CIA (Complex Interface Adapter, though I suspect this acronym was invented retroactively), Mostech 6526, is a chip in Commodore 64 that handles I/O.

Actually, there's two of these chips on C64 motherboard. CIA 1 ($DC00 and onward) handles keyboard and joysticks, and CIA 2 ($DD00 and onward) handles serial bus and user port.

CIA 1 also controls the timer interrupt (IRQ interrupt), which also makes it a pretty interesting chip from programmer's point of view...

Also an Amiga group founded on Stord, Norway in the beginning of the nineties. Was locally famous for their lack of knowledge in the Amiga scene, as only a few of the 50+ members knew much more than how to use XCopy Pro to copy games.

CIA was an acronym for "Crackers International Association", but was changed to "Computerusers International Association" when the members realized that

1) Cracking was beginning to get a bad rep
and
2) None of the members had the faintest idea how cracking actually was done

CIA managed to get economic support from the local government though, to help fund some arrangements. These were tournaments, mainly in the game "Kick Off 2".

In 1997 the interest faded, the members had "grown up" and CIA was disbanded. The money the group had amassed was given to charity.

---

CIA may not have made the biggest impact on the Amiga scene, but the members had jolly good fun while it lasted.