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   Microsoft Product Support Services Application Note (Text File)
       PD0461: HOW DO I OPTIMIZE MY USE OF UPPER MEMORY BLOCKS?
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                                                   Revision Date: 9/91
                                                      No Disk Included

The following information applies to Microsoft MS-DOS 5 Upgrade.

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You have set up your computer to load programs or device drivers into
upper memory blocks (UMBs). Now you want to make sure you are making
optimal use of those UMBs, so you can run as many programs in the
upper memory area as possible.

This document provides techniques for making the best use of your
computer's upper memory area. To use these techniques, you should be
familiar with the information on pages 313-330 of the "Microsoft MS-
DOS User's Guide and Reference," which explains how to load programs
into UMBs. In particular, pages 327 and 329 provide some basic
information about optimizing your use of UMBs.

This document explains the following optimization techniques:

 - Starting EMM386 with the NOEMS switch instead of the RAM switch

 - Finding the best order for loading drivers and programs into UMBs

 - Adjusting EMM386 to provide more UMBs


STARTING EMM386 WITH THE NOEMS SWITCH INSTEAD OF THE RAM SWITCH
===============================================================

If you do not use programs that require expanded memory (EMS), start
EMM386 with the NOEMS switch. Doing so can give you an additional 64K
of UMBs, because the NOEMS switch instructs EMM386 not to create an
EMS page frame in the upper memory area. If you start EMM386 with the
NOEMS switch, programs will be unable to use expanded memory, even
when they are running with Windows.

To start EMM386 with the NOEMS switch:

1. Edit your CONFIG.SYS file. To edit the file using MS-DOS Editor,
   type the following at the command prompt:

      edit c:\config.sys

2. Find the DEVICE command that starts EMM386. If the DEVICE command
   contains the RAM switch, change it so it contains the NOEMS switch
   instead. The DEVICE command for EMM386 should now look like the
   following:

      device=c:\dos\emm386.exe noems

3. Save the changes (if any) to your CONFIG.SYS file and quit the text
   editor. If you are using MS-DOS Editor, choose Exit from the File
   menu. When MS-DOS Editor displays a dialog box prompting you to
   save your file, choose Yes, or press ENTER.

4. Restart your system by pressing CTRL+ALT+DELETE.

After you complete this procedure, some programs might display out-of-
memory messages or fail to run. Such programs might require expanded
memory. If this is the case, replace the NOEMS switch with the RAM
switch to make expanded memory available again.


FINDING THE BEST ORDER FOR LOADING DRIVERS AND PROGRAMS INTO UMBS
=================================================================

When you start a program using the DEVICEHIGH or LOADHIGH commands,
MS-DOS loads that program into the largest remaining UMB, even if it
would fit into a smaller UMB.  Because of this, the order in which you
load programs into UMBs is important when trying to optimize your use
of the upper memory area. You will need to experiment to find the best
order for your system.

Creating a Startup Disk
-----------------------

Before you start optimizing, create a startup floppy disk that
contains a backup copy of your CONFIG.SYS and AUTOEXEC.BAT files. To
do so, insert a formatted floppy disk into drive A and type the
following commands:

   sys c: a:
   copy c:\config.sys a:\
   copy c:\autoexec.bat a:\

Having this startup disk will enable you to experiment more freely; if
you change your CONFIG.SYS or AUTOEXEC.BAT file, and your computer
locks up when you restart it, just insert the backup disk in drive A
and press CTRL+ALT+DELETE.

Finding the Best Load Order
---------------------------

When loading programs high, MS-DOS loads each program into the largest
remaining UMB, even if it would fit into a smaller UMB.  Therefore,
the order in which you load programs into UMBs is important. In
general, when loading programs into the upper memory area, load larger
programs before smaller ones. However, this simple load-the-biggest-
first method might not always be the most efficient.  Sometimes, you
might have to juggle the load order to get the most out of the upper
memory area.

For example, suppose you want to load the following three programs
into UMBs:

   PROGRAM1.EXE   2K
   PROGRAM2.EXE   2K
   PROGRAM3.EXE   3K

Suppose you have two UMBs available; one is 4K in size; the other is
3K in size. (You can find out the sizes of individual UMBs by issuing
the MEM /P command. For more information, see page 519 of the
"Microsoft MS-DOS User's Guide and Reference.")

As you can see, PROGRAM3.EXE is the largest, at 3K. If you load
PROGRAM3 first, MS-DOS puts it into the largest UMB (4K). Since
PROGRAM3 doesn't use the entire 4K of space in that UMB, an additional
kilobyte of memory is left unused. The next program, PROGRAM1 (2K),
fits into the 3K UMB, again leaving an unused kilobyte of memory.
However, PROGRAM2 also needs 2K of contiguous space, and will not fit
into either of the 1K UMBs that remain. This is an example of when
it's not as efficient to load the largest program first.

A more efficient method would be to load PROGRAM1 (2K), then PROGRAM3
(3K), and then PROGRAM2 (2K). Then, all three programs would fit into
UMBs. MS-DOS would load PROGRAM1 into the 4K UMB, leaving 2K of space.
PROGRAM3 would then fit into the next largest UMB (3K), and PROGRAM2
would fit into the 2K remaining.

