Adaptec USBXchange User Manual page 2

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U se r's G u i de : US B X ch a ng e 2
Introduction
This user's guide explains how to use the USBXchange to allow SCSI
devices to plug into the Universal Serial Bus (USB) port of your PC
compatible or Apple Macintosh computer.
The SCSI controller in the USBXchange allows you to connect up to
seven SCSI devices to your desktop, portable PC, or Macintosh computer.
These devices include fixed and removable drives, CD-R/W drives, DVD
drives, hard disk drives, magneto-optical (MO) drives, and most scanners.
The USBXchange provides transfer rates of up to 1.5 MBps or a
maximum sustained rate of 700 KBps.
Overview
The USBXchange is designed as an integrated adapter with a 50-pin high-
density (SCSI-2) connector. For installation, you simply connect the male
HD50 SCSI end of the USBXchange to the female HD50 SCSI connector
on your SCSI device. See Installing the USBXchange on PC Compatibles
on page 5, or Installing the USBXchange on a Macintosh on page 15 for
more information.
HD50 SCSI connector
USB connector
USBXchange
HD50 SCSI-2 Connector
The USBXchange is designed to act as a self-powered device and receives
its power from either the termination power line of attached SCSI devices
or, if not present, from the USB bus. In some cases, especially when using
unpowered USB hubs with attached SCSI devices which do not supply
SCSI termination power, the USB bus cannot supply the needed power for
the USBXchange to operate. In these cases, you may need an external DC
power source. See USBXchange Power Supply on page 13 (PC) and
USBXchange Power Supply on page 20 (Mac) for more information.