Word processors never display a cursor.
You never have to use the space-bar when typing long sentences.
All monitors display inch-high letters.
High-tech computers, such as those used by NASA, the CIA, or some such governmental institution, will have easy to understand graphical interfaces. Those that don't, have incredibly powerful text-based command shells that can correctly understand and execute commands typed in plain English (e.g. "LETS PLAY GLOBAL THERMONUCLEAR WAR" ex. "War Games")
Corollary: you can gain access to any information you want by simply typing "ACCESS ALL OF THE SECRET FILES" on any keyboard.
Likewise, you can infect a computer with a destructive virus by simply typing "UPLOAD VIRUS" (ex. "Fortress").
All computers are connected. You can access the information on the villain's desktop computer, even if it's turned off.
Powerful computers beep whenever you press a key or whenever the screen changes.
Some computers also slow down the output on the screen so that it doesn't go faster than you can read.
The *really* advanced ones also emulate the sound of a dot-matrix printer.
All computer panels have thousands of volts and flash pots just underneath the surface.
Malfunctions are indicated by a bright flash, a puff of smoke, a shower of sparks, and an explosion that forces you backwards.
People typing away on a computer will turn it off without saving the data.
A hacker can get into the most sensitive computer in the world before intermission and guess the secret password in two tries.
Any PERMISSION DENIED has an OVERRIDE function (ex. "Demolition Man", and countless others).
Complex calculations and loading of huge amounts of data will be accomplished in under three seconds.
Movie modems usually appear to transmit data at the speed of two gigabytes per second.
When the power plant/missile site/whatever overheats, all the control panels will explode, as will the entire building.
If a disk has got encrypted files, you are automatically asked for a password when you try to access it.
No matter what kind of computer disk it is, it'll be readable by any system you put it into. All application software is usable by all computer platforms.
The more high-tech the equipment, the more buttons it has (Aliens). However, everyone must have been highly trained, because the buttons aren't labelled.
Most computers, no matter how small, have reality-defying three- dimensional,active animation, photo-realistic graphics capability.
Laptops, for some strange reason, always seem to have amazing real-time video phone capabilities and the performance of a CRAY Supercomputer .
Whenever a character looks at a VDU (video display unit), the image is so bright that it projects itself onto his/her face (see "Alien", "2001").
And of course, everyone can type 95+ words per minute with no backspacing!