JackHammer: Connecting External Devices

This article provides important instructions for connecting any SCSI device to the PCI Ultra SCSI JackHammer·SE (or JackHammer).
Important: These instructions are important when connecting any SCSI device to the JackHammer's external SCSI-3 PCI connector. Data transfer errors may occur if external SCSI devices are connected.

The JackHammer ships pre-installed in the Workgroup Server 9650. The Workgroup Server 9650 contains an internal 68-pin SCSI cable that connects to the JackHammer. This cable supports up to four internal devices.

Connecting even one external SCSI device to the JackHammer's external 68- pin connector extends the overall length of the SCSI bus beyond the limit for which Apple and StreamLogic can guarantee error-free operation. The combined length of the internal cable and external cables reduces the reliability of all devices connected to the JackHammer.

To connect external Ultra-3 devices to your server and guarantee error-free data transfer, do one of the following:

When choosing a SCSI card dedicated to external devices, Apple recommends selecting a differential card to ensure maximum expansion capability. The total cable length and SCSI card type (differential or single-ended) determines the total number of devices you can effectively connect together.

Published Date: Feb 18, 2012