OSDARVMB - RUNNING REAL DOS UNDER OS/2 (CREATING A VIRTUAL MACHINE BOOT)
07/11/96

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      Running Real DOS Under OS/2 (Creating a Virtual Machine Boot)
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Please Read Entire Document for Full Explanation of Procedures
--------------------------------------------------------------


DESCRIPTION

Some older DOS applications fail to run under OS/2's DOS emulation. 
Errors appear such as "Buffers are currently set to 0, this program 
needs 30 or more", even when buffers there are enough; or "Out of memory
" or "Incorrect DOS version", even when DOS settings have been adjusted 
to correct such errors. 

Often these errors occur because the applications are using 
undocumented DOS function calls that are not supported by OS/2's DOS 
emulator.

RESOLUTION

OS/2 has the ability to actually run real DOS in a special DOS session 
called a Virtual Machine Boot (VMB). Once set up, a VMB will function 
as a standard DOS session. 

This document discusses limitations of the different methods used to 
create a VMB. It explains the purpose of the different device drivers 
and TSRs that are used, and the differences between a VMB and a 
standard DOS session. It includes step-by-step instructions for 
creating a VMB.

Notes: 1. Make sure you have a backup of any file you intend to change.
       2. This document describes the procedure to create a VMB using 
          DOS version 6.0 or higher.

Methods Used to Create a VMB
----------------------------

Method A 
---------
Changing to the A: drive in a VMB created by Method A gives you the 
image file. If you do a dir while on drive A you will see all the files 
that were on the original diskette that the VMB was
created from. The CONFIG.SYS and AUTOEXEC.BAT used by the VMB are
on this A drive and can be edited to change the behavior of the
VMB. The A diskette can be accessed as another drive letter. (M is used 
by default in these instructions.)  

Method B: 
---------
Changing to the A drive will give you the actual diskette drive.
However, it makes it more difficult to change the CONFIG.SYS and
AUTOEXEC.BAT of the VMB once it's created. To edit the CONFIG.SYS and 
AUTOEXEC.BAT with this method, the VMB.BAT must be renamed
before the VMB is started. You can then start the VMB and change to the 
A drive to edit the files. 

Method C: 
---------
This method requires Boot Manager, and uses DOS from the C drive. A VMB 
created by this method will function like a standard DOS session, 
except for the differences noted below.
    
Differences from Standard DOS Sessions
--------------------------------------
1. The EXIT command will not work from a VMB. There is a program
   in the \OS2\MDOS directory called EXIT_VDM, that can be run
   instead to exit a VMB from the command line.
 
 2. The following DOS settings will not affect VMBs:
      
    DOS_FILES
    DOS_HIGH
    DOS_UMB
    DOS_AUTOEXEC
    DOS_DEVICE
    DOS_LAST_DRIVE
    DOS_SHELL

    All of these settings must be changed in the CONFIG.SYS of 
    the VMB.

Creating a DOS Startup Diskette
-------------------------------

Both Method A and B require a DOS startup diskette. This section is 
include for users who are unfamiliar with the process of creating a DOS 
startup diskette.
  
Note: If you already have a DOS startup diskette, it is
       best to start up with that diskette and then create
       another one from it. During the process of creating
       a VMB, the diskette will be modified. You should
       not modify an emergency DOS startup diskette.

      DOS startup diskettes can only be created from a
       real DOS system.

Creating a DOS Startup Diskette from a Native DOS System
--------------------------------------------------------
1. Start the computer.
2. Insert a blank formatted diskette in drive A.
3. At the command prompt of the DOS root directory, type SYS A:
   and press Enter.

COMMAND.COM is now on the diskette.

Creating a DOS Startup Diskette from Another DOS Startup Diskette

1. Insert a DOS startup diskette in drive A that includes the
   FORMAT.COM file from native DOS.

2. Turn on the computer, or press Ctrl+Alt+Del if it is already
   on.

3. Type FORMAT A: /S and press Enter. When you see the "Press
   any key" message, insert a blank diskette for the VMB in drive
   A, and press Enter.

COMMAND.COM is now on this diskette.

Creating a VMB From a DOS Startup Diskette, Method A
-----------------------------------------------------
You can read and write to a drive other than drive A; for
example, drive M. You can change the AUTOEXEC.BAT and CONFIG.SYS
files, and add files directly to the VMB image file on the hard
disk.

 1. Start the system to the OS/2 Desktop.
 2. Insert the DOS startup diskette in drive A.
 3. Open the OS/2 System folder.
 4. Open the Command Prompts folder.
 5. Double-click on the OS/2 Window icon.
 6. Type the following commands and press Enter after each:

      cd \os2\mdos
     copy ansi.sys a:
     copy fsfilter.sys a:
     copy fsaccess.exe a:
     copy emm386.sys a:
     copy himem.sys a:
     copy lptdd.sys a:
     copy mouse.com a:
     a:
     e config.sys

    This copies the needed files to the DOS diskette, switches
    to the A drive, and opens the VMB's CONFIG.SYS file in the
    editor.

