Windows XP tuning for DOS programs 
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 Windows XP tuning for DOS programs

I found this XP tuning note on comp.os.geos.misc.  Geos was (is) a DOS
graphical user interface that came out a day late!

Anyway, lots of good XP nuggets for running DOS apps.  From c.o.g.m.:


While going through the install process you will be asked if you
want to change the settings in your AUTOEXEC.BAT and/or
CONFIG.SYS files.  Say "No" to both.  You will change your
CONFIG.NT file in step 5 below.

 1. Right click the shortcut you use to run Ensemble and choose
    Properties from the menu.
 2. On the Shortcut tab, check the Target and Start in
    boxes to make sure they name the drive and folder where
    Ensemble is installed (usually C:\Ensemble).
 3. In XP, on the Compatibility tab set Ensemble to run in
    Windows 95 mode.
 4. Click APPLY.
 5. Using Windows Notepad or a text editor, examine your CONFIG.NT
    file (usually located in C:\WINNT[or WINDOWS]\SYSTEM32).
    It should contain these settings:
      dos=high, umb
 6. To be able to use your floppy drive (A:) edit your geos.ini file
    from Windows as follows.  In the [system] section add the line:
      drive a = 65535
    This will replace the floppy drive icon with a hard drive icon,
    but at least the drive will be usable.

NOTE: Ensemble will run only in full screen mode, and you may
need to adjust your Ensemble and/or your Windows screen resolution
and color depth to match each other.  In some cases Ensemble may
run in only 640x480 16 colors.  In some cases users have reported that
must press the CTRL key either during or after Ensemble shuts down
to successfully return to Windows XP.

The above steps will normally get Ensemble running, but you can do some
additional tweaking.
 1. If you have Windows running at a screen resolution greater than
    800x600, you can run Ensemble in an 800x600 window by downloading
    and installing a package of drivers for Ensemble that is available
    at  Go to the Downloads section, select Utilities
    and look for the "NDO and WinNT" download.
 2. The following article contains additional information on running
    older applications in Windows XP.

September 3, 2002
Old Apps Find A New Home On Windows XP

By Brian Proffit

Microsoft Windows 9x users have been reluctant to move to Windows NT for
years, but around the same time it released Windows XP, Microsoft dropped
its support for Windows 95. Industry insiders speculate that Windows NT 4.0
support will be the next to go. In effect, options are shrinking for those
who want to hang on to the older OSs.

The reluctance to upgrade has been based on two factors: heavier hardware
requirements and poor compatibility with applications not specifically
written for Windows NT.

The hardware has caught up, to the point that even today's low-end systems
are sufficient for Windows XP. But what about application compatibility?
Although on the surface, Win XP is the Windows version least compatible with
its predecessors, it has special tools that give Win XP users more options
for compatibility than ever before. These tools, some obvious and some
hidden, let you tweak the environment so that many older applications will

Running DOS Programs

DOS programs are the oldest, and since Microsoft dropped the DOS
Compatibility Mode from Windows XP, you might think it dropped support for
DOS programs altogether. In fact, new options in Windows XP may make running
DOS programs easier.

Right-click on a DOS program, and select Properties from the pop-up menu.
Most of the tabs in the Properties dialog are familiar, but the
Compatibility tab is new. This tab lets you set the program to run in
256-color mode and at a resolution of 640-by-480. You can also disable the
default visual themes that Windows XP imposes on programs.

There's also a less obvious and more powerful tool. With DOS, you could
tune the environment for your programs by modifying the Config.sys and
Autoexec.bat files. In some cases, you'd reboot the system with a special
configuration just for one program and then go back to the normal setup to
run other programs. Windows XP lets you define a customized Config.sys and
Autoexec.bat for each of your DOS programs.

Here's how it's done. First, copy the C:\Windows\System32\Config.nt and
C:\Windows\ System32\Autoexec.nt files to the directory of your DOS program,
then edit them to reflect the configuration you want. Save them with a new
name. Bring up the Properties dialog for the DOS program, move to the
Program tab, and click on the Advanced button.

Enter the Config and Autoexec filenames you created for the program and
Windows XP will run the program in its own customized environment. This
dialog also lets you try to slow down DOS programs that performed actions
based on the clock speed of your processor. Programs that ran well on a
50-MHz system can be unusable on an 850-MHz system without this emulation.

