Why are computers not displayed accurately in movies?

Why are computers not displayed accurately in movies. In most movies I have seen, computers are not displayed accurately. In almost every one, the computers use a totally unrealistic operating system. Why the extra trouble. The studios must spend much extra money creating these faux operating systems. Another thing is the sounds that a computer makes. Even in movies today, each keystroke corresponds with a beep or blip sound made by the computer. Sometimes it almost sounds like a teletype machine.

As I sit in front of my computer, I see: a black background, a WWW browser (of course!), a clock, a calendar and a window with text in it. Not very eye catching! I would guess that about 95% of all computers in this country involved with business show pretty much the same thing. Now sometimes, my computer has beautiful astronomical images displayed too, but after a few seconds a movie audience would lose interest in that as well. So Hollywood feels the need to spiff it up a bit.

When I read your question, the first thing I thought of was the scene near the end of "Jurassic Park" where the young girl is "hacking" her way onto the computer to restart the park's automatic systems and to get the door to lock. Deadly raptors are at the door, and Our Heroes are bravely trying to keep them out. With everyone screaming and on the edge of panic, she is able to use an operating system with amazing 3D graphics to get the control room back on line. At one point, she mutters, "Unix. I know this." It sure didn't look like any Unix OS I have ever seen!

This scene was done that way to be dramatic, and not for any kind of scientific accuracy (if you want scientific accuracy, you've got the wrong movie!).

Note added March 24, 1998:A few people have pointed out to me that the OS she used is an actual gee-whiz type interface available for SGI computers. Technically, I was right: I had never seen such a thing! But for bookkeeping sake, I point out here that the movie got that part right!

As for keyboard clicks; most people get rid of that option as fast as they can! It annoys everybody. But again, it helps in a movie to add a little pizzazz to the action. It may not be technically accurate, but it does seem to help. Think of it this way: the next time "Star Trek" is on, turn the sound off during the space scenes. There is no sound in space, but "Star Trek" sure seems funny without it!