    =

    AST RESEARCH, INC.         TECHNICAL BULLETIN # 0871B                4-4-95

    =

    			   AST COMPUTERS BANYAN ICA PLUS & BANYAN VINES

    PROBLEM

    When 16 megabytes (or more) of memory is installed in an AST computer system,
    a Banyan Vines ICA Plus adapter card is not functional.

    CAUSE

    The Banyan Vines ICA Plus adapter card requires 128k of contiguous memory
    space to be mapped out of system memory for each adapter installed.  If two
    adapter cards are installed in a computer, the mapping for the first card
    usually takes place in 512k-640k region and the mapping for the second card
    usually takes place in the 15-16 megabyte memory region.  If RAM is installed
    in the 15-16 megabyte region, a conflict will exist between RAM and the ICA
    Plus adapter card.

    BACKGROUND

    This problem is usually experienced when a computer system containing two ICA
    Plus adapter cards and 8 megabytes of RAM has been operating without any
    problems.  Then the owner of the computer system decides to increase the
    amount of RAM to 16 megabytes.  Once the computer contains 16 megabytes of
    RAM, a conflict will exist and a adapter card will loose its functionality.

    NOTE

    The ability to set 512K of base memory is not available in the Manhattan P or
    V systems, but it is available in the older systems: Premium SE, Premium TE,
    Premmia SE, and SMP.

    SYSTEMS AFFECTED

    All AST computer systems except Manhattan SMP.

    SOLUTION

    Several possible solutions exist to resolve this problem.

    1.  Use less than 16 megabytes of memory.  AST has successfully tested the
    configuration with 8 megabytes of memory.

    2.  Disable the 15th megabyte region of memory.  This is a advanced setup
    feature and currently is only supported on AST's Manhattan SMP computer.

    3.  Use Banyan's Memory Reduced ICA adapter card.  The ICA-RM adapter card
    only requires 16k of contiguous memory space to be mapped out of system memory
    for each adapter installed.  Additionally, the card can be mapped anywhere in
    the Shared Memory Region (640k-1MB).  Support for the Memory Reduced ICA
    adapter card began with release 5.54(5) of the Banyan Vines operating system.
    Banyan Product Notice 430 provides details on the ICA-RM adapter card.