I've dealt with looking for Galileo spacecraft information: www.retrotechnology.com/galileo/galileo_1802.html www.retrotechnology.com/memship/galileo.txt www.retrotechnology.com/memship/1802_spacecraft.html ...because of its RCA COSMAC 1802 processors. In the past it was a challenge to find technical details of 20th century spacecraft, because of fears of hacking; because it was on paper and not electronic media; because few were interested. In the 21st century, so much info is thrown online now, and a lot of archives get digitized. So what's not online today, may be online tomorrow. I'd say, Web search from time to time. But if you have a strong interest, find out where the former engineers for the project hang out on the Web, and see if they can point you to more resources. Don't wait too long: these guys/gals won't last forever. The Galileo spacecraft used several 1802's for its instruments, and I believe it had a bus architecture for communicating to some other 1802's for communications, data archiving and so on. It won't be a simple architecture or simple software. Chances are, there were professional journal publications in the era, which described the general architecture. I may point to some of them on my Web pages. If you find a good resource, let me know, I'll add it to my Web site. Herb Johnson William O'Neil Research Base Juno, Jupiter