SCSI is a flexible I/O bus that is used in the design of a wide variety of peripherals, including disk drives, CD-ROM drives, tape drives, scanners, and magneto-optical drives. The SCSI host adapter is the circuitry that serves as an interface between the system and one or more SCSI peripherals. A host adapter can be a card that plugs into the system's expansion bus, such as a PCI card, or it can be designed directly into the system board.
The Plug and Play SCSI Specification lists the requirements for SCSI devices that create an easy-to-use environment for the user. In addition, enabling or disabling the termination on peripherals and other variables that require physically changing peripherals must be as simple as possible for the user.
The use of SCSI in a PC 97 system is optional, but if SCSI is used, all components must comply with the requirements defined in this chapter.