Figuring Out a Program's Memory Requirements
--------------------------------------------

A program's memory requirements determine what size UMB it needs.
Unfortunately, it can sometimes be difficult to figure out what size
UMB a particular program needs, since this depends on how and when the
program allocates memory. In general, programs fall into one of two
groups:

 - Most programs need a UMB that is at least as large as the program's
   size while it is running.

   To find out this size, issue the MEM /C command while the program
   is running. In most cases, if there is a UMB of that size
   available, the program should fit into that UMB.

 - Some programs need a UMB that is at least as large as the program's
   file size.

   Such programs use a lot of memory during startup and require less
   memory once they are running. Such a program initially needs a
   large UMB; but, after it has started, the program relinquishes some
   memory that can then be used to load the next program.

The following table lists some common Microsoft device drivers and
memory-resident programs that can run in the upper memory area. The
table specifies how to determine the size of UMB that each program
needs: by checking the program's size while it is running, or by
checking its file size.

   Program Name   Size of UMB It Needs
   ------------   --------------------

   ANSI.SYS       File size
   DISPLAY.SYS    Size while running
   DRIVER.SYS     File size
   EGA.SYS        File size
   MOUSE.COM      File size
   MOUSE.SYS      File size
   PRINTER.SYS    Size while running
   RAMDRIVE.SYS   Size while running
   SMARTDRIVE.SYS Size while running
   SETVER.EXE     File size
   APPEND.EXE     Size while running
   ASSIGN.COM     Size while running
   DOSKEY.COM     Size while running
   FASTOPEN.EXE   Size while running
   GRAFTABL.COM   File size
   GRAPHICS.COM   Size while running
   KEYB.COM       File size
   MIRROR.COM     Size while running
   NLSFUNC.EXE    File size
   SHARE.EXE      Size while running

Juggling the Load Order Between Your CONFIG.SYS and AUTOEXEC.BAT Files
----------------------------------------------------------------------

Most device drivers are loaded from your CONFIG.SYS file, and most
memory-resident programs from your AUTOEXEC.BAT file. MS-DOS processes
your CONFIG.SYS file first, and then executes the commands in your
AUTOEXEC.BAT file. This limits your ability to manipulate the load
order of your device drivers and programs, since the device drivers in
your CONFIG.SYS file will always load before the programs in your
AUTOEXEC.BAT file.

The following tips can help you balance the use of UMBs between device
drivers and memory-resident programs:

 - In your CONFIG.SYS file, start only the largest device drivers
   using the DEVICEHIGH command. If you use device drivers that are
   smaller than the largest memory-resident programs that load from
   your AUTOEXEC.BAT file, start those drivers using the DEVICE
   command. (Use the DEVICE command to load HIMEM.SYS and EMM386.EXE,
   since you cannot run these drivers in UMBs.)

 - In your AUTOEXEC.BAT file, start your largest memory-resident
   programs using the LOADHIGH command.

 - If your mouse comes with both a MOUSE.SYS and MOUSE.COM file, you
   can start your mouse driver from either your CONFIG.SYS or
   AUTOEXEC.BAT file. This way, you can load the mouse driver at any
   point in the startup process (as long as you load it after
   HIMEM.SYS and EMM386.EXE).

    - To load the mouse driver into UMBs from your CONFIG.SYS file,
      use the DEVICEHIGH command to load the MOUSE.SYS file.

    - To load the mouse driver into UMBs from your AUTOEXEC.BAT file,
      use the LOADHIGH command to load the MOUSE.COM file.


ADJUSTING EMM386 TO PROVIDE MORE UMBS
=====================================

You can adjust EMM386 to allocate additional space in the upper memory
area. (This is particularly useful if you have to start EMM386 with
the RAM switch to make expanded memory available to programs.) First,
carry out the steps in Procedure 1. After carrying out Procedure 1, if
you still cannot load programs and device drivers into UMBs, carry out
the steps in Procedure 2.

Procedure 1: Including Specific Portions of the Upper Memory Area
-----------------------------------------------------------------

Certain addresses in the upper memory area are normally reserved for
use by hardware and video drivers; EMM386 does not usually make these
areas available as UMBs. However, on many systems, the hardware and
video drivers do not use all the reserved memory addresses. The
remaining addresses can be included by EMM386 for use as UMBs. To
instruct EMM386 to include these unused areas, you use the I switch
after the DEVICE command that starts EMM386.

To allocate additional space in the upper memory area for use as UMBs,
follow these steps:

1. Create an MS-DOS startup disk. To do so, insert a formatted floppy
   disk in drive A and type the following:

      sys c: a:

2. Copy your CONFIG.SYS file to the startup disk by typing the
   following:

      copy c:\config.sys a:\

3. Edit your original CONFIG.SYS file. To edit the file using MS-DOS
   Editor, type the following at the command prompt:

      edit c:\config.sys

4. Locate the DEVICE command for EMM386.EXE, and insert the I switch
   in front of the RAM or NOEMS switch. The I switch specifies a range
   of addresses in the upper memory area, and tells EMM386 to allocate
   that memory for use as UMBs. The value you specify for the I switch
   will depend on your computer and monitor type.

