ID:VD RAMDRIVE, VDISK and QEXT.SYS
Quarterdeck Technical Note #123
by Stan Young

DESQview's QEXT.SYS driver for 286 machines with extended memory,
utilizes 64K of extended memory at the 1 Megabyte address (1024K)
for loading parts of DESQview outside of the 640K address space. 
Since this lowers the overhead of DESQview in DOS, it is
generally desirable to load this driver if you have extended
memory.

QEXT.SYS is compatible with all known versions of IBM's VDISK
utility and most versions of MS-DOS VDISK.  It is not compatible
with Microsoft's RAMDRIVE.SYS versions prior to 2.00.  Prior
versions of the RAMDRIVE utility are not compatible with IBM
VDISK or VDISK-type utilities.  Since QEXT.SYS must follow the
VDISK's conventions for loading into memory, RAMDRIVE versions
prior to 2.00 cannot be used.

It is apparent that some versions of MS-DOS VDISK are actually
Microsoft RAMDRIVE renamed.  QEXT.SYS will not work with these
either.

If you are having trouble getting QEXT and VDISK to coexist with
an MS-DOS version you believe to include a true VDISK, check to
see if the VDISK reports a version number on boot up that is
different than the version of DOS you are running.  QEXT
identifies itself by adopting the same version number as the DOS
that it is running with.  This is the IBM convention.  If your
VDISK version is different than the DOS version, QEXT may not be
identified by the VDISK you are loading.  If you think this is
happening, you might try the version of QEXT.SYS that is
currently on the DESQview Bulletin Board System.  This version
supports a parameter (/VD) that allows you to specify the VDISK
version number with which QEXT.SYS will identify itself.

If you are experiencing conflicts between QEXT.SYS, RAMDRIVE.SYS
or VDISK.SYS, the only solution is to run IBM VDISK, a compatible
version of MS-DOS VDISK, RAMDRIVE.SYS ver 2.00 or later, or a
third party RAMDISK utility such as AST's FASTDISK.  If you do
use the AST FASTDISK, be aware that you must specify when loading
it the address where it should load, since its default is to load
at 1024K (1 Meg) and if loaded there will disable QEXT.SYS. 
Consult the AST manual for loading instructions.  For expanded
memory users, Compuserve or the DESQview bulletin board contain a
Shareware program called NJRAMD.SYS that creates a RAMDISK in
expanded memory.  Many users have reported this works well for
them.

     Copyright (C) 1991 by Quarterdeck Office Systems
              * * * E N D  O F  F I L E * * *