Microsoft Open-Sources MS-DOS 4.0 Under MIT License

[kpedersen]

The source code that was released is for the extremely unique Multitasking MS DOS 4, NOT the mainstream PC DOS / MS-DOS 4. So it may not be missing, it may not have been there to begin with.

I have only looked at the GitHub so far but I believe it is the other way round. The source was for MS-DOS 4.0 but as a bonus they found disk images for Multitasking DOS (beta) which is in the repo as 4.x-ozzie (albeit no source code for that).

[kpedersen]

DOSBox (the original one) is dead and does not work too well on current systems anymore.

DOSBox 0.74-3 is pretty much complete (thus no releases for a while and subversion is pretty static). Seems to work well on all current platforms I have tried. Unless you want i.e Windows 98 (outside the scope of upstream DOSBox), it is good. Even SDL 1.2-compat works with it.

And both DOSBox-X and DOSBox Staging are far from being complete, you can believe me. Just look at the issues reported on the GitHub .

Those projects aren't complete, nor will they ever be. The intention for them is to try to encompass everything in true open-source fashion

[Nocturnal64]

DOSBox 0.74-3 is pretty much complete (no releases for a while and subversion is pretty static). Seems to work well on all current platforms I have tried

The last time I tried, I only got a black screen on Linux. It did work on Windows 11, but switching it to fullscreen took like 5 seconds.

By being far from complete, I mean a lot of important hardware is still not emulated (or emulated just partially), a lot of APIs or DOS commands not implemented (for example, DOSBox Staging misses SHARE support, for which there is now a source code available), etc. VICE or WinUAE are in much better shape.

[chithanh]

It makes you wonder what ancient gold other veterans have squirreled away on rotting disks in the attic! Please, everyone, release the code if you no longer plan to do anything commercial with it!

Windows Longhorn
Trident
KIN

Indeed. Actually using it, MS-DOS 6 was better (mainly because more software was available for it IMO). I imagine Microsoft isn't releasing it yet because there are still some very niche areas (very much legacy) that still use 6.x. But this is shrinking and I am sure Microsoft will release it at some point.

but the only relevant dos version is 6.22

I think (but could be mistaken) that MS-DOS 6.x cannot be easily released as open source, because it contains compression technology from Stac - with the exception of MS-DOS 6.21 where this was removed due to the litigation between Stac and Microsoft.

[mxan]

If IBM and M$ are willing to team up for releasing MS-DOS's source, then why not for OS/2?

[bezirg]

After open-sourcing Paint and Windows Calculator, we have another tremendous contribution of MS to the open-source community. MS <3 opensource </sarcasm>

At this rate, we may see the open-sourcing of MS Minesweeper before the turn of this century.

[qarium]

I doubt it very much, Dosbox is already way ahead of this. MS doesn't open source anything until its worthless. The worth to them is just saying they did.

right for microsoft this is a pure PR stunt... its just so that articles pop up on google news and people can read microsoft do open-source to...

[Rccero]

I wonder if the code will be useful for Dosbox and FreeDOS.
FreeDOS has inaccuracies in some of its drivers that might cause compatibility issues (I think its CDROM driver was the worst offender).

Even if it's useless for them, I think opensourcing MSDOS is positive just for preservation of an ancient part of PC history.

[sophisticles]

This is a great development and many thanks to Microsoft.

Now Linux developers can look at how a real OS is coded and improve their half-assed product by 500%.

Hopefully MS will release the source code for Windows 1 under an MIT license and Gnome can have its usability improved by a few generations.

[Daktyl198]

Can ReactOS perhaps benefit from this in some way?

No. ReactOS is based on the early NT kernels, not DOS.