Datasheet

62 Chapter 1
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Hardware
PS/2 (Mini-DIN) A round connector with six small pins inside, commonly used to connect
keyboards on ATX motherboards or PS/2 style mice.
DIN A larger round connector with five rather large pins inside, used for connecting the
keyboard on an AT motherboard.
USB A flat rectangular connector, used with USB interfaces.
Cabling
Cables are used to connect two or more entities together. They’re usually constructed of
several wires encased in a rubberized outer coating. The wires are soldered to modular
connectors at both ends. These connectors allow the cables to be quickly attached to the
devices they connect.
Cables may be either shielded or unshielded. This refers to shielding against electromag-
netic interference (EMI); it has nothing to do with whether the cable is shielded against dirt
or water.
A list of common cable types used in PCs, their descriptions, their maximum effective
lengths, and their most common uses is given in Table 1.7. The F or M in a connector’s
designation is for female (holes) or male (pins).
TABLE 1.7 Common PC Cable Descriptions
Application 1st Connector 2nd Connector Max. Length
Null modem DB-9F DB-9F 25 feet
Null modem DB-25F DB-25F 25 feet
RS-232 (modem cable) DB-9F DB-25M 25 feet
RS-232 (modem cable) DB-25F DB-25M 25 feet
Parallel printer DB-25M Centronics 36M 10 feet
External SCSI cable Centronics 50M Centronics 50M 10 feet (total SCSI
bus length)
VGA extension cable DB-15M DB-15M 3 feet
UTP Ethernet cable RJ-45M RJ-45M 100 meters
Thinnet Ethernet cable BNC-M BNC-M 100 meters
Telephone wall cable RJ-11M or RJ-14M RJ-11M or RJ-14M N/A
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