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.
It didn’t go to medical school to be called MR-DOS
Hehe :-)
FreeDOS has been able to run Windows 3.1 since 2021
As noted by El Reg:
I ran DR-DOS briefly and would have liked to continue running it because it was faster than MSDOS. Alas, DR-DOS was incompatible with Microsoft’s networking program.
I wrote this Register article and supported DR DOS in production. No, it wasn’t. :-)
But this is what I was getting at: while you can get, say, Windows 3.1 working on both of them, it requires a level of tweaking that’s beyond most people so long after it was current.
And even before this, when using Standard-Mode kernal (win /s or win/2).
Merely 386 Enhanced-Mode kernal (win /3) had required a special FreeDOS kernal in the not so distant past.
“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”
Isn’t that the “european” multitasking DOS from mid-80s, the proto-OS/2, that pre-dates PC-/MS-DOS 3.x?
PC-/MS-DOS 4 from 1988 was a different beast, I think.
Anyway, an even more interesting open source “DOS” is PC-MOS/386 v5.
It’s like a DOS version of MP/M and has DOS 5 ABI compatibility.
MOS can run multiple DOS programs on virtual screens and serial terminals.
You have consoles like on *nix and Linux, in short.
Very interesting for tinkerers.
https://github.com/roelandjansen/pcmos386v501
Sadly, no. They only found binaries for that, I believe.
MS-DOS 4.0 ( with multitasking) has been fully open-sourced! Microsoft, in partnership with IBM, released the source code for MS-DOS 4.0 under the MIT license in April 202412. This release includes the source code, binaries, and documentation
https://github.com/microsoft/MS-DOS/tree/main/v4.0-ozzie
So…
We’ll have to wait 19988 years for it?
I used DR-Dos. I remember when an updated windows came out, it wouldn’t install until after DR-Dos patched it.
I refer to that in the Reg article, with links.
https://www.geoffchappell.com/notes/windows/archive/aard/index.htm
DR-DOS worked pretty well for booting into NetWare if you didn’t want to have any Microsoft products on your server. It was only little less expensive than MS-DOS and either boot O/S was a tiny fraction of the cost of the NetWare license anyway.
I wouldn’t recommend DOS 4.0 on my worst enemy. More unstable than Humpty Dumpty on a wall.
Humpty Dumpty is very stable and predictable. It always falls.
I used DR-DOS at work in the years around 1990, and liked it. It looks like the last archive of the now-gone website is at https://web.archive.org/web/20180324142157/http://drdos.com/products/dr-dos/ . I think DR-DOX and FreeDOS are supposed to be multitasking. I will be looking into SvarDOS though. Today I still do a few things in DOS, but since my last previous DOS machine went down and I can’t find one now that has the right kind of slots for my EPROM programmer, I’ve had to buy a USB-interfaced one and run all my DOS stuff on this Linux PC using the DOSbox-X DOS emulator. I’m still fighting to try to get some sort of native-like RS-232 support, as the FTDI adapter’s software driver makes it very clumsy. There are some ways in which all these advances are not really improvements. It is nice however that last year (2023 IIRC), DOSbox was dramatically improved in many, many ways, bringing us DOSbox-X. Whoever wrote DOSbox seemed to think it was only going to be used for old games. Games don’t belong on my computer though.
The DOSbox team isn’t exactly anonymous, and yes, the original intention was primarily to run DOS games, hence the name in the first place – it was something of a reference to what gamers would call the command-line prompt in Windows. Even old people can still do their homework, you know.
“Games don’t belong on my computer,” I pity you, you sound like a real fun person to be around (/s).
“I pity you, you sound like a real fun person to be around”
I’ve always had more hobbies and interests than almost anyone people I knew. There are too many fun and interesting and productive things in life to have any time for TV (which I haven’t watched a single minute of in years) or games which are a total waste of time. My voluminous website shows just a few of my interests.
Would QEMU work for your needs? With any of the DOS options.
I haven’t heard of it until now. I need to look into it.
