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Chapter Overview. Traditional cathode-ray tube (CRT) monitors Flat-panel displays (FPD) Display adapters Choosing and troubleshooting display systems. Basic Monitor Operation. Internal CRT Operation. Screen Resolution and Pitch. Additional Monitor Considerations.
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Chapter Overview • Traditional cathode-ray tube (CRT) monitors • Flat-panel displays (FPD) • Display adapters • Choosing and troubleshooting display systems
Additional Monitor Considerations • The larger the CRT, the more expensive the monitor is. • Higher bandwidth equals greater maximum vertical refresh rate (VRR). • Interlacing (painting alternate rows) saves money but causes eye strain.
Power-Saving Features • Display Power Management Signaling (DPMS) modes reduce power use when the monitor is idle. • DPMS places the monitor in an inactive status if the system is inactive for a specified time. • The inactive states are • On • Standby • Suspend • Off
Monitor Maintenance • Do not work inside a monitor; it is dangerous. • Properly ventilate the enclosure. • Clean the face of the CRT gently. • Do not push the monitor beyond its operating guidelines. • Use energy-saving features.
Monitor Troubleshooting • Check the cables, including the power and display cables. • Check the front panel controls. • Check the display drivers and reinstall them, if needed. • Try another display adapter. • Refer the problem to a specialist.
How Flat-Panel Displays Work • FPDs use transparent organic polymers sandwiched between polarizing filters with some form of backlighting. • An electrical charge determines if light passes or not. • Light-emitting diode (LED) displays have adjoining cells, each with a different color. • Active-matrix displays have largely replaced passive-matrix displays (PMDs).
Emerging Flat-Panel Technologies • Electroluminescent displays (ELDs) • Emit light from phosphors • Have lower-quality color and require higher power usage • Plasma display panels (PDPs) • Work much like fluorescent lights • Use phosphor films to produce a color image • Have lower contrast and brightness and require higher power usage
Installing and Maintaining FPDs • In general, FPDs are installed and maintained the same as CRTs. • You must use a compatible display card. • The operating system must have drivers. • Multisystem switches might be incompatible. • You should wipe the screen with a dry, soft cloth to remove dust. • You should use an uninterruptible power supply (UPS) and/or surge protector.
Early PC Card Display Adapters • Monochrome Display Adapter (MDA) • Color/Graphics Adapter (CGA) • Enhanced Graphics Adapter (EGA)
Video Memory and Processor Demands • The amount of memory determines the amount of color and resolution. • Color depth multiplied by resolution determines the amount of memory needed. • More colors at a higher resolution require more memory and processor power. • Display coprocessors handle tasks that would normally slow down the PC.
Video Memory • Fast page-mode RAM (FPM RAM) • Video RAM (VRAM) • Extended data out DRAM (EDO DRAM) • Window RAM (WRAM) • Synchronous graphics RAM (SGRAM) • Multibank DRAM (MDRAM)
Display Drivers • Text-based adapters under MS-DOS do not require software drivers. • Microsoft Windows, OS/2, and other graphics-rich environments require drivers. • Display drivers adjust the refresh rate, resolution, and other features. • When installing a new card or operating system, you should check the manufacturer’s Web site for the latest display drivers.
Choosing a Display System • Consider the maximum viewable area that you need. • For faster graphics applications, use a fast graphics adapter with VRAM or WRAM. • For multimedia systems, consider TV out, TV tuner, and hardware DVD acceleration. • If desk space is limited, consider an FPD. • Consider the tradeoffs in cost and performance.
Troubleshooting Display Systems • Verify that power and adapter cables are properly attached and that the adapter is fully seated in the expansion slot. • Boot the system. If you get an image but the computer does not load the operating system, suspect memory or drivers. • Reset the card to 640 480 in 16-color VGA mode at 60-Hz refresh. • Make sure you are not exceeding the approved monitor refresh rate. • Try a different display adapter or monitor, or test on a different PC.
Chapter Summary • Resolution is a function of horizontal pixels, vertical lines, and the refresh rate. • Traditional monitors with CRTs have higher resolutions but take more desk space. • FPDs require special graphics adapters. • Monitors enclose very high voltages, which can be lethal. • The video card is the interface between the expansion bus and the monitor. • 24-bit cards with VRAM or WRAM are required for true color.