The SCSI port is used to connect peripheral devices to a Macintosh. Apple recommends that the first and last devices are terminated. Shareware programs like SCSI Probe, SCSI Tools and SCSI Evaluator allow you to view what is connected on the SCSI chain. They are useful programs for making SCSI devices mount. Many SCSI devices can be connected together with a standard 50 pin to 50 pin peripheral SCSI cable.
SCSI terminators are plugs that fit into SCSI ports.
Their function is to keep signals from echoing back and forth along the SCSI cabling. There will be problems with echoing with a faster Macintosh, increased number of connected SCSI devices, longer cable lengths, and SCSI devices located too near another. Some SCSI devices have a termination switch for terminating the SCSI device. These devices do not need SCSI terminator plugs for termination. SCSI devices that are self terminating must be the last SCSI device on the chain.