Today's computers have an almost overwhelming number of connectors and sockets that allow a wide variety of devices to exchange information with the processor. You can expect any new computer to have many of the inputs and outputs listed in Table 3.1 unless you're buying a very compact system with limited capabilities. However, some systems use several USB ports in place of the dedicated printer, mouse, keyboard, and other individual connectors.
Connector Name | Description |
---|---|
Power | AC or DC power input |
Monitor | Output to video display |
Printer, LPT, or Parallel | Interface to a printer, scanner, or other parallel device[*] |
Serial or COM | Serial data interface[*] |
Modem | Interface to the public telephone network |
Ethernet or LAN | Interface to Local Area Network |
PS/2 Keyboard | Input from keyboard[*] |
PS/2 Mouse | Input from mouse or other pointing device[*] |
USB | Input and output to Universal Serial Bus devices |
IEEE 1394 | Input and output to FireWire devices |
Video | Output to a television set |
PC Card | Socket for a PCMCIA card (most common on laptops) |
Microphone | Audio input from a microphone |
Line In | Audio input from a high-level source |
Line Out (L & R) | Audio output to speakers (Left & Right) |
Headphone | Audio output to headphone |
Docking | Combined inputs and outputs to a docking station or port replicator (laptops only) |
Infrared or I/R | Data port for infrared data transfer (most common on laptops) |
Digital Media | Socket for one or more types of flash media card |
[*]Many new computers use the USB ports in place of these connectors. |
The exact location of many connectors-front, back, or sides of the case-is purely a matter of convenience. As long as they work properly, the precise location of most connectors and controls makes no difference to the computer's performance. If you have a choice, look for a desktop computer with at least one or two USB connectors on the front panel; connecting and disconnecting portable devices like flash drives and digital cameras to the front panel is much easier than reaching around to the back of the case.
Note | There are no universal symbols to identify input and output connectors. A few are commonly used among different manufacturers, but you should look in your manual for the symbols on your computer. |
CROSS-REF | Look for explanations of the devices that connect to all these connectors in Parts II, III, and IV of this book. |