TITLE
    Adaptec 2940 Ultra SCSI card: Read Me
Article ID:
Created:
Modified: 		36422
12/3/97
8/24/99
TOPIC

    Power Computing provided the information in this article and it was deemed accurate as of 14 November 1997. Apple Computer, Inc. is not responsible for its content. This article is being provided as is and will not be updated in the future.

DISCUSSION

    Please do not remove the Adaptec 2940 Ultra SCSI card. The card must be installed in the top slot of the computer for correct system operation. See the computer user's guide for additional information.

    The Adaptec 2940 Ultra SCSI card is capable of supporting up to a 40 MB/sec sustained data transfer rate from the installed primary wide hard drive(s), and up to a 20 MB/sec sustained data transfer rate from the installed primary fast hard drives(s). In conjunction with Ultra SCSI or fast SCSI drives, this can significantly improve data transfer rates in certain applications.


    Available SCSI Buses (precautions on adding internal devices)

    - The PowerTower Pro G3 has three SCSI buses. The fast built-in SCSI bus is a 10 MB/sec bus used for the CD-ROM drive, other internal SCSI devices such as Zip or Jaz, and any additional hard drives. The connector for this bus is located on the main logic board and uses a separate 50-pin cable. The standard SCSI bus is a 5 MB/sec bus which is used to connect external devices through a 25-pin connector on the back of the computer.

    - The Adaptec 2940 Ultra SCSI card adds a faster third internal ultra SCSI bus which is capable of sustained data transfer rates of up to 40 MB/sec using a 68-pin cable and sustained data transfer rates of up to 20 MB/sec using a 50-pin cable which are both specifically designed and tested by Power Computing for this bus.

    - The internal SCSI cable, attached to the Adaptec 2940 Ultra SCSI bus, supports a maximum of two wide internal hard drives and/or two narrow internal hard drives.

    - Wide-to-narrow and narrow-to-wide SCSI converters are not supported.

    - Any pre-installed hard drive(s) attached to the Adaptec 2940 Ultra SCSI bus will be configured for SCSI ID 0 (and ID 1). This Adaptec 2940 Ultra SCSI bus is also compatible with most older generation SCSI 1 and SCSI 2 devices.

    - Information about SCSI termination is available in the PowerTower Pro User's Guide and the Adaptec User's Guide included with your PowerTower Pro G3.


    External SCSI Buses (precautions on adding external devices)

    - A Standard DB25 SCSI connector built into the back of the computer is connected to the 5 MB/sec internal SCSI bus. This bus can be used for other external SCSI devices such as hard drives and scanners.

    - A 68-pin wide SCSI connector is present on the Adaptec 2940 Ultra SCSI PCI card backplane. This connector provides access to the 40 MB/sec wide internal bus. Power Computing recommends connecting external SCSI devices to the external SCSI connector on the main logic board. Should you decide to connect external devices to the Adaptec 2940 Ultra SCSI card, care should be taken to ensure that SCSI termination is configured correctly, that the length for SCSI cabling is not exceeded and that only high quality SCSI cables are used; see the Adaptec User's Guide for additional information.

    - The Adaptec 2940 Ultra SCSI wide external SCSI connector will not function properly if both the internal wide and internal narrow connectors are being used.


    About PowerDomain Control

    PowerDomain Control is a utility from Adaptec, Inc. that is used to change various operating parameters on the Adaptec 2940 Ultra SCSI PCI card.

    The PowerDomain Control software should be installed in the Control Panels folder. To install the software follow these steps:

    1. Double click the System Folder icon on your hard disk to open it.
    2. Find the "Control Panels" folder and click on the "PowerDomain Control" icon and drag it onto the "Control Panels" folder icon.

    Please refer to the appropriate section of the Adaptec User's Guide for more information on the Adaptec 2940 Ultra SCSI card or the PowerDomain Control software.


    (8/25/97)

    Copyright 1997 Power Computing Corporation. All rights reserved.
    Power Computing and Power logo are trademarks of Power Computing Corporation, registered in the U.S.A. and other countries. Adaptec, the Adaptec logo, PowerDomain Control and Adaptec 2940 are trademarks of Adaptec, Inc.

Document Information
Product Area: Computers
Category: Power Computing Corp.
Sub Category: Troubleshooting

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