dos

43 Articles

Jenny’s Daily Drivers: FreeDOS 1.4

August 6, 2025 by 62 Comments

When I was a student, I was a diehard Commodore Amiga user, having upgraded to an A500+ from my Sinclair Spectrum. The Amiga could do it all, it became my programming environment for electronic engineering course work, my audio workstation for student radio, my gaming hub, and much more.

One thing that was part of my course work it couldn’t do very well, which was be exactly like the PCs in my university’s lab. I feel old when I reflect that it’s 35 years ago, and remember sitting down in front of a Tulip PC-XT clone to compile my C code written on the Amiga. Eventually I cobbled together a 286 from cast-off parts, and entered the PC age. Alongside the Amiga it felt like a retrograde step, but mastering DOS 3.3 was arguably more useful to my career than AmigaDOS.

It’s DOS, But It’s Not MS-DOS

The FreeDOS installation screen
Where do I want to go today?

I don’t think I’ve used a pure DOS machine as anything but an occasional retrocomputing curio since some time in the late 1990s, because the Microsoft world long ago headed off into Windows country while I’ve been a Linux user for a very long time. But DOS hasn’t gone away even if Microsoft left it behind, because the FreeDOS project have created an entirely open-source replacement. It’s not MS-DOS, but it’s DOS. It does everything the way your old machine did, but in a lot of cases better and faster. Can I use it as one of my Daily Drivers here in the 2020s? There is only one way to find out.

With few exceptions, an important part of using an OS for this series is to run it on real hardware rather than an emulator. To that end I fished out my lowest-spec PC, a 2010 HP Mini 10 netbook that I hold onto for sentimental reasons. With a 1.6 GHz single core 32 bit Atom processor and a couple of gigabytes of memory it’s a very slow machine for modern desktop Linux, but given that FreeDOS can run on even the earliest PCs it’s a DOS powerhouse. To make it even more ridiculously overspecified I put a 2.5″ SSD in it, and downloaded the FreeDOS USB installer image. Continue reading “Jenny’s Daily Drivers: FreeDOS 1.4” →

Ancient Pocket Computer Gets A USB-C Upgrade

January 31, 2025 by 9 Comments

Remember the ZEOS Pocket PC? Perhaps you knew it as the Tidalwave PS-1000. Either way, it was a small clamshell computing device that was first released all the way back in 1992, and perhaps most accurately known as a DOS-based palmtop. Over at [Robert’s Retro] on YouTube, one of these fine devices was put through a repair and a modern upgrade program.

[Robert] educates us on the basics of the machine as he sets about the routine repairs so familiar to anyone in the retrocomputing scene. The first order of business is to clean up the damage to the battery compartment, which had suffered corrosion from leaking AA batteries. We get a solid look inside, and a walk-through on how to modify the device to run off USB-C power. It’s as simple as wiring up a small power module PCB and integrating that into the case, but it’s a neat mod done well—and it makes toying with the device much easier in 2025.

[Robert] has a cause he’s pursuing, though, when it comes to these old palmtops. He’s trying to identify the name of the oddball connectors these things used for the parallel and serial interfaces, and ideally, a source for the same. If you’ve got a tip on that, drop it in the comments.

Funnily enough, these things were cloned like crazy back in the day, so you might even find one under another name in your retro travels. They might be old, but somehow, it’s impossible for a piece of tech to feel old when you’re hooking it up with a USB-C port. We’ve featured [Robert’s] work before, too!

Continue reading “Ancient Pocket Computer Gets A USB-C Upgrade” →

The Ultimate Distraction Free Writing Environment

January 2, 2025 by 42 Comments

The art of writing has become a cluttered one to follow, typically these days through a graphical word processor. There may be a virtual page in front of you, but it’s encumbered by much UI annoyance. To combat this a variety of distraction free software and appliances have been created over the years.

But it’s perhaps [Liam Proven]’s one we like the most — it’s a bootable 16-bit DOS environment with a selection of simple text and office packages on board. No worries about being distracted by social media when you don’t even have networking.

The zip file, in the releases section of the repository, is based upon SvarDOS, and comes with some software we well remember from back in the day. There’s MS Word 5.5 for DOS, in the public domain since it was released as a Y2K fix, Arnor Protext, and the venerable AsEasyAs spreadsheet alongside a few we’re less familiar with. He makes the point that a machine with a BIOS is required, but those of you unwilling to enable BIOS emulation on a newer machine should be able to run it in a VM or an emulator. Perhaps it’s one to take on the road with us, and bang away in DOS alongside all the high-powered executives on the train with their fancy business projections.

We recently talked about SvarDOS, and it shouldn’t come as a surprise that our article linked to a piece [Liam] wrote for The Register.

When It Comes To DOS, Don’t Forget DR-DOS.

December 25, 2024 by 45 Comments

Despite the latest and greatest Intel-derived computers having multi-core 64-bit processors and unimaginably fast peripherals, at heart they all still retain a compatibility that goes back  to the original 8086. This means that they can, in theory at least, still run MS-DOS. The venerable Microsoft 16-bit OS may now be long discontinued, but there is still enough need for DOS that the open-source FreeDOS remains in active development. The Register are here to remind us that there’s another open-source DOS on the block, and that it has a surprising history.