Windows Programs Not Designed for XP

The three main reasons older Windows programs fail under Windows XP are that
they query for a specific Windows version number, they expect results that
older versions of a Windows API call return, and they expect user folders to
be in a different location or format. These problems can be fixed by setting
the Windows program to run in compatibility mode.

Right-click on a Windows program, and select Properties. If you click on the
Compatibility tab, you will see a drop-down list that lets you set the OS
best suited for this program. Click in the Compatibility mode box, and
select the operating system. Using this mode will activate a set of patches
(called shims) that make Windows XP treat the program as an earlier version
of Windows would.

What if you aren't sure which environment to use, or the program has other
compatibility problems? There is a powerful package hidden on the Windows XP
CD that will help you fine-tune your application environment.

The Application Compatibility Toolkit

In the \Support\Tools directory of the Windows XP CD, Microsoft included an
Application Compatibility Toolkit (ACT). An update (Version 2.5) came out in
April, and you can download it from
The ACT contains four tools for improving application compatibility.

Two of the tools, Application Verifier and PageHeap, are designed for
software developers, who use them with a de{*filter*} to test areas that might
pose problems under Windows XP. But the other two, QFixApp and Compatibility
Administrator, can help end users tweak the environment so that older apps
run successfully.

QFixApp lets you test a number of low-level tweaks on a specific
application. We don't have enough space to discuss each of the 199
applicable fixes, so we'll cheat and show you a couple of shortcuts to
finding the particular shims that will restore your program.

Open QFixApp, and select the application you need to work on. Click on the
Layers tab, and select a layer. The layers in QFixApp correspond to the
compatibility modes we saw earlier in the application's Properties dialog.
Select a layer, such as Win95, and then select the Fixes tab. You can see
that the Win95 compatibility mode is a predefined set of 54 shims (Figure
1). This number can fluctuate, however, depending on whether you've
installed the latest patches and updates.

From there, you can tailor the list to add or remove shims. For example, if
your application changes the screen mode and your system is stuck there when
the program ends, scroll down and try the ForceTemporaryModeChange fix. As
you select a fix, a description of its function appears in the lower pane.
Click on the Run button to test the effect of the changes on your
application. When you close QFixApp, the environment changes you've made
will be stored with the executable. Until then, you can select and deselect
shims as you wish.

Browsing Predefined Fixes

You don't have to search for fixes by trial and error. Microsoft includes a
number of predefined fixes, and you can browse those for tips.

Open the Compatibility Administrator tool, and expand System Database |
Applications. A good start in tweaking your application is to find a similar
program in the database. For example, if you are working with a program in
the 102 Dalmatians series, select one of the programs in that series for
which Microsoft has already defined fixes. Cross-referencing with QFixApp,
you see that the EmulateHeap and EmulateMissingEXE fixes are already
included in the Win95 compatibility mode, but the IgnoreAltTab fix isn't.
Try setting this shim in QFixApp and running your application.

Note that Windows XP provides predefined fixes for the application's setup
program as well as the app itself. You can group the fixes associated with
an application into one package.

Compatibility Administrator becomes even more important in corporate IT
departments that need to support legacy applications. Once you have
determined which set of fixes is required, click on New and a new database
is created under Custom Databases. With the new database selected, click on
Fix to open a wizard that will guide you through creating an application fix
set for this database. Follow the prompts to choose a compatibility mode,
and set the additional shims you identified during your QFixApp testing.
Finally, group related files with this application. Windows XP will try to
find these for you when you click on Auto-Generate. Use File | Save to save
the custom database to an SDB file that you can send to other computers.

If you have a number of legacy applications that all require similar sets of
fixes, you can create a new compatibility mode in your custom database. With
the database highlighted, click on Mode. You can name the mode Legacy and
select the set of fixes to be applied when this mode is selected. Once the
database has been saved and installed, you can apply the whole set of fixes
to a new app simply by selecting the Legacy compatibility mode. To add this
mode to another system, copy the SDB file to the other computer and run
Sdbinst.exe to install it.

The Windows NT platform earned its reputation for being reluctant to run
older applications. But with the new tools in Windows XP, you have a better
chance than ever of keeping your legacy programs going until they can be


Wed, 08 Jun 2005 13:42:37 GMT  
 [ 1 post ] 

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