My reason for writing this article is simple. Lately I've seen A LOT of people commenting in various threads in the Gaming forum about how they wish they could play some old DOS game or another. Well I've been under the impression for awhile that the information I'm about to provide was actually a matter of common knowledge - though it appears that I'm wrong. So without further ado....

Our first category of tools are what are known as "System Emulators". These programs essentially pretend to be an entire 486/Pentium level machine. Using these programs you can play old games, install operating systems, and even play around with old pieces of hardware that may not otherwise work with modern Operating Systems.

1. DOSBox http://dosbox.sourceforge.net
This program just rocks. If you want to play most old DOS games - this pile of code is your best friend. Why? Well it emulates an entire PC, provides its own DOS environment, and works on Linux, Windows and Mac OSX platforms. This means that you will not have to intall MS-DOS and play with memory configurations or device drivers, or disk images, or old hardware. This emulator provides full MPU-401, Disney Sound Source, Roland, SB16 and Adlib sound capabilities. (No you dont even have to set the BLASTER environment variable) It allows for both EMS and XMS memory. You can "mount" directories on your harddrive within the virtual DOS environment which makes it easy to access all of your old software. Not to mention the fact that using special key combinations detailed in the documentation, you can adjust the amount of CPU cycles per second that DOSBox will attempt to emulate. This makes it very easy to adjust the speed of the emulation to match the game in question.

Now this program is still under development but do not stop reading yet. The current version (.60) does provide for the partial capability to run protected mode software (i.e. duke nukem 3d, doom....). More and more progress is being made on this program and its various features each and every day though. If you are using Windows you can check out the Development forum for a link to an ftp site where the latest cvs win32 binaries are kept. For OSX and Linux feel free to download and compile the code directly from the CVS repository. The current cvs version has made major strides in protected mode emulation and measurable progress is being made on a daily basis. Many popular games are running smoothly right now in the .60 release version though. In fact I would venture to say that the majority of dos games will run flawlessly on this emulator as of right now. There is a compatibility list on the DOSBox site right now though it doesn't include any updated stats for the CVS version. I would suggest checking the forums at the DOSBox site for more information.

2. Virtual PC http://www.connectix.com
I'm sure most of you have heard of Virtual PC given that its new owner, Bill Gates is quite popular. When it comes to general system emulation Virtual PC is pretty much number 1 in my book. When it comes to old DOS games though I find that Virtual PC is quickly losing ground as the premier DOS Games Emulator when compared against DOSBox. However there are still a few classics which play quite well in Virtual PC (Crusader, Zone66) that otherwise you won't be playing without a real machine handy.

Keep in mind that Virtual PC is not a free piece of software. Last time I purchased it (either the Mac or PC version) it cost me around $99 to purchase it with a DOS based Operating System. You will have to spend the time and effort configuring the DOS memory management correctly. As you may or may not recall this wasn't very fun and hasn't gotten any more fun as the years have gone by. Also with Virtual PC sound card emulation is somewhat limited to Soundblaster and Adlib support. Also if you choose to install MS-DOS 6.x or 5.x you will have to adhere to keeping your chosen partitions under the 2 gigabyte FAT 16 limit so that your older software can be easily accessed.

3. VMWare http://www.vmware.com
This is another commercial option available for both Windows and Linux. I personally haven't used Vmware in quite awhile so I don't have very much to say about it. From what I understand the primary reason why this emulator is not very popular for DOS gaming has to do with it's lack of any real sound emulation. Essentially with special drivers it allows a given OS to generate PCM sound and that's about it. VMWare is also the most expensive of the bunch weighing in at about $300. This pretty much puts it out of reach of most DOS gamers since one could easily build a "top end" older machine for that price.

4. DosEMU http://www.dosemu.org/
Last but not least we have DosEMU. Many of you Linux users probably have used this application at one time or another. Over the years it seems to have faded into obscurity from what I have seen though. It plays some games decently as I recall (it's been a few years since I had a use for it personally). Its claim to fame though came a few years ago when a patch was released that allowed Star Control 2 to be being flawlessly within the DosEMU environment. This was quite the event since no emulator had managed to accomplish this feat before due to the odd timing used within SC2. If you are feeling lucky go ahead and give this one a try. Note: This program will only run under x86 Linux. It's compatibility is quite limited and configuring it is a pain. You have been warned.

5. Bochs http://bochs.sourceforge.net
Ok I lied. There is one more. Essentially Bochs is an x86 system emulator that has developed over the last few years. Bochs focuses more on accuracy and reproducable results than it does on raw speed however. This having been said, I've heard rumors of successes running certain difficult DOS games using Bochs. Like Virtual PC or VMWare you will have to install your own Operating System. You will have to configure your chosen version of DOS. In the event that you are forced to choose between Bochs and Virtual PC, I would definitely recommend saving your dough and shelling out for Virtual PC when the rubber hits the road. To put it bluntly speed is the primary issue here. Bochs can barely boot Windows 2000 on my 2.6 ghz Xeon Dualie and Virtual PC can run Windows 2000 smooth as silk. This speed difference translates over to other Operating Systems as well.

But if these options aren't appealing to you.... there are other options. Read on for more information: