SCSI: Worth Knowing
The SCSI connection has 68 small pins (top). IDE, by contrast, gets by with 40 terminal pins.
A typical Ultra160 SCSI cable has between three and five connectors for drives. Top-class versions have up to 15 of them.
The SCSI specification stipulates that both ends of the SCSI bus have to be terminated, i.e., must have a bus terminating resistor to prevent signal reflections.