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Microsoft open sources MS-DOS 4.0

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More open source surprises for you today, coming from Microsoft too which is always interesting to see as they've now open sourced MS-DOS 4.0.

Added into their existing MS-DOS repository on GitHub which already had MS-DOS v1.25 and v2.0, they've now expanded it to include MS-DOS v4.0 which was jointly developed by IBM and Microsoft. This is all available under the permissive MIT license.

From the repo:

The MS-DOS v1.25 and v2.0 files were originally shared at the Computer History Museum on March 25th, 2014 and are being (re)published in this repo to make them easier to find, reference-to in external writing and works, and to allow exploration and experimentation for those interested in early PC Operating Systems.

They're doing this for "historical reference and will be kept static" so they're not accepting pull requests, but that doesn't stop someone forking them and doing pretty much whatever they want now it's all under the MIT license. Great news for preservation.

It will be interesting to see if they eventually keep going adding in more later versions, and perhaps even get some earlier versions of Windows up too. Now that would truly be something don't you think?

There's a fun little tidbit of history in the Microsoft blog post on it with the code being found on some old floppy disks.

Article taken from GamingOnLinux.com.
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19 comments
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elmapul Apr 26
i bet they did that because wine/dosbox already can run 100% of dos 4.0 games/softwares, so it would be useless to keep this codebase proprietary anyway and by open sourcing it they create an good image for thenselves.
Eike Apr 26
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Quoting: elmapuli bet they did that because wine/dosbox already can run 100% of dos 4.0 games/softwares, so it would be useless to keep this codebase proprietary anyway and by open sourcing it they create an good image for thenselves.

And if DOSBox wouldn't run the games? They'd sell MSDOS 4.0?
elmapul Apr 26
Quoting: Eike
Quoting: elmapuli bet they did that because wine/dosbox already can run 100% of dos 4.0 games/softwares, so it would be useless to keep this codebase proprietary anyway and by open sourcing it they create an good image for thenselves.

And if DOSBox wouldn't run the games? They'd sell MSDOS 4.0?

if dosbox cant run, probably the game was made for MSDOS 5.0, 6.0 or something like that.

that is exactly what im saying, if the full scope of an tech is already supported by an open source alternative, there is no reason to keep the secret an secret anymore.
Eike Apr 26
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Quoting: elmapul
Quoting: Eike
Quoting: elmapuli bet they did that because wine/dosbox already can run 100% of dos 4.0 games/softwares, so it would be useless to keep this codebase proprietary anyway and by open sourcing it they create an good image for thenselves.

And if DOSBox wouldn't run the games? They'd sell MSDOS 4.0?

if dosbox cant run, probably the game was made for MSDOS 5.0, 6.0 or something like that.

that is exactly what im saying, if the full scope of an tech is already supported by an open source alternative, there is no reason to keep the secret an secret anymore.

If it wouldn't be supported by an open source alternative, there would be no reason to keep the secret a secret anymore either. It's not like they would make money from MSDOS 4.0 anyway.
Solarwing Apr 27
Well this is the beginning of the end for M$! A new good era awaits us! Tux is raised to a fight against the all the evil that M$ with their henchmen(Windows 95,98,ME,2000,XP,8,10,11) have done. Soon the Tux will vanquish M$ for good by wielding Excalibur, which SHE has borrowed from Merlin- only temporarily ofc! And then we will be guided by good hand of Tux forever! Long live the new Queen! Now back from the future to the current time. I mean this is interesting. I hope they would open up Dos 6.22 soon. And why not Windows 95? That would be something!
jarhead_h Apr 28
Bryan Lunduke - Microsoft Releases DOS 4.0 Source Code... but it Doesn't Compile!





https://www.youtube.com/watch?v=pzhGAt3wYTI
hardpenguin Apr 29
Quoting: lucinosWe already have FreeDOS so MS-DOS is only for history. It would be more interesting to release Windows 3.1 as open source. This might actually happen. Also very interesting would be the release of windows 95. This unfortunately is very unlikely as I remember they have many legal complications. The last windows version I would care is windows 2000. After 2000 I would just prefer windows to simply vanish from existence.
Agreed, they should open source at least the over 20-yo Windows XP. Too little too late, we now have extremely matured DOSBox and Wine that cover nearly all of our needs.
Jahimself May 1
QuoteAgreed, they should open source at least the over 20-yo Windows XP
Hehe XP still recent enough to the point that an open sourced version, would take like two weeks before it could run anymodern or old software & game faster than any modern windows.
osyx May 2
Quoting: SolarwingWell this is the beginning of the end for M$! A new good era awaits us! Tux is raised to a fight against the all the evil that M$ with their henchmen(Windows 95,98,ME,2000,XP,8,10,11) have done. Soon the Tux will vanquish M$ for good by wielding Excalibur, which SHE has borrowed from Merlin- only temporarily ofc! And then we will be guided by good hand of Tux forever! Long live the new Queen! Now back from the future to the current time. I mean this is interesting. I hope they would open up Dos 6.22 soon. And why not Windows 95? That would be something!

I find it highly unlikely that they would release Win 95+ given how much of Windows that is still based on top of it. They really don't seem like the type of company to open source their main product, as much as they want to be seen as it, without actually doing it.
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