SCSI Configuration Jumpers
SCSI hard disks are equipped with much more sophisticated controllers than IDE/ATA drives and have more jumpers to be set in order to control operation. There is also a likelihood of it varying much more based on manufacturer or model. The following are the most common and important SCSI drive jumpers:
SCSI Device ID
For the purpose of addressing, every device on a SCSI bus must be uniquely identified. Narrow SCSI drives have a set of three jumpers, which are used to assign the disk an ID number from 0 to 7 whereas a wide SCSI drive has four jumpers to enable ID numbers from 0 to 15.
Termination Activate
For proper functioning it is necessary that the devices on the ends of the SCSI bus must terminate the bus. If the hard disk is at the end of the bus, setting this jumper will cause it to terminate the bus for proper operation.
Disable Auto Start
When present, this jumper will inform the drive not to start automatically. Instead it will wait for a start command over the SCSI bus. This is usually followed to prevent excessive startup load on the power supply. However, some manufacturers invert the sense of this jumper by disabling startup by default and by providing an "Enable Auto Start" jumper instead.
