Philips 201P User Manual

Contents

VVertical dot pitchSee Dot pitch.Vertical scanning frequencyExpressed in Hz, this is the number of fields written to the screen every second in interlaced mode. Innon-interlaced mode vertical scanning frequency is the number of frames (complete pictures) written to thescreen every second (also known as refresh rate).Vertical sync pulsesA train of square shaped waveforms that define the start of a new frame.VESAVideo Electronic Standards Association, a consortium of manufacturers formed to establish and maintainindustry-wide standards for video cards and monitors. VESA was instrumental in the introduction of theSuper VGA and Extended VGA video graphics standards (see Video graphics adapters) with a refresh rate of70 Hz, minimizing flicker and helping to reduce operator eyes fatigue and stress.Video dot rateSee Dot rate.Video graphics adaptersA card equipped with a character or graphic generator and video memory, which maps to the screen. Amicroprocessor scans video memory and translates bit information from the computer into displayable videosignals for the monitor. These cards comply with various standards that determine the nature and quality ofthe display.VGA (Video Graphics Array), introduced in 1987, was the first analog card. It offered still higher resolutionthan EGA: 640 X 480 pixels for graphics and 720 x 400 pixels for text, and a color palette of 256 colors. VGAcould also emulate EGA and CGA.Super VGA, devised by VESA in 1989, offers a resolution of 800 x 600 pixels.Extended VGA, introduced by VESA in 1991, offers a top resolution of 1024 x 768 pixels (non-interlaced) anda refresh rate slightly higher than IBM's XGA 8514A.High-end, graphics adapters, introduced over the last three years for professional workstations, offer topGlossaryfile:///D|/rita/LF2/LF2/LFa1/multi_manual/english/GLOSSARY/GLOSSARY.HTM (17 of 18) [8/29/2001 3:14:04 PM]