From: rafetmad@cheshire.oxy.edu (David Giller) Subject: Re: DOS/MS Windows compatibility for Free Software Date: Mon, 8 Jun 1992 01:46:45 GMT
v206gb6c@ubvmsb.cc.buffalo.edu (PauL M SchwartZ) wrote:
>In article <3295@key.COM>, rburns@key.COM (Randy Burns) writes...
>>What is being done/thought about to allow software developed originally
>>for DOS and MS Windows to be used with free OS's.
>>
>>I have heard about a program that would allow MS DOS to to be run under
>>Linux under 8086 emulation mode.
>>
>>1) A kernel hack that would allow MS Windows 3.0 or 3.1 to run under the
>> DOS emulation mode under Linux. My understanding is that this would
>> essentially involve writing a set of DOS Protected Memory Interface
>> routines.
>
> This isn't gonna happen. There is no way to access DPMI from the virtual
>8086 mode. The emulation mode thinks it is a 8086 box all by its lonesome.
Not true actually. OS/2 2.0 provides DPMI services to multiple V86 boxes.
>MS Windows 3.0 runs OK under this in real (*yuck*) mode and 3.1 dropped this
>mode all together. Don't expect it to come back for Win 4.0. As of yet the
>Linux project is working on stabilizing the OS itself (and writing a new
>file system (I hope)). THis is far more important than getting MS-DOS to run
>under the system. The ability to run DOS programs will have a limited effect
>on most users. They haven't gone to some of the relatively well supported
>commercial *ix's that have DOS compatibility because they don't want to go to
>*ix. Additionally, as it has been sited here many times before(the gnu group)
>many commercial users want support rather than a superior system. That is a
>major road block to the acceptance of a Linux type system in a commercial
>setting. I've started to ramble, ergo, I'm outta here.
Completely agreed. Linux and others like it aren't even intended to take
over the world. Linux is a system with an intentionally limited audience:
technical users and hackers. It's a phenomenal system, there's no doubt.
However, loading it with things like DOS emulation would be a big mistake,
and could only harm the purity and efficiency of the system. If you need
to run both DOS and protected programs together, get OS/2, or if it ever
comes out with all that was promised, NT. Of course, the problem is that
such integration costs in terms of machine requirements.
There is a practical side to the problem, too. Getting a DOS emulation
that is close enough to DOS to run any program worth its salt is an
enourmous proposition: even for DRI and IBM, two large companies who
know what they are doing (one larger than the other, obviously) are kept
at it full-time to make a real DOS-compatible OS.
And there's more to it than just that: in order to get Windows running,
you would have to disassemble all of MS' proprietary and undocumented
features in MS-DOS and its add-ins. For example, there is a fuss going
on right now about MS' MSCDEX CD extensions to DOS. IBM wants to make
a MSCDEX-compatible interface for its DOS boxes under OS/2, but found that
they couldn't do so without violating MS' copyrights and patents. DRI
is now frantically working on a Windows-3.1-compatible DR-DOS, now that
Windows 3.1 doesn't work with their last-released DOS clone, due to Windows'
use (abuse?) of undocumented features.
Lest I start raving advocacy-type arguments, suffice it to say that asking
for such an undertaking is just plain foolishness: free software has the
potential to be of cutting-edge technology and as good or better than
commercial, but one thing it WON'T do is track the commercial market.
DOS is inherently commercial.
-Dave
-- David Giller, Box 134 | Q: How many Oregonians does it take to screw in a light Occidental College | bulb? A: Three. One to replace the bulb, and two to 1600 Campus Road | fend off all the Californians trying to share the Los Angeles, CA 90041 | experience. ---------------------------rafetmad@oxy.edu