    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1594          10/01/96

    TITLE:  Bravo and 3COM 3C5X9 and Adaptec 2940

    ISSUE

       When a 3COM ISA 3C509 network adapter and Adaptec AHA2940 SCSI
       PCI adapter are installed in the Bravo MS system, executing
       3COM's configuration utility may result in the following error
       condition:

        "12.03 The computer has a memory problem and needs to be
       serviced."

       This issue affects the following systems: 501749, 501772, 501774,
       501777, 501814, and 501815.

    BACKGROUND

       The 3C509B adapter is an ISA adapter that can be configured as an
       ISA or EISA adapter. Since the adapter has this capability, the
       configuration/diagnostics utility must be able to determine if
       the board is configured correctly when it is installed in a ISA
       slot.

       The error condition occurs when the utility performs a word read
       at address FC80. The Adaptec 2940 adapter has reserved that
       address location and puts up an error flag whenever an unknown
       entity comes in contact with the address. Adaptec puts up the
       flag because they want to protect the BIOS on the 2940 adapter
       from being manipulated by foreign entities. The error flag is
       passed to the computer system and the system generates a memory
       error condition.

    ACTION

       When configuring the 3COM adapter, remove the Adaptec 2940
       adapter from the system.

    NOTES

       This problem only exists when the 3COM and Adaptec adapters are
       installed in the computer at the same time, and the 3COM
       configuration utility is being executed.

       No problems exist after the 3COM adapter has been configured and
       the Adaptec adapter has been reinstalled in the computer.

    TAN 001016RC

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