    AST RESEARCH, INC.            TECHNICAL BULLETIN #0890                2-9-94

                       POWER EXEC 4/XX SL GHOST RAM DETECTION

    PROBLEM:       "Ghost" RAM is reported when using QEMM versions 6.2 and 7.01
                   on the Power Exec 4/XX SL system.  QEMM does a check of the
                   CPU and, while there, leaves an image of itself.  This results
                   in a "ghost" that is detected when doing a RAM-area check
                   using utilities such as Manifest.  This ghost-image interferes
                   with some network cards being recognized when installed into
                   the Power Station.  An example is shown below:

                        Expanded/Pages
                            n=048C     Memory Area    Size Logical Page
                        0n00 U+++ 0400 - 9FFF    624K 4 - 42
                        1n00 ++++ C000 - CFFF    64K  0 - 3
                        2n00 ++++
                        3n00 ++++
                        4n00 ++++
                        5n00 ++++
                        6n00 ++++
                        7n00 ++++
                        8n00 ++++
                        9n00 ++++
                        An00 UUUA-------(Ghost RAM image)
                        Bn00 UUUU
                        Cn00 FFFF
                        Dn00 UUUU
                        En00 UUUU
                        Fn00 UUUU
                                 + = Mappable
                                 F = Page Frame
                                 U = Unmappable

    CAUSE:         The problem has been traced to code problems within QEMM 386.

    SYSTEMS
    AFFECTED:      All models of the Power Exec 4/XX SL system using QEMM
                   versions 6.2 and 7.01.

    SOLUTION:      Quarterdeck has indicated that the problem is with their code.
                   A new version (7.02) has been released and is available.