 7. Edit the CONFIG.SYS file (it could be blank) so that it 
    contains only the following lines:

      DEVICE=HIMEM.SYS
      DEVICE=EMM386.SYS
      DOS=HIGH,UMB
      DEVICE=FSFILTER.SYS
      DEVICE=ANSI.SYS
      DEVICE=LPTDD.SYS
      FILES=40
      BUFFERS=30
      LASTDRIVE=Z   

 8. Click on File; then Save.
 9. Click on Type.
10. Select Plain Text; then click on Set.
11. Click on File; then Open.
12. In the Open filename: box, type AUTOEXEC.BAT.
13. Click on Open.
14. You are now in the VMB's AUTOEXEC.BAT. Edit the file so
    that it contains the following lines:

      ECHO OFF
     PROMPT $P$G
     MOUSE.COM
     PATH C:\;C:\VMB
     FSACCESS M=A
     C:
     CD\VMB

    Note: The M represents the drive you want to
           access the A drive as. With this method,
           changing to the A drive will always
           give you the image file, so FSACCESS is
           used to give the diskette drive another
           letter.

15. Click on File; then Save.
16. Click on Type.
17. Select Plain Text; then click on Set.
18. Close the editor by double-clicking on the upper-right
    corner.
19. You are now back at the command line. Type the following,
    pressing Enter after each:

      X:
      mkdir VMB
      cd \VMB
      VMDISK A: DOS.IMG

    Note: The X: represents the drive you want
           the VMB files stored on. The files can
           require as much as 1.44 MB.

    This will create the directory for the image file and the
    image file itself.

20. Remove the diskette from drive A.
21. Type EXIT at the command line.
22. Create a VMB Desktop icon to launch the VMB, following the
    instructions in the section "Creating a VMB Desktop Icon
    for Method A or B."

Creating a VMB From a DOS Startup Diskette, Method B.
-----------------------------------------------------
You can read or write to drive A, but you cannot change the
AUTOEXEC.BAT or CONFIG.SYS file, or add files directly to the
VMB image file on the hard disk.

 1. Start the system to the OS/2 Desktop.
 2. Insert the DOS startup diskette into drive A.
 3. Open the OS/2 System folder.
 4. Open the Command Prompts folder.
 5. Double-click on the OS/2 Window icon.
 6. Type the following commands, pressing Enter after each:

      cd \os2\mdos
      copy ansi.sys a:
      copy fsfilter.sys a:
      copy fsaccess.exe a:
      copy emm386.sys a:
      copy himem.sys a:
      copy lptdd.sys a:
      copy mouse.com a:
      a:
      e config.sys

    This copies the needed files to the DOS diskette, switches
    to the A drive, and opens the VMB's CONFIG.SYS file in the
    editor.

 7. Edit the CONFIG.SYS file (it might be blank) so that it
    contains only the following lines.

      DEVICE=HIMEM.SYS
      DEVICE=EMM386.SYS
      DOS=HIGH,UMB
      DEVICE=FSFILTER.SYS
      DEVICE=ANSI.SYS
      DEVICE=LPTDD.SYS
      FILES=40
      BUFFERS=30
      LASTDRIVE=Z   

 8. Click on File; then Save.
 9. Click on Type.
10. Select Plain Text; then click on Set.
11. Click on File; then Open.
12. In the Open filename: box, type AUTOEXEC.BAT.
13. Click on Open.
14. You are now in the VMB's AUTOEXEC.BAT file. Edit the file so
    that it contains the following lines:

      ECHO OFF
      PROMPT $P$G
      SET COMSPEC=C:\VMB\COMMAND.COM
      MOUSE.COM
      PATH C:\;C:\VMB
      C:
      CD\VMB
      VMB.BAT

15. Click on File; then Save.
16. Click on Type.
17. Select Plain Text; then click on Set.
18. Close the editor by double-clicking on the upper-right
    corner.
19. At the command line. Type the following commands, pressing
    Enter after each:

      X:
      mkdir VMB
      cd \VMB
      copy a:\command.com
      e VMB.BAT    

     Note: The X: represents the drive you want
           the VMB files stored on. The files can
           require as much as 1.44 MB.
     
    This switches to your hard drive, creates a directory for
    the VMB files, copies COMMAND.COM to that directory, creates
    a file called VMB.BAT, and opens it in the editor.

20. Edit the VMB.BAT file by adding the following lines:

      C:\OS2\MDOS\FSACCESS A:
      CD\

21. Click on File; then Save.
22. Click on Type.
23. Select Plain Text; then click on Set.
24. Close the editor by double-clicking on the upper-right
    corner.
25. At the command line, type the following and press Enter:
    
      VMDISK A: DOS.IMG

    This creates the image file on the hard drive. 

26. Remove the diskette from drive A.
27. Type EXIT at the command line.
28. Create a VMB Desktop icon to launch the VMB, following the
    instructions in the section "Creating a VMB Desktop Icon
    for Method A or B."

Creating a VMB Desktop Icon for Method A or B
----------------------------------------------
 1. Move the mouse pointer to the DOS Full Screen icon.
    Press and hold Ctrl+MB2 (mouse button 2) and drag the
    icon to the Desktop; then release Ctrl+MB2.

