Copyright © 2007 Heathkit Company, Inc. All Rights Reserved PC Fundamentals Presentation 40 – Displays and Resolution

2 Objectives At the end of this presentation, you will be able to:

3 Define each of the following in terms of resolution: QXGA, UXGA, SXGA, XGA, SVGA, VGA, EGA, and CGA. Define the following display terms: Screen size, aspect ratio, resolution, interlace, refresh rate, dot pitch, and pixel. Explain how the number of pixels affects the size of the letters displayed on a screen. Explain the difference between the triad pattern and bar pattern of phosphor used on the face of a CRT.

4 Measuring Screen size Screen size is measured diagonally.

5 Aspect Ratio = Horizontal Size Vertical Size Horizontal Size Vertical Size

6 Super VGA (SVGA) The standard for PCs and monitors. Popular SVGA formats include: – 800 by 600 pixels – 1024 by 768 pixels – 1280 by 1024 pixels The higher the resolution, the finer the detail displayed. The higher the resolution; the more information displayed.

7 Video Graphics Array (VGA) Resolution of 640 by 480 pixels. Introduced in 1987 by IBM as the PS/2 First to use analog video outputs. First to use square pixels so vertical and horizontal lines have the same thickness. Replaced by SVGA in most applications.

8 Enhanced Graphics Adapter (EGA) Resolution of 640 by 350 pixels. Introduced by IBM in 1984.

9 Color Graphics Adapter (CGA) Resolution of 320 by 200 pixels. Introduced with the original IBM PC in The first of the IBM color adapters for the PC.

10 Evolution of Video Display Adapters 1981CGA320 by EGA640 by VGA640 by SGA800 by 600 XGA1024 by 768 SXGA1280 by 1024 UXGA1600 by 1200 QXGA2048 by 1536

11 SVGA VGA

12 Video Mode changes things... Screen resolution Screen refresh rate Amount of video RAM needed

13 The Screen Resolution Resolution Colors 640 x 48016, 256, 32K, 64K, 16 Million 800 x , 32K, 64K, 16 Million 1024 x , 32K, 64K, 16 Million 1280 x , 32K, 64K, 16 Million 1600 x , 32K, 64K, 16 Million 2048 x , 32K, 64K, 16 Million

14 The Screen Refresh Rate 43 Hz 60 Hz 72 Hz 75 Hz

15 Interlaced Mode 60 Hz

16 Resolution vs. Monitor Size Monitor Size 13-inch 14-inch 15-inch 17-inch 21-inch Max Resolution 640 x x x x 1200

17 The Video Palette Foreground Color code 0110 Foreground Color code 0110 Background Color code 0001 Background Color code 0001

18 Amount of VRAM Needed Mode Rows x Columns Colors Memory Text 24 x x bytes Graphics 640 x K bytes Graphics 640 x K bytes Graphics 640 x K 1024K bytes Graphics 640 x Million 1024K bytes Graphics 800 x K bytes Graphics 800 x K bytes Graphics 800 x K 1024K bytes Graphics 800 x Million 2048K bytes Graphics 1024 x K bytes Graphics 1024 x K bytes Graphics 1024 x K 2048K bytes Graphics 1024 x Million 4096K bytes continued...

19 Amount of VRAM Needed Mode Rows x Columns Colors Memory Graphics 1280 x K bytes Graphics 1280 x K bytes Graphics 1280 x K 4096K bytes Graphics 1280 x Million 4096K bytes Graphics 1600 x K bytes Graphics 1600 x K bytes Graphics 1600 x K 4096K bytes Graphics 1600 x Million 8192K bytes

20 Dot Pitch and Pixels Dot Pitch Pixel 0.26 mm, 0.28mm, 0.31 mm or 0.34 mm Phosphor Color Triad Phosphor Color Triad

21 Pixel

22 The Effect of Pixel Size 6 x 8 pixels 10 x 12 pixels

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28 Fully Half None Level of Illumination

Levels of Red

30 Superimposing Images Superimposing Images

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32 Triads

33 Color Bars

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35 Pixel

36 The LCD Display The LCD is rapidly becoming the most popular display technology. LCDs offer several advantages: – Flat display area – Low power – Larger viewable area – Take up less space LCD displays do not: – Emit electromagnetic radiation – Have high voltages present in the chassis.

37 Generally more expensive than comparable CRT display. Resolutions can be less than a comparable CRT. Disadvantages

38 Available for both desktop and notebook. Two common LCD technologies: – Active-Matrix Analog is common on smaller low cost displays – Active-Matrix Digital is used in larger high-end displays.

39 LCDs use a unique material called liquid crystal. Liquid Crystal has properties similar to water and crystal. By applying a voltage, the amount of light can be controlled. Color LCDs use color filters to create the color display.

40 Transparent Glass Plate Liquid Crystal Molecules Transparent Electrode

41 Components of the color LCD display include: – A liquid crystal panel – A backlight as a light source – A thin film transistor (TFT) array – Polarizing filers on both sides of the display.

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43 More difficult to switch resolutions. Analog LCD panels can use existing video card and connector. LCD may not have sufficient color depth. Many don’t react as quickly as CRTs. Consider before selecting an LCD

44 Large screen LCD monitors are becoming a real display option. LCD monitors offer several advantages: – Larger effective viewing area – Produce a higher precision image – Flexible mounting options – No electromagnetic emissions.

45 Evaluate panel at native and other required resolutions. – Does existing video card support required features? – Support for analog and DVI inputs? – Contrast ratio high enough? Is an LCD suitable?

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