DOSBox
DOSBox is a program which emulates a Pentium-class PC running MS-DOS. Development is focused on compatibility with games, but the vast majority of DOS software works just fine under DOSBox.
The project was born out of frustration with DOS incompatibility with the various versions of Windows available around 2000. Microsoft later dropped support for 16-bit software completely in 64-bit versions of Windows. DOSBox provides a means of continuing to enjoy older Windows games that cannot be run under current versions of Windows by running Windows 3.1 or even Windows 95 [1] inside DOSBox since pre-NT Windows used to run under DOS. Yes, the compatibility is that good.
Anyone used to using DOS will be right at home with the DOSBox shell, which not only implements most DOS commands, but also includes the ability to change the configuration from the DOSBox command-line using built-in "programs" (although most users will probably just edit the dosbox.conf file in a text editor).
The official distributions do not support functions like printing, given the emulator is geared towards gaming. Of course, given the program is distributed under the GPL, you can always make your own custom compile if you need to.
Another advantage the program has is the ability to support modern USB joysticks and gamepads within the older programs. And even if a game was never meant for them, you can use addons like Joy to Key to add the ability. This runs in the background and routes each button press of your gamepad/joystick to a button on the keyboard which the game can support. It can also imitate modem connection and tunnel IPX into TCP/IP, i.e. allow to play over Internet games designed for old style local network [2].
DOSBox has proven to be rather popular with commercial developers who originally wrote their games for DOS and have started selling them again.
ID Software bundles DOSBox with the Steam versions of a number of their games including:
- Commander Keen
- Wolfenstein 3D and Spear Of Destiny
- Doom and Doom II
- Heretic
- Hexen
Apogee's games available through their online store also come with DOSBox if the game doesn't run natively under Windows.
When Bethesda re-released The Elder Scrolls: Arena and The Elder Scrolls II: Daggerfall for free on their website, the updated installation instructions for the games explicitly stated you would need DOSBox.
Also, whenever Good Old Games re-releases PC-DOS-classic games of past times, you can expect it to be possible thanks to DOSBox.
You can download DOSBox from http://www.dosbox.com/. It has its own documentation wiki, for dosbox.conf options see here.