Are there no computers in airliners?
I remember that they had computer screens and stuff in that movie Die Hard, to show altitudes and maps and directions...It was that sequel one, where the German guy's brother tries to take revenge.

Yeah, all the new airplanes have it. But we had airlines before computer was invented. And they would have had maps and instruments to show altitude, directions and pressure too. I mean, all you need is an altimeter and a barometer.

But they used commercial planes to get to Prague...that means things like lights, heating, air conditioning...which is usually controlled by a computer.

You wouldn't need too much equipment for a little 2 seater plane for an aviator enthusiast, but for commercial flights taking off from airports, there has to be some sort of mechanical calculating machine.

Er, why do we need computers for lights, heating and air-conditioning? Sure, using them would make operating easier, but it is not like they can't run without a computer. The very first airline had heating and lighting - http://en.wikipedia.org/wiki/Airliner#History. And that was in 1913.

Yeah, what she said. It's entirely possible to build a pretty comfortable airliner with no computers on board. They are, of course, ubiquitous on modern airliners, but that doesn't mean they're required.

A commercial plane doesn't actively need any more instruments than a two-seater light aircraft, they just have them for safety reasons. Instrument landing systems, autopilots, fly-by-wire controls, cleverer status monitoring, etc all make it easier to follow ATC-directed flightpaths and cope better with bad weather and other problems, but they're by no means required.