SvarDOS is an open source DOS distribution, and it’s interesting because it uses a derivative of the DR-DOS kernel, an OS which traces its roots back to Digital Research’s CP/M operating system of the 1970s. This found its way briefly into the open source domain courtesy of the notorious Caldera Inc back in the 1990s, and has continued to receive some development effort ever since. As the Reg notes, it has something FreeDOS lacks, the ability to run Windows 3.1 should you ever feel the need. They take it for a spin in the linked article, should you be curious.

It’s something which has surprised us over the years, that aside from the world of retrocomputing we still occasionally find FreeDOS being distributed, usually alongside some kind of hardware maintenance software. Even four decades or more later, it’s still of value to have the simplest of PC operating systems to hand.

It’s worth pointing out that there’s a third open-source DOS in the wild, as back in April Microsoft released MS-DOS version 4 source code. But as anyone who used it will tell you, that version was hardly the pick of the bunch.

Header: Ivan Radic, CC BY 2.0.

Running Stock MS-DOS On A Modern ThinkPad

August 22, 2024 by 33 Comments

It might seem like the days of MS-DOS were a lifetime ago because…well, they basically were. Version 6.22 of the venerable operating system, the last standalone release, came out back in 1994. That makes even the most recent version officially 30 years old. A lot has changed in the computing world since that time, so naturally trying to run such an ancient OS on even a half-way modern machine would be a waste of time. Right?

As it turns out, getting MS-DOS 6.22 running on a modern computer isn’t nearly as hard as you’d think. In fact, it works pretty much perfectly. Assuming, that is, you pick the right machine. [Yeo Kheng Meng] recently wrote in to share his experiments with running the final DOS release on his Intel-powered ThinkPad X13 from 2020, and the results are surprising to say the least.

To be clear, we’re not talking about some patched version of DOS here. There’s no emulator at work either. Granted [Yeo] did embrace a few modern conveniences, such as using a USB floppy drive emulator to load the disk images instead of fiddling with actual floppies, and installing DOS onto an external drive so as not to clobber his actual OS on the internal NVME drive. But other than that, the installation of DOS on the ThinkPad went along just as it would have in the 1990s.

Continue reading “Running Stock MS-DOS On A Modern ThinkPad” →

Microsoft Updates MS-DOS GitHub Repo To 4.0

April 26, 2024 by 30 Comments

We’re not 100% sure which phase of Microsoft’s “Embrace, Extend, and Extinguish” gameplan this represents, but just yesterday the Redmond software giant decided to grace us with the source code for MS-DOS v4.0.

To be clear, the GitHub repository itself has been around for several years, and previously contained the source and binaries for MS-DOS v1.25 and v2.0 under the MIT license. This latest update adds the source code for v4.0 (no binaries this time), which originally hit the market back in 1988. We can’t help but notice that DOS v3.0 didn’t get invited to the party — perhaps it was decided that it wasn’t historically significant enough to include.

That said, readers with sufficiently gray beards may recall that DOS 4.0 wasn’t particularly well received back in the day. It was the sort of thing where you either stuck with something in the 3.x line if you had older hardware, or waited it out and jumped to the greatly improved v5 when it was released. Modern equivalents would probably be the response to Windows Vista, Windows 8, and maybe even Windows 11. Hey, at least Microsoft keeps some things consistent.

It’s interesting that they would preserve what’s arguably the least popular version of MS-DOS in this way, but then again there’s something to be said for having a historical record on what not to do for future generations. If you’re waiting to take a look at what was under the hood in the final MS-DOS 6.22 release, sit tight. At this rate we should be seeing it sometime in the 2030s.

640k Was Never Enough For Anyone: How DOS Broke Free

January 21, 2024 by 38 Comments

On modern desktop and laptop computers, there is rarely a need to think about memory. We all have many gigabytes of the stuff, and it’s just there. Our operating system does the heavy lifting of working out what goes where and what needs to be paged to disk, and we just get on with reading Hackaday, that noblest of computing pursuits. This was not always the case though, and for early PCs in particular the limitations of the 8086 processor gave the need for some significant gymnastics in search of an extra few kilobytes. [Julio Merion] has an interesting run-down of the DOS memory map, and how memory expansion happened on computers physically unable to see much of it.

The 8086 has a 20-bit address bus, giving it access to a maximum of 1 megabyte. When IBM made the PC they needed space for the BIOS, the display, and the various accessory ROMs intended to come with expansion cards. Thus they allocated a maximum 640k of the map for RAM, and many early machines shipped with much less than that. The quote from Bill Gates about 640k being enough for anyone is probably apocryphal, but it was pretty clear as the 1980s wore on that more would be needed. The post goes into how memory expansion worked, with a 64k page mapped to switchable RAM on a card, and touches on how DOS managed extended memory above 1 Mb on the later processors that supported it. We dimly remember there also being a device driver that would map the unused graphics memory as EMS when the graphics card was running in text mode, but such horrors are best left behind.

Of course, some of the tricks to boost RAM were nothing but snake oil.

8086 header: Thomas Nguyen, CC BY-SA 4.0