SCSI Basics

SCSI is based on an older, proprietary bus interface called Shugart Associates System Interface (SASI). SASI was originally developed in 1981 by Shugart Associates in conjunction with NCR Corporation. In 1986, a modified version of SASI that provided a beefier, open system was ratified by the American National Standards Institute (ANSI) as SCSI. There are several benefits of SCSI:
• It's fast -- up to 160 megabytes per second (MBps).
• It's reliable.
• It allows you to put multiple devices on one bus.
• It works on most computer systems. There are also some potential problems when using SCSI: • It must be configured for a specific computer.
• It has limited system BIOS support.
• Its variations (speeds, connectors) can be bewildering.
• There is no common software interface. People are often confused by the different types of SCSI. You'll hear terms such as "Ultra," "Fast" and "Wide" used a lot, and sometimes in combinations. In the next section, you'll find out about the SCSI variations.