[comp.os.os2.misc] Q: How to get DOS box in OS/2 V2.0 PR3

ant@brolga.cc.uq.oz.au (Anthony Murdoch) (05/15/91)

wayne@csri.toronto.edu (Wayne Hayes) writes:
>Second, one of the older Beta versions had a bug that wouldn't allow any
>DOS boxes to open if there weren't any DOS devices loaded.  If the above
>doesn't work, then try adding the line "DEVICE=C:\OS2\MDOS\ANSI.SYS"
>to your config.sys file.  Then you should be able to run DOS boxes galore.
>
I haven't ever played with OS/2, and I don't have a copy of any of the
pre-releases (I'd love to have a copy to play with), but I have been
following the conversation here with a fair amount of interest.  I have a
few questions that I would like answered if possible.

First of all, Wayne mentions above loading a DOS device in the OS/2
config.sys file.  In his example, he loads it from "C:\OS2\MSDOS" (I take
it he meant MSDOS and not MDOS).  Is this driver (in this case ansi.sys)
just an ordinary MSDOS driver or is it a special OS/2 protected version of
the MSDOS drivers.  If the former, is there an option to have OS/2
versions of these that will work inside DOS boxes.

Secondly, how much memory do you have available in a DOS box.  Intuatively
(though I know things never work that way) I would think you should be
able to have 640K or better if you are using DOS 5.  My reasoning is this;
All the usual drivers, (mouse, ansi.sys, etc) should be loaded into memory
completely separate from the 1024K allocated to the DOS box.  If you have
MSDOS loaded high, then most of it is out of the first 640 of that 1024.
Using the usual tricks, it should also be possible to reclaim some of the
641-1024 back as DOS memory (you're not going to be using EMS memory are
you ?).  I think this will all add up to over the 640.

If this is the case, then it's almost worth getting OS/2 to get DOS
working better :-)  Please be forth-comming with any comments you might
have about my stupidity (or brilliance :) as the case may be.

BTW, I was hoping to manage a similar trick with just DOS 5, and I
probably would have managed to get over 640K if it wasn't for the fact
that 32K of my high memory is taken up by a scanner card and an ethernet
card.  the best I was able to muster was 635 or there abouts.  But I
suppose that isn't too bad for a machine with VGA.

ant

-- 
  V   ant                       "It's great to be young and insane"
 \o/  ant@brolga.cc.uq.oz.au                    - Dream Team
 -O-  Anthony Murdoch           Prentice Centre
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