Power Macintosh: SCSI Problems Related to Cable Quality (5/95)


I am using a Power Macintosh without an internal hard disk. Instead, I am using external hard disks. When I connect up to two hard disks, everything works without any problems. However, when I connect three or more SCSI devices, all of the devices will not mount. Changing the SCSI ID or position in the SCSI chain does not solve the problem. I am using well made third-party SCSI cables, so I don't think cabling is the problem.

The Power Macintosh computers have a higher performance SCSI bus which is more susceptible to noise and signal integrity than other Macintosh computers.

We have found that, in most cases, after installing all Apple brand SCSI cables and an Apple brand terminator, the abnormal behavior of the external SCSI devices is reduced or eliminated.

It is strongly recommended that Apple cables or third party cables which match Apple's double shielding (wire braid and copper sheath) be used to assure maximum performance and trouble free operation.


Article Change History:
30 May 1995 - Minor typographical correction.

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Published Date: Feb 19, 2012