Configuring DOS emulation

By Darren Prescott

The default settings of the DOS emulator will work for most people, but there will always be games that require EMS or large amounts of conventional memory, which aren't provided by default. Under plain MS-DOS, the configuration files autoexec.bat and config.sys are used to load devices and set up memory allocation. These live on under Windows XP, albeit with slight changes to the file names and syntax.

Windows XP uses two files when you start up the DOS emulator; config.nt is the direct replacement for config.sys and autoexec.nt is XP's equivalent to autoexec.bat. Getting the most memory available for DOS applications involves creating your own config.nt and autoexec.nt files - the steps below show you how to get enough base memory and EMS to run almost anything.

@echo off
SET BLASTER=A220 I5 D1 P330 T3

dos=high,umb
device=%SystemRoot%\system32\himem.sys
emm=ram
files=20

This gives you a bare bones DOS setup, including setting up Soundblaster emulation. Next, follow the steps below to create a shortcut icon for DOS, with the config files you've just created:

Note: some games, such as those that use DOS extenders to access extra memory, won't run with the above setup - you'll get an error message such as the one below.

If this happens, either type dosx at the DOS prompt or include the following in your autoexec.nt file:

lh %SystemRoot%\system32\dosx

Note: the default settings for the DOS emulator include the following line in autoexec.nt; if you get CD related errors in DOS games then you'll need to add the following to your autoexec.bat file.

lh %SystemRoot%\system32\mscdexnt.exe

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