Page 10      Diablo Blue      February, 2001

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The video cards can run in different video mode based primarily on memory limitations. The modes vary in resolution (dots across by dots down) and the number of colors. The more colors, the more realistic the images will be. The color depth at any given resolution is limited by the memory on the card. The number of colors fills up the memory at the following rates:
16 Colors = 0.5 Bytes per Pixel
256 Colors = 1 Byte per Pixel
High Color = 2 Bytes per Pixel
True Color = 3 Bytes per Pixel
Use that number in that following calculation to see the amount of memory used for that setting: Horizontal Resolution x Vertical Resolution x Bytes per Pixel = Amount of Ram Required (in bytes). If you want to run at True Color with a resolution of 1600 X 1200, your video card must have 5.6 MB of video RAM (1600 x 1200 x 3 = 5,760,000 bytes).

Video Interface

If you are happy with the settings available on the video card in the computer you probably do not care how the computer talks to the video card. You will care only if you ever expect to replace it.
Check to see if the existing card can be removed, or at least disabled. Many of the low-end computers will have the video built into the motherboard. You may be able to tell by looking at the back of the computer. If all the connectors are in line with each other (including the video port), the video is definitely on the motherboard. In my research, I found that most of the video cards interface through a special bus known as AGP (Accelerated Graphic Port) rather than PCI. Be sure that there is an AGP slot available if you expect to change the video. Note that there can still be an AGP slot even though the video is built into the motherboard. AGP is a special interface developed by Intel that provides a much faster communications channel. In addition, AGP allows 3-D textures to be stored in main memory rather than video memory. This is why you will see shared video memory in some specifications.

Your computer will include several connectors for external devices. These connectors are called data ports. The standard ones you should expect to find are keyboard, mouse, serial, printer, USB, network, and telephone. In most cases, the data is transmitted one bit at a time (or serially). The printer port is one exception -- it transmits multiple bits at one time (or in parallel).
Most name brand computers will color code the ports and the cables that connect to them. This way you just match up the colors. It works well for everyone except the colorblind.

Keyboard and Mouse Ports

The keyboard and mouse port use identical-looking small round connectors. It is easy to get them confused. The good news is they are actually interchangeable; the computer will figure out which device is plugged in where. These ports are normally built into the motherboard.

Printer Ports

There is normally one parallel printer port on a computer, referred to as LPT1. This is designed to provide a high-speed link to a printer. It uses a 25 pin D-type connector. Be aware that unless the computer includes the printer, the system will not include a cable to connect to the printer. There is an inexpensive parallel cable that is available for inkjet printers and a relatively expensive one used for laser printers. There is normally one of these ports built into the motherboard. Additional printer ports normally require an expansion board. Windows supports up to three parallel ports. If you need more parallel ports, you can add more through USB converters.
You may end up connecting to the printer via a USB port instead. This port can also be used for connecting devices like scanners, zip drives, and netcams. Some expensive software utilizes a small device (called a dongle) to protect the software from unauthorized use; these connect to this port.

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