The problems in using DR DOS are long, and having used it myself for both personal and business I routinely ran across so many problems I had to give up on it. The most stable DOS was MS DOS 4.01. the most useless DOS was MS DOS 2.0/2.1. The best DOS was MS DOS 6.22. But many programs would routinely not run properly or at all in some cases using specific versions of DOS. PC and MS were pretty to each other and compatible with most programs, but DR wasn’t, hence the very minute install base it had.
MS-DOS 2 (2.11) was not “useless”, I think.
It was a rewite and had introduced directories, common DOS devices and Unix features.
MS-DOS 2.x allowed using both / and \ separators, for example.
There’s an undocumented command to switch to Unix paradigm, which was removed in DOS 3.
Info: https://www.youtube.com/watch?v=Vo8NG8T4rWs
DOS 2.x was very small, also. It did take up about a tiny 24 KB of RAM and ran on old IBM PCs with little RAM (64 to 128 KB).
It was very limited (360KB drives at max), but had the basics.
Then there was DOS Plus, a variant of CP/M‐86 that could run both CP/M-86 and MS-DOS applications.
It was bundled with the famous Amstrad/Schneider PC1512 (and 1640).
This PC was like Europe’s answer to the Tandy 1000, maybe.
IBM’s PC-DOS 3.30 then was the next big thing, I think.
It added featured support for the modern technology as we know it.
AT realtime clock, 1,44 MB floppy drives, FAT16, multiple partitions (logical drives).
It was still small enough to be used on an XT without HDD.
And it was probably the most “generic” version of DOS, so it worked fine with clones.
Other DOSes were still OEM versions with their own utilities.
Compaq DOS 3.31 cones to mind, which had support for bigger HDD partitions (512MB).
By late 80s, there also was Wendin DOS, which was an early multitasking DOS, like PC-MOS/386 (or Concurrent DOS 386).
Both could use the MMU of the 80386 CPU to enhance multitasking and provide more memory (years before EMM386 and QEMM got popular).
DR-DOS 5 then was important because it added support for HMA and UMBs.
It had a GUI named ViewMax, which was a cutdown GEM 3.
DR-DOS was so good that Microsoft was forced to released MS-DOS 5.
And thanks to that, we finally got our all time classic, MS-DOS 6.2x.
About DOS 4.x from 1988/1989..
Many consider it to be the equivalent to Windows Me or Vista.
It was a memory hog, but it also added things like FAT16B (Big DOS) and an installable filesystem (IFS).
Unfortunately, it was a dead end. MS-DOS 5 returned to MS-DOS 3 code base.
That’s why Windows 2.x has issues with DOS 5 and 6.x, by the way!
It checks version number and falsely assumes they’re both using MS-DOS 4 kernal structures!
Using SETVER or faking DOS 3.30 version number manually makes Windows 2 run on newer DOSes just fine.
Other notable DOSes were Datalight ROM DOS, Novell DOS 7 (small, with networking and Windows 3 software), PTS/Paragon DOS.
And soviet DOSes like AlphaDOS, Sigma Four DOS and Disc Control Program (DCP, East Germany).
More information:
https://en.wikipedia.org/wiki/Timeline_of_DOS_operating_systems
Do you know if you can still get access to those Iron Curtin doses? I’m sure the complex politics and copyrights would mean you could use them as the basis for new open source doses.
Hi, these old-dos ru things can be found on the web.
You’ll have to use a search engine, though.
DCP 3.30 by Robotron for EC1834 PC model was mostly IBM PC compatible, for example.
Sigma Four DOS, MDOS and DCP and others were used for the little Poisk-1 home computer, I think.
AlphaDOS was the DOS rather used by the gov., I think.
It used a custom character set on PCs (ES1840 etc) that were “built like tanks”. Later USSR DOSes used code page 866.
Paragon/PTS DOS was military grade and sold in 90s Germany and in other places.
With exception of PTS/Paragon DOS they were all rather old, though.
About MS-DOS 3.x level, I think. Still usable, but darn old to MS-DOS 6.2 users.
Finding source code might be tricky, maybe.
