- a catch-all solution, but I'd love to have the thoughts of the Geek Masses. I've never done video capture before in any form, and have little experience with working with video at all to be honest, so anything would help. Many thanks; - JP