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    AST RESEARCH, INC.         TECHNICAL BULLETIN # 1157                4-26-95

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    		 ASSIGNING A BOOTABLE SCSI CONTROLLER IN A MULTIPLE SCSI
    					   CONTROLLER ENVIRONMENT

    PROBLEM

    When installing a DPT PM3224 SCSI controller on Manhattan P & V servers
    with the onboard NCR SCSI controller(s) enabled, the primary/bootable
    controller will be the DPT controller.

    CAUSE

    PCI 2.0 specifies that the BIOSes load in order, beginning with the largest
    BIOS and ending with the smallest BIOS.

    For instance, if the onboard NCR SCSI controller BIOS uses an address space
    of 16KB, and an add-in SCSI controller BIOS uses an address space of 32KB,
    the add-in controller will become the primary/bootable controller.

    SYSTEMS AFFECTED
    AST PART NUMBER AND DESCRIPTION

    All Manhattan P and V systems.

    SOLUTION

    Currently, the Manhattan P & V systems DO NOT support the option of
    allowing the user to manipulate the default settings for Primary and Secondary
    controller assignments.

    AST is currently negotiating with vendors for a BIOS that supports the PCI 2.1
    specification which allows the user to manipulate the load order of BIOSes.