Back then, assembler/disassembler were often used to modify things.
PTS/Paragon DOS has best chance to have complete source code available, I think.
And DR DOS 3.41 was their best release.
“I’m still fighting to try to get some sort of native-like RS-232 support, as the FTDI adapter’s software driver makes it very clumsy. ”
There are also USB serial converters with PL-2303..
Anyway, one issue that sometimes happens the frame issue/5-Bit issue.
You can try Qemu as an emulator fir running DOS instead.
A standard installation of MS-DOS 6.22 without any V86 memory managers should work troublefree, at least.
Things like UMBPCI.SYS, UMBM.EXE, MAXMEM.SYS (MAXMEM package) and DOSDATA.SYS, DOS-UP.SYS (Qemm) and other memory utilities can be used, I think.
They’re Real-Mode DOS friendly. An environment that doesn’t cause timing issues.
“Whoever wrote DOSbox seemed to think it was only going to be used for old games. Games don’t belong on my computer though.”
That’s the official policy of the author and its understandable.
It’s not about being capable or not, but rather about the fact that DOSBox does take a lot of shortcuts in emulation to provide best performance for games.
If DOSBox then would be used for say, an accountic software, the records might be all wrong because x87 emulation might be inaccurate (rounding issues).
Or worse, imagine the timer emulation wasn’t good enough for a medical software.
That’s why the developers made it clear that the official DOSBox is for games only. They weren’t unaware about DOSBox’ capabilities. Just wise.
Can we get a little love for GemOS. Came out and was popular around the time that DR-DOS was looking promising. Had WFW 3.11 not been stable and received rapid evolution, we might be singing the praise of GEM-OS or forgive me, OS/2.
To all our steps big and small, let us tip our heads for a moment and fondly remember.
Steve Gibson!!! Why have you forsaken us all???
You mean GEM by Digital Research? If so, it wasn’t unpopular.
GEM had been shipped with Atari PCs (PC1 to 5), the BBC Master 512, the Amstrad/Schneider PC1512 (and 1640)
and other lesser known PCs, such as Siemens PC-D, I think.
The primary applications GEM Paint, GEM Draw and GEM Write were analogs to MacPaint, MacDraw and MacWrite. ;)
Other applications were Locomotive Basic, as well as:
GEM WordChart
GEM Graph
GEM 1st Word Plus
GEM Desktop Publisher
GEM Programmer’s Toolkit
GEM WordChart
Then there were other applications based on GEM:
Ventura Publisher, Artline, Publish-It, Key Publisher
Exploring A 1988 Atari PC & The GEM Desktop:
https://www.youtube.com/watch?v=rJ_xxvUW77Y
That being said, GEM wasn’t as great as some peoplemake it sound.
It had quite some limitations over MS Windows 2.x.
For example, GEM didn’t allow multitasking.
Applications were full screen, with a maximum of 6 (?) windows on screen.
Windows of a single program, I mean. Locomotive Basic gives a good impression of a multi-window screen, I think.
By comparion, Windows 2 line had offered Windows /386 which could provide EMS on a 386 and run multiple DOS programs in a window, each with 640KB of RAM.
Programs could overlap and be run minimized. Like Klotz, the Tetris game.
But even normal Windows 2 had the ability to run well behaved DOS text-mode applications in a window. The memory limitations were severe, though.
Still, playing Zork and running Windows Terminal was possible same time.
So someone could call a mailbox via acoustic coupler and download a file, while playing Zork.
So a Windows vs GEM comparison merely makes sense for Windows 1, I think.
GEM had cool features “under the hood”, though. Font rendering etc.
A real competitor to Windows in early 90s was PC GEOS: GeoWorks Ensemble.
Version 1 was very quick and ran on slow XTs, whereas version 2 was mature enough to be a true Windows 3.0 rival.
GeoWorks had shipped with a full-fledged office software and ran entirely in Real-Mode. Comparable to Windows 3 w/ MS Works, FoxPro, Excel and WinWord.
It featured optional support for XMS and EMS, though so it was making use of ATs and Expanded Memory boards.
