TWENTY-SIX years ago, Microsoft negotiated to buy an obscure piece of software that would transform it into a computer industry powerhouse.

The software was called QDOS, short for Quick and Dirty Operating System, and Microsoft needed it for the personal computer that IBM was developing. Various accounts say Bill Gates’ partner, Paul Allen, bought QDOS from programmer Tim Paterson of Seattle Computer Products for between $50,000 and $100,000. Microsoft then parlayed that into billions of dollars by charging IBM a license fee of up to $50 for every copy of the operating system—renamed MS DOS— that was sold with millions of its new PCs. The billions that DOS funneled into the upstart company gave it the financial muscle to develop many other products that followed, including MS Office and Windows, and allowed it to dominate the PC software business in decades to come.

Of course, many young computer users who grew up using Windows never experienced DOS or character-based computing.

In 2001, when Gates launched Windows XP, he also declared the end of the DOS era. Unlike all earlier versions of Windows, XP would no longer have DOS running underneath.

Still, old habits die hard, and a surprising number of people still run DOS applications even today. Some of them are tailor-made applications like point-of-sale programs that do just one specific task reasonably well—and cheaply. Others are more general programs like word processors that users have grown accustomed to.

When I first came to Manila Standard Today, for example, one of the senior editors was still running Wordstar in a DOS window on a Windows PC. From the editor’s point of view, the solution made perfect sense—he could write and edit efficiently using a word processor that he had mastered long ago. Instead of fiddling with new formatting commands, he could concentrate on typing.

On the Web, I found a 1996 essay by science fiction author Robert J. Sawyer, extolling the virtues of Wordstar for DOS. Ten years later, he’s still using Wordstar 7.0, running in a DOS window in XP—and writing his 19th book with it.

I know where he’s coming from. I, too, was a Wordstar for DOS (Version 5) holdout many years after it became fashionable to use MS Word for Windows, though I finally had to give it up.

If you’re running XP, you can still get a taste of DOS. Just go to START, RUN, type COMMAND and hit Enter to get a simulated DOS window.

I was pleasantly surprised to find you can also run old DOS programs on a Linux or Mac OS X machine. An open source program called DOSBox emulates an Intel X86 PC —complete with sound and graphics—to enable users to run old DOS programs that probably wouldn’t run on newer Windows PCs and would never have run on other machines such as Macs.

Versions of DOSBox are available for Linux, FreeBSD, Windows and Mac OS X, so I gave it a whirl on my Ubuntu Linux desktop PC and my Mac iBook. Both versions were easy to install and use, especially if you remember some old DOS commands. Unlike the original DOS, you do need to mount a virtual C: drive by pointing DOSBox to a directory on your hard disk where you’ll store your DOS programs.

In five minutes, I was typing out a document on an old copy of Wordstar that I scrounged up. Rather quickly, the old commands like Ctrl KB and Ctrl KK to mark a block of text—came back to me. Only now I was typing them on a Mac. Wordstar ran on the Ubuntu PC without a hitch, too, though I’m sure trying to print from either would be a significant challenge. After all, one of the biggest pains about DOS computing was the need to install device drivers.

A search for free DOS programs brought me to an excellent site called Interesting DOS Programs based in Trinidad and Tobago. The site also has an extensive page of links to other DOS-related pages.

If you have a hankering to play the old PC games, there are DOS Games and DOS Games Archives. A free adventure game I downloaded, Lure of Temptress—the first from Revolution Software—ran perfectly in DOSBox on the iBook, but I haven’t yet figured out how to configure the sound to work on Ubuntu.

Going through long lists of applications and games available online, one thing became apparent. Notwithstanding its official demise in 2000, DOS lives on—even without Microsoft.