| Video Graphics Specifications |
| Creator : | IBM |
| Year Introduced : | 1987 |
| Video Standard : | VGA - Video Graphics Array |
| Horizontal Frequency : | 31.5 kHz |
| Vertical Frequency : | 50-70 Hz |
| Video RAM : | 256-512K |
| Maximum Colors : | 256 |
| Maximum Resolution : | 640x480 |
| Starting Address : | A0000 |
| Connector Type : | DB15 |
| Video Signals : | 3 Analog |
| Status : | |
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| Video Graphics Array |
VGA monitors are designed to use analog signals rather than digital signals to drive the CRT guns. Digital signals limit the maximum number of colors that can be displayed to 16. By using variable (analog) signals to drive the CRT guns, current video adaptersand monitors are capable of displaying over 256,000 colors. The super VGA and XGA monitors also use analog signals. If you are upgrading your monitor, be sure that the display adapter is compatible with the new monitor. Also, there are multiscan or multisync monitors that can be used with a variety of video cards.
These monitors detect the rate that data is being received and adjust their scan rates to match the input. As you can see, the type of monitor you have must be compatible with the type of video card in the computer. You can literally burn up a monitor by plugging it into the wrong type of video card. Video monitors require very little preventive maintenance. They should be cleaned periodically to remove any dust that has collected on the components. Repair of a failed monitor is difficult because the monitor diagrams are hard to obtain from the manufacturer. Also, the price of the repair parts often exceeds the cost of a new monitor.
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| DB-9 pins for VGA |
|---|
| Pin | Description |
|---|
| 1 | Red Video |
| 2 | Green Video |
| 3 | Blue Video |
| 4 | Horizontal Sync |
| 5 | Vertical Sync |
| 6 | Red Ground |
| 7 | Green Ground |
| 8 | Blue Ground |
| 9 | Sync Ground |
| C A U T I O N |
| Never run your monitor out of spec. If your display is screwed up, there's a good chance that the frequencies are out, so turn off the monitor! |
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