 
                       XtraDrive and QEMM


  This QEMM 7 technote is available from the following sources:

  Quarterdeck Technical Support BBS:  XTRADRV.TEC
                         CompuServe:  XTRADR.ZIP
                              Q/FAX:  #199


  Subject: Frequently asked questions about QEMM and XtraDrive.

  XtraDrive is a disk compression program published by Integrated
  Information Technology.  While this program is generally
  compatible with QEMM, some issues must be addressed.  Below are
  some of the most frequently asked questions about XtraDrive and
  QEMM.


  STEALTH ROM:

  Q:  When I try to install XtraDrive on a system that has QEMM and
  Stealth ROM running, I get the following error message:

  "Drive 1 is being controlled by a program that appropriates
  INT13.  You cannot install XtraDrive on this drive."

  What do I have to do to fix this?

  A:  Remove the Stealth ROM parameter (ST:M or ST:F) from the QEMM
  device line and try to install XtraDrive again.  You should only
  need to do this during the installation of XtraDrive.  Once
  XtraDrive is installed, you can restore the Stealth ROM
  parameter.

  Q:  So, I can use XtraDrive with QEMM's Stealth ROM parameter?

  A:  Under most circumstances, Stealth ROM works fine with
  XtraDrive, but if you are using the XtraDrive EMS cache you
  cannot use either of QEMM's Stealth ROM parameter (ST:M or ST:F.)
  The XtraDrive EMS cache accesses the disk via the page frame and
  this causes a conflict with Stealth ROM.  Normally, if a program
  accesses the disk via the page frame, QEMM's DBF=2 parameter will
  fix the problem.  This is not possible with XtraDrive.  The EMS
  cache will also cause problems with drivers such as EMSNETX.COM
  and Microsoft's MOUSE.COM using EMS.

  Q.  Are there any other possible conflicts with XtraDrive and
  QEMM's Stealth ROM parameter?

  A.  Under certain rare circumstances you may need to exclude a 4K
  region in the system ROM BIOS area.  If, after installing
  XtraDrive and QEMM with the Stealth ROM parameter, you get an
  Exception 13 or lockup you should refer to Technical Bulletin
  #205, STEALTH.TEC.  (This technote is installed in your
  QEMM\TECHNOTE directory when you install QEMM version 7.0)  This
  technote will help you determine which area must be excluded.
  Keep in mind, however, that the need to exclude the 4k block of
  High RAM is very rare.


  EXCLUDES:

  Q:  When I install QEMM on a system that has XtraDrive currently
  installed, I get a lockup or Exception 13 when I reboot the
  machine, loading QEMM.  What do I have to do to allow me to boot
  the system?

  A:  Simply reboot the machine and when it beeps after checking
  the memory, hold down the ALT key until prompted to press ESC to
  unload QEMM.  (If you are using QEMM's DOS-UP, you will first be
  prompted to press ESC to unload DOSDATA.)  Once you have unloaded
  DOSDATA and/or QEMM, load your CONFIG.SYS file into a text editor.
  If you have MS-DOS 5 or MS-DOS 6, you may load the DOS Editor, by
  typing EDIT C:\CONFIG.SYS and <ENTER>.  At the end of the QEMM
  device line, place the following parameter:  X=9000-9FFF.

  A sample QEMM device line would then read as follows:

        DEVICE=C:\QEMM\QEMM386.SYS RAM ST:M X=9000-9FFF

  After adding the parameter, simply save the CONFIG.SYS file and
  reboot your machine.

  Q:  When I installed XtraDrive after QEMM, XtraDrive placed an
  exclusion from 8000-A000 on the QEMM device line.  Do I need this
  exclusion and will it take away any memory from my system?

  A:  Given the way that XtraDrive is currently designed, an
  exclusion is needed.  If you are using DESQview or DESQview/X,
  the exclusion will tell QEMM to not map memory into that area, so
  the amount of memory available to each DESQview window will be
  smaller. There are a couple of things you can do to increase your
  window size if you are using DESQview or DESQview/X:

  1.  The default exclude is 8000-A000, a 128K block.  Our testing
  has determined that usually an exclusion of 9000-9FFF will be
  sufficient. This will decrease your window size by only 64K.  If
  you are using the CONVENTIONAL MEMORY disk cache, and have
  selected more than two 16K blocks of conventional memory, you
  will need to change the exclude back to 8000-9FFF.

                                OR

  2.  Load the XtraDrive driver BEFORE QEMM and take the exclude
  off the QEMM device line.  This should decrease your window size
  by only about 46K. Once again, if you are using the CONVENTIONAL
  MEMORY disk cache, your driver size will increase with each 16K
  block you add.  The default is one 16K block. If you select two
  blocks, your driver will be 66K.  If you select three it will be
  82K.  The maximum, four 16K blocks will result in a 98K driver.
  Your DESQview and DESQview/X window sizes will decrease
  accordingly.


  BUS-MASTERING:

  Q:  If I have a SCSI bus-mastering controller, can I load the
  XtraDrive device driver into High Ram?

  A:  No.  Even with double buffering, on a system with a SCSI bus-
  mastering device you will not be able to load XtraDrive into High
  Ram.  This is NOT a memory manager issue, but a limitation of
  XtraDrive.

  *****************************************************************
          Trademarks are the property of their respective owners.
  This technical note may be copied and distributed freely as long
  as it is distributed in its entirety and it is not distributed
  for profit.  Copyright (C) 1993 by Quarterdeck Office Systems
  ****************** E N D  O F   F I L E *************************