Chapter 24. Display Systems

Seeing is believing. If you couldn't see the results of your calculations or language manipulations, the personal computer would be worthless as a tool. You need some way of viewing the output of the computer system to know what it has done and why you're wasting your time feeding it data.

Out of all potential technologies for giving you feedback about what your computer is doing, the one almost universal choice is the one you see on your screen. But it's what goes on behind the screen that really counts. The screen just shows you the results of a lot of technologies and systems working together.

The total entity made from these technologies is your computer's display system. At the hardware level, it comprises two distinct parts . The display is the screen you see, either as a separate monitor or as a panel that's a permanent part of your computer. The display adapter , which may be a separate expansion board or built in to your system's motherboard, converts the logical signals in your computer to the form digestible by the display.

The first display systems used by personal computers were based on television sets. In fact, many were television sets, adapted to the job with a modulator that turned video signals from your computer into Channel 3 or 4. Today's display systems are vastly more sophisticated than mere television sets, often having greater resolution than is promised by even High Definition Television (HDTV) systems. But at heart, computer display systems remain video systems, based on the same technologies as the lowly TV.