>>Always did find it amusing how TV and movie computers seem to have incredibly long lifespans -- often on the order of centuries or even millennia.

That would mostly depend on its fan club. Any fans are doomed to lose their bearings (balls included) sooner or later.

That idea alone suffices to make it SF - computers are no scientific miracle anymore, but a computer lasting a few centuries (even if it's by rebuilding itself periodically) would be. Just like the old joke about missionaries in the kettle, ready to be cooked for cannibals' dinner, as a last resort pull a lighter from a pocket and suddenly have a fire in their hands. The cannibals are not amazed that they made fire, but at seeing a lighter which lights up on first strike.

>>But it only takes a bit of illogic or contradiction to cause them to fail spectacularly in a shower of sparks. Of course, if such computers had some form of AI, I'd imagine they could "go a bit peculiar" like Holly in "Red Dwarf" simply go mad like Box in "Logan's Run"

That was a funny passtime of authors from Asimov to uncounted others for a few decades, that computers (even the positronic brains) would be capable of understanding english while strictly sticking to the logical thinking :facepalm:...

>There's that often-seen theme in SF stories that involve a journey of a "slowboat" (with travel time measured on the order of centuries) finally arrives at its destination, only to have the crew (either original crew that had been put into suspended animation, or perhaps descendants of the original crew) discover that the planet has already been colonized - by Earth. The explanation given is only a few decades since the launch of this probe, some form of FTL is perfected that allows later ships to arrive much sooner. As for the reason why the ship was allowed to continue with the long journey, it was apparently presumed lost because of loss of telemetry from an equipment failure.

There are other scenarios - that the nth generation on the ship would be completely bonkers, that they would be reduced to savagery or develop a religion which doesn't know any world outside the ship etc etc. And the ship wouldn't be quite intact at the time, just functional enough. Also, there were various scenarios about the computer itself - just consider the "Destination void" tetralogy by Frank Herbert, where the crew (one among perhaps thousands) is put under pressure, on a ship which is falling apart but has a lot of spare equipment, to build an AI, which then concludes that it is a god...