It also had its own executable format like GEM and Windows, but the SDK did cost a fortune and required a workstation.
That’s why Windows 3.x was such a big success, by the way.
Microsoft supported free developers and did hand out SDKs and documents.
Windows 3.x was owned by the users, so to say. They had freedom.
GEM and GEOS were all-in-one packages, rather. Good ones, though.
There were third-party compilers like Turbo Pascal for Windows, MS Quick C for Windows, Visual Basic 1.0, Delphi 1, Borland C for Windows and many more.
The shareware applications for Windows 3.x from the 90s do sing a song of it (see sharewere CDs or Hobbes)
The use of external DLLs, libraries, was possible with Windows.
Windows applications could usem. VBX of Visual Basic was popular.
There had been a whole market for VBX DLLs at the time.
Both GEM and PC/GEOS are FOSS now.
https://www.seasip.info/Gem/History/freegem.html
https://github.com/bluewaysw/pcgeos
I study Dos in 1997 at out school and I still very much use it till these days. It’s so useful even in windows 11.
[Original article author here]
Hey, cool — thanks, Jenny!
In probably the only person in the comments that actually used DR-DOS, I’ve had it installed on all my computers back in the day when it was Caldera DR-DOS!
That’s cool! In my home city, Caldera DOS start-up disks were sold at a computer flea market once. It did cost about 5 DM, I think.
We vistors weren’t told that this were home made disks (printed labels) containing the free single-disk demo image from Caldera.
Nope. The sellers didn’t tell. Ah yes, the 90s! :D
I once also bought a disk set of MS-DOS via newspapers ads,
so I have my own originals (we had them in the family, but I wanted my own).
Did cost me 20 DM. When the mail arrived, I got.. three disks with hand written labels in dirty handwriting!
Such a disappointment. Sigh. Did I ask for too much? I would have been happy with real OEM disks, even!
Probably should have sued that person for piracy, but I was too good hearted.
Your comment is amusing, given that Liam Proven, the author of the article on The Register, posted directly above nearly two hours before you. 😁
DR DOS
Digital Reseach DOS
author Gary Kildall (rest in peace)
Interesting for a current software project that the SvarDOS website doesn’t seem to support HTTPS. Or is that by design, in order to support older DOS-based web browsers or the like?
Drdos ran from tom which meant it was ideal for the small computers I usually worked on. Autoexec.bat would be used sometimes for setting things up (if needed) and command.com replaced by the application which needed to run… Brilliant, small and neat, smaller than today’s embedded systems yet it was dos so could be tested on the ‘big computer’ (512k tam and a collosal 32mb hard drive and 6 MHz clock)
Multitasking OSs issues may lead to vendor bankruptcies?
Bug and malware fix attempts lead to never-ending updates and upgrades which cost big dollars?
Single task interactive, incremental compiling/assembling OSs such as fig Forth and Intel MSC BASIC-52 which run gcc c apps are a now-needed software technology? Written in one page of less of code modules by true software engineers.
These single task OSs must run on inexpensive low-power arm m and a, risc-v, … platforms, of course.
There was of course PC DOS, which was IBM’s own product, though it was based on MS DOS.
Yes, up until a specific point. PC-DOS 3.30, for example, was made by IBM and released a couple of months before MS-DOS 3.30.
From circa IBM DOS 5/6 onwards, IBM made its own thing.
For example, IBM included utilities from Central Point Software.
Microsoft bundled utilities from Symantec.
Both groups were rivals.
PC-Tools vs Norton Utilities did separate the user bases, too.
I myself was a PC-Tools and Norton Commander user. On MS-DOS! :D
Always carried drdos 7 around with me in the late 90’s and early 2000’s. Very handy. Especially the disk which could even create linux and ntfs partitions.
Single task fig Forth or Intel MCS BASIC-52 OSs able to load and run Apache and Le Potato servers?
Without multitasking OSs help, of course
I still have a machine running DR-DOS 8. It’s reliable. (Yeah, I’m a dinosaur. My Windows is always at least one version behind.)