The DOS and Don'ts of Retro Gaming

A game of Doom, anyone? Or perhaps Wolfenstein 3D, X-COM: UFO Defense, or Warcraft are more your speed? For many of us, these games bring back warm, nostalgic feelings of a simpler time when days were spent hacking away on an early PC running DOS. Those days may be far off in the rearview mirror now, but that certainly can’t stop us from trying to recreate those experiences from time to time.

As technological progress continues on, it is getting harder to run this old software, however. Sure, there is DOSBox — the excellent free and open-source x86 emulator that makes running DOS a breeze — but sometimes emulation is not an authentic enough experience and we want the real deal. One option is to dust off an old machine from the attic and see if it still boots up, or buy something on a secondary market. But what if you just want to run DOS right on a modern machine?

As you might expect, running a 30-plus-year-old operating system on a modern computer is not exactly straightforward. Assuming you have an x86 architecture CPU, you have a decent starting point since these processors are backwards compatible to the beginning of time. But what about BIOS support, which DOS relies on, yet has been rapidly disappearing from modern machines? And how about driver support for sound cards, network devices, and so on? Yeah, good luck with that!

Maker and retrocomputing enthusiast Yeo Kheng Meng was bound and determined to natively run MS-DOS 6.22 (the last standalone version to be released) on a modern laptop computer and did not let these issues get in the way. He managed to make it happen — with a few caveats — and has detailed the steps necessary to repeat the feat.

Modern computers have replaced the traditional BIOS with UEFI, however, they have also generally maintained BIOS support for backwards compatibility. That all started to change several years ago though, which makes the job of running DOS natively much more challenging now. But Meng did some research, and found that some manufacturers have still not dropped BIOS support, at least not in all of their models. So he found a ThinkPad with backwards compatibility as a starting point.

Next, a number of settings needed to be configured, like enabling UEFI-CSM legacy mode, and disabling secure boot and kernel DMA protection. Some Thunderbolt-related options also needed to be tweaked to make these devices available to DOS.

Thanks to the backwards compatibility of x86 chips, that was enough for Meng to start the DOS installation process. He chose to install the operating system on an external USB flash drive, as that was just simpler given the operating system’s requirement for a legacy MBR partition table. To get audio working, the SBEMU driver, which emulates Sound Blaster cards and works with modern sound hardware like Intel HD Audio, was utilized.

As far as networking is concerned, the laptop’s onboard network adapter proved to be a no-go. But after experimenting with three other network adapters, connected via Thunderbolt, Meng found some suitable options, each with its own pros and cons. None of them were especially fast, but they got the job done and even allowed Meng to use ChatGPT from DOS.

For most people, DOSBox or an older PC are going to be the best options to satisfy the need to play some classic DOS games. But if you are determined to run the real deal on your daily driver, Meng’s write-up will show you the way.