On Friday, 97/04/18, Stephen Haffly wrote to David Noon about
"Dedicated Dos" as follows:
SH>  DN> I use this approach for both PC-DOS 6.3 and PC-DOS 7.0 sessions run
SH>  DN> from image files on a HPFS partition. These sessions can access all
[snip]
SH> Even if he doesn't, I do.  Please post the details.
Hi Stephen,
Creating a specific DOS image is quite simple, except that you need a
bootable copy of the DOS release to start the process. The best floppy
disks to use are 720KB ones, or even 360KB, since the image file is as
large as the floppy, even if most of the floppy is free space.
1) Boot a copy of "DOS X" and format a floppy disk with the /S option.
2) Boot your OS/2 system.
3) From your x:\OS2\MDOS directory, copy EMM386.SYS, HIMEM.SYS,
FSFILTER.SYS and FSACCESS.EXE to the root directory of the floppy
disk.
4) Create a CONFIG.SYS file in the root of the floppy with the
following (as a minimum):
   DOS=HIGH,UMB
   DEVICE=A:\HIMEM.SYS
   DEVICE=A:\EMM386.SYS
   DEVICEHIGH=A:\FSFILTER.SYS
   DEVICEHIGH=x:\OS2\MDOS\ANSI.SYS  [Only if you want ANSI screen stuff]
5) Create an AUTOEXEC.BAT in the root of the floppy with the following
(as a minimum):
   VERIFY OFF
   PATH A:\;x:\OS2\MDOS;x:\OS2
   LH APPEND x:\OS2\MDOS;x:\OS2
   LH DOSKEY EXIT=EXIT_VDM $*
In both the CONFIG.SYS and the AUTOEXEC.BAT, the A: drive letter
should be coded exactly as above, even if the FDD you are using for it
is actually B:. This is because the image file will always be A: at
run time.
6) [Optional, as testing always is] Test the floppy image using the
"DOS from A:" icon in the Command Prompts folder, inside your OS/2
System folder. If your FDD is B: you will need to fiddle with the
session's settings notebook to make it boot its A: image from physical
B:, but that's fairly easy: adjust the DOS_STARTUP_DRIVE setting. Fix
any problems; that's not always easy.
7) When finished testing, create an image file by running VMDISK a:
z:\dosdir\dosboot.vmb, where the first parameter is the FDD from which
to read the bootable diskette and the second parameter is any valid
path/filename
8) Drag an drop a program template from the system templates folder.
Give it a program name of *, a working directory of wherever you left
the image file from step #7, and a session type of DOS Full-screen or
DOS Windowed. Set the DOS_STARTUP_DRIVE to the path/filename of the
image file. Adjust the memory settings for XMS, EMS and/or DPMI, as
needed.
Thereafter, you just double click on the icon created in step #8
whenever you want that specific version of DOS.
The main "gotchas" are:
EMM386.SYS doesn't like it when you set the EMS_MEMORY_LIMIT to zero.
REM the DEVICE line out of CONFIG.SYS too, to swith off EMS.
You cannot readily access the real A: drive from the VMB session. You
can use FSACCESS to assign it a later letter, such as FSACCESS K=A,
which will make it the K: drive in the VMB. Unfortunately, COMMAND.COM
doesn't always pick up dynamically added drives, so you sometimes need
to run DOSSHELL or the like after the FSACCESS to access the FDD.
Regards
Dave

 * KWQ/2 1.2i * Darwin stubby -- truly the survival of the fittest.
--- Maximus/2 3.01
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