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.
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
I used DR-Dos. I remember when an updated windows came out, it wouldn’t install until after DR-Dos patched it.
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.
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 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
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???