Oh, jeeze, I HAVE that photo somewhere! If I could only remember where the hell it is. It was attached to an article about how Lucas had pioneered this bizarre electronic gizmo that would let you edit a film non-linearly. I wonder what ever happened to that idea? Oh yeah...it became the ONLY way to edit.
Anyways...I think..I THINK it's from Discover magazine from '84, in a cover article called "Computerizing the Movies". I'll poke around, but I think my copy is stuffed away somewhere at my parents place. That should give you a starting place at least.
Hah...just found the text online, and it goes on to talk about this other computer he's developed which can produce animation, and is called a 'Pixar'. The other tech is some esoteric piece of hardware for mixing audio that probably never went anywhere, called an ASP. Jeesus, to hell with the haters - Lucas is a damn visionary.