SCSI Integration Checklist
Š All devices, including the initiator, on a bus must be unique.
Š It is advisable to have the boot device as ID 0.
Š Both ends of a SCSI bus (cable) must be be terminated using active terminators.
Š In practise this can be achieved using either discrete terminators or the internal
terminators often provided within the controller and attachable devices.
Š NO termination is allowed at points along the cable. So any device attached (that is
not at the end) must have internal termination disabled.
Š In the situation where the controller has multiple SCSI ports with differing
performance ALL ports must be correctly terminated.
Š In a situation where the controller has a common port with internal and external
connections and both are in use, DO NOT enable termination within the controller,
because in this configuration the controller is actually in the middle of the SCSI Bus.
Š Narrow (50pin) devices SHOULD be connected part way along a wide (68pin) SCSI
bus. If you must connect such a device at the end of a wide (68pin) SCSI cable then
suitable termination must be added to achieve correct termination of the 'unused' data
lines. A terminator within the Narrow Device cannot provide this function.
9 Ensure drive is enabled to “auto start” when power is applied.
9 Disable Target Initiated Synchronous Negotiation (AKA Target Initiated Synchronous
9 Does the drive spin up and remain spinning ?
9 Does the SCSI controller recognise the drive during boot up ?
9 Check all connectors are seated correctly
9 Check that there are no bent pins
9 Try replacing the cable and terminators if possible, make use of the drives on board
9 Try low level formating the drive and verifying the data area
9 Check that the cable lengths are within the ANSI specification for the interface transfer
rate used and the number of devices installed on the bus.
9 If attached through a removable carrier, try removing the drive from the carrier and
attaching direct to the bus.
9 If running a “wide” (68 pin) device from a “wide” controller through a “narrow” bus,
try “disabling wide negotiation” in the controller.
9 Try reseting controller defaults;
Š Enable “Reset IC Initialisation”
Š Disable “plug and play” SCAM support
9 LVD devices are backwardly compatible to Single Ended controllers as long as the
system and drive(s) are configured correctly. When attaching LVD devices to Single
Ended, Wide or Narrow controllers one should consider the following:
Š LVD hard disk drives have no termination on board. This must be provided for
externally, either from another device or from a separate termination block.
Š Depending on how the controller handles the "Diff Sense" line on the interface you
may need to "Force Single Ended" on the drive, this is a jumper able option.
9 On multi-channel SCSI controllers, if using one SCSI controller, one must only use two
channels off each controller.