    - If your computer is not an IBM PS/2 and does not have a
      monochrome monitor, add the i=E000-EFFF and the i=B000-B7FF
      switches before the RAM or NOEMS switch, as follows:

         device=c:\dos\emm386.exe i=E000-EFFF i=B000-B7FF ram

    - If your computer is not a PS/2 and has a monochrome monitor, add
      the i=E000-EFFF switch before the RAM or NOEMS switch, as
      follows:

         device=c:\dos\emm386.exe i=E000-EFFF ram

    - If your computer is an IBM PS/2 and does not have a monochrome
      monitor, add the i=B000-B7FF switch before the RAM or NOEMS
      switch, as follows:

         device=c:\dos\emm386.exe i=B000-B7FF ram

    - If your computer is an IBM PS/2 with a monochrome monitor, see
      Procedure 2.

5. If you're using MS-DOS Editor, choose Exit from the File menu. When
   MS-DOS Editor displays a dialog box prompting you to save your
   file, choose Yes, or press ENTER.

6. Restart your computer by pressing CTRL+ALT+DELETE.

   If your computer fails when you start it, the memory range you
   specified for EMM386 is probably being used by hardware or video
   display drivers. In that case, insert your startup disk in drive A
   and restart your computer. Then, edit your CONFIG.SYS and remove
   the I switch(es) you added to the DEVICE command for EMM386.
   Contact Microsoft Support Services for further assistance.

7. After your computer starts, check whether your programs loaded into
   UMBs successfully. To do so, type the following at the command
   prompt:

      mem /c |more

   This command displays the contents of your computer's conventional
   and upper memory, and shows where in memory each program is
   running. (For more information about the MEM /C command and UMBs,
   see page 320 of the "Microsoft MS-DOS User's Guide and Reference.")

Procedure 2: Reducing the Space Set Aside for Use with Expanded Memory
----------------------------------------------------------------------

Starting EMM386 with the RAM switch makes fewer upper memory blocks
(UMBs) available than starting it with the NOEMS switch. If programs
or device drivers do not load into UMBs when your computer starts,
there might not be enough UMBs to run those programs. This is because
using the RAM switch sets aside 64K of the upper memory area for use
with expanded memory. The remaining UMBs might not be large enough to
run your programs, even if you were able to include additional
addresses by following Procedure 2.

You can instruct EMM386 to set aside 16K of the upper memory area,
rather than 64K, for use with expanded memory. This makes more UMBs
available, but programs that use expanded memory might run less
efficiently. Follow these steps:

1. Exit from Windows, and type the following at the command prompt:

      emm386

   EMM386 displays information about its current memory-management
   activities. Locate the line that reads "Page frame segment" and
   write down the hexadecimal address on that line. In the following
   example, the page frame segment is E000.

     Page frame segment . . . . . . . . . E000  F

2. Edit your original CONFIG.SYS file. To edit the file using MS-DOS
   Editor, type the following at the command prompt:

      edit c:\config.sys

3. Locate the DEVICE command for EMM386.EXE, and insert the P0 switch
   before the RAM switch. The P0 switch should specify the address you
   obtained from EMM386 in Step 1. For example,  if the page frame
   segment was E000, the DEVICE command might appear as follows:

      device=c:\dos\emm386.exe i=E000-EFFF p0=E000 ram

4. If you're using MS-DOS Editor, choose Exit from the File menu. When
   MS-DOS Editor displays a dialog box prompting you to save your
   file, choose Yes, or press ENTER.

5. Restart your computer by pressing CTRL+ALT+DELETE.

   If your computer fails when you start it, insert your startup disk
   in drive A and restart your computer. Then, edit your CONFIG.SYS
   file and remove the P0 switch you added to the DEVICE command for
   EMM386. Then, save the file, restart your computer, and repeat
   Procedure 2; be sure to check the page frame address carefully.

6. After your computer starts, check whether your programs were loaded
   into UMBs successfully. To do so, type the following at the command
   prompt:

      mem /c |more

   This command displays the contents of your computer's conventional
   and upper memory, and shows where in memory each program is
   running. (For more information about the MEM /C command and UMBs,
   see page 320 of the "Microsoft MS-DOS User's Guide and Reference.")

You have solved the problem if your programs and device drivers are
running in UMBs.

If your programs and drivers still do not load into UMBs, it is
possible that your system simply does not have enough UMBs available
to run those programs. See your computer's hardware documentation for
information about which addresses in the upper memory area are in use;
contact Microsoft Product Support Services for further assistance.


RELATED INFORMATION
===================

See the following pages in the "Microsoft MS-DOS User's Guide and
Reference" for additional information:

 - How to set up your computer to run programs in the upper memory
   area, pages 313-326

 - Tips for troubleshooting the process of running programs in the
   upper memory area, page 327

 - Information about the DEVICEHIGH command, page 435

 - Information about the LOADHIGH command, page 518

 - Information about the MEM command, page 519

 - Information about EMM386.EXE startup parameters, page 605

 - Information about HIMEM.SYS startup parameters, page 610