FYI

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          TITLE: Configuring LOADER.COM for Multiple OS boots
   DOCUMENT ID#: FYI-M-1909
           DATE: 07-15-92
        PRODUCT: DR MULTIUSER DOS
PRODUCT VERSION: 5.x
     SUPERSEDES: 

ISSUE:
The following information is intended for advanced DOS users and
support is not available to endusers from normal support channels.
Because the use of LOADER changes the Master Boot Record it is
recommended that full backups of all partitions on the first
physical drive be made. Novell is not responsible for any loss of
data.

SUBJECT:
Utilizing the LOADER.COM that was supplied with Multiuser DOS,
permits users the ability to load several operating systems on a
computer and allow a user to choose which operating system to boot
into. This is can be a very effective tool when users need to test
various operating systems.

If MS-DOS 5.0 is to be one of the operating systems utilized then
it needs to be installed on the computer first. Other operating
systems such as OS/2, DR Multiuser DOS and DR DOS can then be
installed. DR DOS 6.0 is especially flexible in a multiple OS
environment as it will first look for a file called DCONFIG.SYS
before trying to locate CONFIG.SYS. This allows 2 separate DOS
based OS's to reside on the same disk and use different
configuration files.

Changing the names of the config and batch files will mean that the
DR DOS Setup utility can no longer be used. All adustments will
need to be done manually.

The SHELL line in DR DOS's DCONFIG.SYS file allows users to point
DR DOS to a batch file other than AUTOEXEC.BAT.  An example of this
would be: 

SHELL=C:\DRDOS\COMMAND.COM C:\DRDOS /P:DRAUTO.BAT /E:512

The parameter /P:[filename] instructs the shell to use the named
file as a replacement to AUTOEXEC.BAT. DRDOS would then boot using
the DCONFIG.SYS file and the DRAUTO.BAT file. MS-DOS would boot
using the CONFIG.SYS and AUTOEXEC.BAT files thereby permitting the
two systems to use separate configurations. Also note in the above
example that COMMAND.COM is being loaded from the DRDOS directory.
This is to prevent accidentally loading the wrong command
processor. In fact, it is recommended that no command processor be
located in the root. Most user Paths contain the root directory and
this can cause system halts by loading the wrong command processor.

In order to use LOADER to boot between multiple operating systems,
it is necessary to create a boot list file. Generally, this file is
just called BOOTLIST.TXT, however it can be named using any valid
DOS filename. At this time there is no specific designation for MS-
DOS 5.0 so it can only be the default operating system.

The bootlist is an ASCII file, which must reside in the root
directory of the primary DOS partition and contains a list of the
available operating systems. The boot list can contain up to 20
lines. Each line should have the following format:

FILENAME.EXT TYPE [[NUM]] [COMMENT]

Where FILENAME.EXT is the complete name of the operating system
kernel file that is first loaded. For example, the DR DOS 6
filespec would be IBMBIO.COM. Type identifies the nature of the
operating system. For type enter one of the following single-
character codes:

     C = Concurrent DOS
     M = Multiuser DOS with or without secured fixed-disks
     D = DR DOS
     P = CP/M
     O = OS/2
     S = DR DOS with or without secured fixed-disks
     F = FlexOS
     B = Binary file
     3 = MS/PC DOS prior to Ver 3.3

example of a Bootlist:

CCPM.SYS    C    Concurrent DOS 3.0
DRMDOS.SYS  M    [5] Multiuser DOS
IBMBIO.COM  D    DR DOS 6.0

The [num] parameter is optional and sets a timeout for that
operating system (only one timeout can be used). If a user wanted
DR Multiuser DOS to load automatically after 5 seconds put [5]
after the TYPE on that line. The timed OS will load in 5 seconds if
no other selection is made. 

The [comment] parameter is also optional and you can use that to
identify within the bootlist file what operating system will be
loaded. Any other comments needed can also appear on the screen
when the machine is rebooted.

Once the bootlist file is created, LOADER must be run from the
command line, accompanied by the bootlist parameter. 

LOADER BOOTLIST.TXT

LOADER is not DOS version sensitive but it is recommended that it
be run from either DR Multiuser DOS or DR DOS. Once LOADER is run
it will, on the next reboot of the computer, display the bootlist
accompanied by a selection of function keys. Select the OS to boot
by striking the appropriate function key. The F1 key is always
reserved for the Default OS. 

If a timeout value is required for the Default OS a slightly
different procedure needs to be run. Since the Default OS is not in
the bootlist the timeout value is given when LOADER is run: 

LOADER BOOTLIST.TXT [15]

The above line will give the Default OS (such as MS-DOS 5) a 15
second timeout.

To remove loader from a system use the command line:

LOADER /U

IMPORTANT                    IMPORTANT                  IMPORTANT
***************************************************************** 
LOADER has three hidden system files: LOADER.SAV, LOADER.SYS and
IBMBIO.LDR. These files are position sensitive and cannot be moved
or deleted except by LOADER.COM. It is not possible to remove
LOADER from a system by deleting these files. In fact, it is not
possible to remove LOADER from a system except by using LOADER.COM
or a low-level format. The file LOADER.SAV is an exact duplicate of
the Master Boot Record before LOADER was installed. Moving or
deleting this file will mean that the system cannot be restored to
its previous state. If the files are removed LOADER will give an
error indicating "Bad or missing IBMBIO.LDR" on bootup. LOADER will
then allow the default OS to be loaded by striking any key. No
other OS will be able to boot.

The Superstor Disk Compression utility that comes with DR DOS is
not compatible with other operating systems including DR Multiuser
DOS. If an enduser has used the DR DOS Superstor utility to
compress the drive then it is advised that the user not load the
drivers SSTORDRV.SYS or DEVSWAP.COM with other operating systems.
The compressed data will not be accessable.
*****************************************************************