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.