BIS, I think, stands for something like "improved" or some
such thing. For example, there is a version of the old Mig-15
known as the BIS. Since this is an early 50's aircraft, I doubt
that Binary In Store is what the designation stands for.
Also, you are right about the computers having little
to do with current technology. Digest Group, who for all practical
purposes is writing the Traveller rulebook these days, has found
away around this by saying that all systems are triplicated, and that
is why they are so large. Seen the Starship Operator's Manual
for more information.
Jim Cunningham
High Passage Founder
Traveller Relic