 2. Single click on newly created icon with the right mouse
    button. This will display its pop-up menu.

 3. Select Settings to open the Settings notebook.

 4. Select Session.

 5. Select DOS Settings.

 6. Select OK to select all DOS settings.

 7. Find and highlight DOS_STARTUP_DRIVE.

 8. Change the value box to X:\VMB\DOS.IMG. Where X is the
    drive you put the VMB directory on.

 9. Select Save.

10. Select General and change the Title field to VMB or the
    name you want to call your Desktop icon.

11. Close the window.

Multi-Start VMB General Guidelines, Method C
--------------------------------------------

Creating Multi-Start VMB CONFIG.SYS and AUTOEXEC.BAT Files
----------------------------------------------------------
The multi-start VMB is for systems with the Boot Manager setup:
DOS Version 6.0 or later in the C partition and OS/2 in a
different partition.

Create the following AUTOEXEC.BAT and CONFIG.SYS files in the
root directory of the C (DOS) partition.

Note: Use a text editor to create the files.

Replace the < > symbols around "Menu," "Normal," and "OS2" with 
brackets [ ]. These characters are misinterpreted because of the way 
the files are stored on the IBM LAN.

Note: Use the following instructions to create the VMB.
      Make sure it is running before you add other files,
      drivers, and statements for your specific 
      applications, networks, and so on.

AUTOEXEC.BAT File:

   @ECHO OFF
   PROMPT $p$g
   GOTO %CONFIG%

   :NORMAL
   C:\DOS\SMARTDRV.EXE
   PATH C:\DOS
   SET TEMP=C:\DOS
   LH C:\DOS\MOUSE.COM
   LH C:\DOS\DOSKEY
   GOTO END

   :OS2
   SET COMSPEC=C:\DOS\COMMAND.COM
   PATH C:\;C:\DOS;
   LH DOSKEY
   LH D:\OS2\MDOS\MOUSE.COM
   GOTO END
   :END

 CONFIG.SYS File:

   <MENU>
   MENUITEM=OS2,BOOT FOR OS/2 VMB
   MENUITEM=NORMAL,BOOT FOR NATIVE DOS

   <NORMAL>
   DEVICE=C:\DOS\HIMEM.SYS
   DEVICE=C:\DOS\EMM386.EXE NOEMS
   DOS=HIGH,UMB
   FILES=30
   BUFFERS=15
   SHELL=C:\DOS\COMMAND.COM C:\DOS\  /P
   DEVICEHIGH=C:\DOS\ANSI.SYS
   STACKS=9,256

   <OS2>
   DEVICE=D:\OS2\MDOS\FSFILTER.SYS
   DEVICE=D:\OS2\MDOS\HIMEM.SYS
   DEVICE=D:\OS2\MDOS\EMM386.SYS
   DEVICEHIGH=D:\OS2\MDOS\ANSI.SYS
   DEVICEHIGH=D:\OS2\MDOS\LPTDD.SYS
   DOS=HIGH,UMB
   FILES=30
   BUFFERS=20
   SHELL=C:\DOS\COMMAND.COM C:\DOS /P

Creating a VMB Desktop Icon for Method C
-----------------------------------------
 1. Open the OS/2 System folder.

 2. Select Command Prompts.

 3. Move the mouse pointer to the DOS Full Screen icon. Press 
    and hold Ctrl+MB2 (mouse button 2) and drag the icon to the
    Desktop; then release Ctrl+MB2.

 4. Close Command Prompts and OS/2 System.

 5. Change the DOS settings for the VMB icon:

    a. Select the icon created above.
    b. Press mouse button 2 to display the menu.
    c. Select Settings to open the Settings notebook.
    d. Select Session.
    e. Select DOS Settings.
    f. Change the following settings:

         DOS_UMB             to: ON
         DOS_HIGH            to: ON
         DOS_STARTUP_DRIVE  to: C:\
         XMS_MEMORY_LIMIT   to: (default is 2048--minimum)

    g. Use the following settings for applications that use DOS 
       Protected Mode Interface (DPMI):

         DPMI_MEMORY_LIMIT  to: 4 (Minimum requirement)
         DPMI_DOS_API        to: ENABLE

    Note: Do not do change any other setting until
          the VMB is running.

 6. Select Save.

 7. Select General and change the Title field to VMB or the
    name you want to call your Desktop icon.

 8. Close the window.

 9. Select the new DOS VMB Desktop icon. The following appears:

       PC-DOS 6.3 Startup Menu
          1.  BOOT FOR OS/2 VMB     (highlighted)
          2.  BOOT FOR NATIVE DOS

10. Select 1.

    Note: If you select 2, you receive an error message.
          This selection is for starting native DOS from
          the Boot Manager partition.

11. To exit the VMB, create the batch file, X.BAT (containing
    the following line), in the C:\ directory:

      @ECHO OFF D:\OS2\MDOS\EXIT_VDM

12. Type X at the command prompt.

______________________________________________________________________
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