Installing and Configuring MS-DOS Programs In Windows XP


By description, all programs initially written for MS-DOS are 16-bit programs. As such, they run on a virtual machine next to their 16-bit counter parts developed for Windows 3.x. To control the performance of MS-DOS-based programs, you use a properties dialog box whose design hasn’t changed much as Windows 95. Custom property settings for each program are stored in a shortcut file called a program information file (PIF).

You are able to create many shortcuts (PIFs) for an only MS-DOS program, each with its own custom settings, such as a defaulting data file or working directory. When you right-click the icon for an MS-DOS executable file and create any changes to its properties, Windows saves your changes in the same folder, making or updating a file with the similar name as the executable file and the extension .pif. You are able to change the name of the shortcut file or move it to another folder.

The PIF format is dual and can’t be edited apart from during the properties dialog box. Right click the icon for the MS-DOS program’s executable file to display this dialog box, which adds four tabs including options that are completely available to MS-DOS programs. Using the Misc tab, shown in Figure 1, for example, you can disable Windows shortcut keys that struggle with shortcuts in the MS-DOS program. Options on other tabs permit you to adjust the amount of memory allocated to a program, indicate the program’s initial display mode (full-screen or windowed), and alter the icon associated with the program, among other things.


Figure 1. The Font, Memory, Screen, and Misc tabs in this dialog box control settings that are exclusive to MS-DOS programs.

You be able to run any character-based program written for MS-DOS in full-screen mode or in a window. (Graphics-based programs run only in full-screen mode.) If you run a program in full-screen mode, it looks accurately like it does when you run it under MS-DOS. If you run it in a window, it has a title bar, a Control menu, and other known window management features.

Running some MS-DOS programs properly might needs that you modify the system configuration used by the MS-DOS virtual machine. Two files, Autoexec.nt and Config.nt, provide this function in Windows XP.

These two files supply a purpose similar to that of Autoexec.bat and Config.sys in MS-DOS and Windows 95/98, with more than a few important differences:

● Autoexec.nt and Config.nt are situated by default in the %SystemRoot%\System32 folder. (The matching files on an MS-DOS or Windows 95/98 machine are in the root folder of drive C.)

● In Windows XP (as in Windows 2000), you be able to create custom versions of Autoexec.nt and Config.nt for exact applications. To associate your custom configuration files with a particular application, copy the default files to a divide location and edit them as needed. Next, open the properties dialog box for the MS-DOS program, click the Advanced button on the Program tab, and then enter the correct locations as shown below. (Note that this dialog box contains a Compatible Timer Hardware Emulation check box. This option inflicts a performance penalty, so you should select it only if your application won’t run with the box cleared.)


● Commands you enter in these two files have an effect on only the MS-DOS subsystem. Many commands, such as Buffers and Break, are ignored, even though they can be entered for compatibility purposes when an MS-DOS program perseveres that they be present. Windows XP contains its own versions of Himem.sys, Ansi.sys, Country.sys, and Setver.exe. Avoid using the following unsupported and unnecessary Windows 95/98 drivers in Config.nt: Emm386.exe, Smartdrv.sys, Ramdrive.sys, and Dblspace.sys/ Drvspace.sys. Windows XP ignores all entries in Autoexec.nt except those defined by Set or Path commands, which it adds to the startup environment for that MS-DOS virtual machine.