SCSI Cables and Connectors
SCSI devices use a variety of connectors. Until recently, there was little standardization, and no way to judge the SCSI standard of a device by looking at its connector. For example, current U2W devices use the 68-pin high-density connector, but that connector has also been used by old Digital Equipment Corporation (DEC) machines for single-ended devices. By convention, all SCSI devices have female connectors and all SCSI cables have male connectors. This rule is generally followed by modern SCSI devices intended for use on PCs, although it is frequently violated by very old PC devices and by devices intended for use outside the PC environment. Mainstream SCSI devices use the following cables and connectors:
- DB25 SCSI connector
Some scanners, external Zip drives, and other Narrow SCSI devices use the DB25 SCSI connector, also called the Apple-Style SCSI connector. Unfortunately, this is the same connector used on PCs for parallel ports, which makes it easy to confuse the purpose of the connector on the PC. Devices are linked using a straight-through DB25M-to-DB25M cable.
Warning
Avoid using DB25 SCSI connectors if possible. Connecting a SCSI device to a parallel port or a parallel device to a SCSI port may damage the device and/or the interface. If you must use DB25 SCSI, make sure all ports are clearly labeled.
- 50-pin Centronics SCSI connector
The 50-pin Centronics SCSI connector is also called the Low-density 50-pin SCSI connector or the SCSI-1 connector ...
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