Upgrading and Repairing Servers

SCSI-1 was the first implementation of SCSI and was officially known as ANSI X3.131-1986. The major features of SCSI-1 are as follows:

• 8-bit parallel bus

• 5MHz asynchronous or synchronous operation

• 4MBps (asynchronous) or 5MBps (synchronous) throughput

• 50-pin cables with low-density pin-header internal and Centronics-style external connectors

• Single-ended (SE) unbalanced transmission

• Passive termination

• Optional bus parity

SCSI-1 is now considered obsolete; in fact, the standard has been withdrawn by ANSI and replaced by SCSI-2.