"Jim Michaels" <> wrote...
>I am pretty sure no x64 version of any microsoft OS runa MSDOS
>applications, but does the 32-bit version of any of the Vista family run
>MSDOS applications?
Hi Jim,
Yes: 32-bit Vista can run 16-bit MS-DOS and Windows 3.x applications. The
NTVDM is present and fully functional in 32-bit Vista.
Like any program, a specific application may encounter some compatibility
problems under Vista. Writing to file locations like anywhere under the
\Windows directory, or under \Program Files, is tightly restricted under
Vista. This may cause problems for older applications. And as always, DOS
applications which attempt to directly address the hardware will fail when
running in the NTVDM; they need to request system services by calling DOS
interrupts instead. But, these limittaions have applied since NT 3.1, so
nothing new really.
On a purely anecdotal note: I keep a copy of Visicalc 1.0 (c.1981) which I
run on every new version of DOS and Windows, as a rough-and ready
compatibility guide. I'm glad to say Visicalc opens and closes files, and
even prints, when running on Vista! I've also helped a few users get their
legacy business applications running on Vista, by setting up codepage
support etc. Basically everything works pretty much the same as before.
As you note, 16-bit applications cannot run on 64-bit Windows (whether XP,
Server 2003 or Vista). This is a limitation of the hardware - the IA-32 VDM
instructions used by Windows' NTVDM just cannot run on a 64 bit processor
when the processor is in 64 bit Mode. If the 64-bit processor is running in
32-bit mode, then the VDM instructions are available (so, you can run DOS
apps on 32-bit Vista runing on a 64-bit CPU ... since nearly all new CPUs
are 64 bit anyway).
Hope it helps!
--
Andrew McLaren
amclar (at) optusnet dot com dot au
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