Date: Fri, 2 Dec 1994 11:02:18 +0900
From: Stephen Turnbull <turnbull AT shako DOT sk DOT tsukuba DOT ac DOT jp>
To: aferrign AT iisst3 DOT italy DOT NCR DOT COM
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: DeskView/X

   From: Angelo Ferrigno <aferrign AT iisst3 DOT italy DOT NCR DOT COM>

   I'd like to purchase a copy of DV/X for my PC at home. Two questions:
   1) Is latest release of DV/X (I think it's Rel. 2.x) compatible with
   DJGPP 1.12 (I have heard they use a cheated version of go32, I don't know
   which release). Any known problems or caveats?

None that aren't general problems with v 1.12 to my knowledge.  I have
compiled multiple versions of Ghostscript (217 object, 7 libraries
involved in the most recent one) with it.  The ld 2.4 "too many
objects" bug can be worked around by using GO32 v1.11 via stubedit.
This is not DV/X-specific however; it occurs under straight DOS as well.

DV/X does not use GO32, they use a different extender.  They also use
their own VM mechanism.  This does not affect properly running
programs.  However, it means that if a GO32 program crashes it is more
likely to bring down the whole system.  Often it doesn't, so this is a
big win over plain DOS.  Repeat: DV/X plus QEMM can often save what
would otherwise be a system hang requiring a hard reset.  Exception +
traceback crashes never cause a problem in my experience.

I have compiled a lot of X and Motif programs no problem with v1.12.

   2) Will DJGPP V2.0 be compatible with DV/X?

Yes and maybe no.  You can use QDPMI.  This should not have the
problems that QDPMI gives GO32.  But it means that v2.0 will not be
much of an improvement real-mode RAM-wise over v1.1x, since QDPMI uses
about 100KB of buffers per invocation (that's a guess, I *know* it's
big).  CWSDPMI cannot be used *before* DV/X, as QDPMI uses proprietary
extensions to DPMI 0.9 to communicate with DV/X.  Charles Sandmann
wants CWSDPMI to run in a DV/X window , but it doesn't do so reliably
yet.  I have successfully run v1.12-compiled X programs with GO32 and
CWSDPMI---but not twice in the same window.  I have not yet tried a
v2.0-compiled executable, as I don't have a v2.0 compiler/linker/libc.

In general, I can recommend DV/X as a wonderful thing if you must work
in a DOS/Windwoes environment, although it cannot deal with enhanced
mode Windows programs.  But the system demanded by DOS+DV/X+Windwoes
can easily handle Linux (except that DV/X excludes most Unix
functionality, so a full blown DV/X system has a 25MB HDD footprint,
while a minimal Linux + X system demands about 70MB on your HDD).
So....  You pays your money (ouch) and makes your choice.

Hope this helps.
    --Steve