MS-DOS (MicroSoft Disk Operating System) was without a doubt one of the most pivotal operating systems back in the 80s and early 90s, with the very same operating system paving the way in user base and popularity into what we now know as Microsoft Windows, with MS-DOS even being included into initial releases of Windows 95, and still being supported up to the year 2000, with the final releases being alongside Windows ME.

Given the importance of the operating system in computer history, Microsoft originally released the source code for versions v1.25 and v2.0 of MS-DOS to their GitHub repository, making them open source, back in 2018, which according to Microsoft it was mainly done for education and experimentation for low-lever software programmers.

In April 25th, 2024, Microsoft has released yet another version of MS-DOS into their public repository, with the latest version to be included and publicly available being v4.0.

The current open source repository for MS-DOS works under the MIT license, and has been archived and marked for historical reference, so Microsoft will not accept any kind of pull requests nor modifications to the files on their repository, but users are able to fork the open source MS-DOS project and experiment on their own.

MS-DOS still has newer versions yet to become open source, since it goes all the way up to version v7.0 for Windows 95, and the last version known being v8.0 releases alongside WIndows ME, but until Microsoft decides, versions v5.0 up to v8.0 still remain as closed source.

Source

 

[J-Will]

Nice! I'll make sure to check this out.

 

[Noctosphere]

Very nice of them to release an obsolete code

 

[RAHelllord]

Very nice of them to release an obsolete code

Obsolete but potentially still useful to the fine folks at DosBox and similar emulators. There are plenty of old games for MS DOS that are still worth playing today.

 

[tech3475]

I hope they get around to 6.22 at some point, especially if it improves Win 3.11 support on FreeDOS, etc.

Very nice of them to release an obsolete code

Would you prefer it if they kept it closed source?

Obsolete but potentially still useful to the fine folks at DosBox and similar emulators. There are plenty of old games for MS DOS that are still worth playing today.

There's also still people who mess around with 8088 based hardware, so potentially still useful for tinkering.

 

[AndorfRequissa]

with the advancement of AI MS-dos looks like a more competient OS than the spyware based OS that most people use.

 

[Latiodile]

I hope they get around to 6.22 at some point, especially if it improves Win 3.11 support on FreeDOS, etc.

considering it took them 10 years to release anything newer than 1.25 and 2.0, we'll be waiting a good 10-20 years before they release 6.22, or even 5.0

 

[The Real Jdbye]

Obviously this code is useless nowadays, but it's pretty cool to be able to look at the source code of a piece of history.
I wonder if there are any funny comments. Might have a look myself.

 

[osaka35]

Any opensourcing is a good thing. Good day

 

[Deleted member 698398]

It's noticeably missing the source code for the multitasking extension MSDOS 4 had.

 

[Flame]

Now I need to go back in time with this code. then I can become rich!

To the Batmobile Old Bessie.

 

[Jayro]

considering it took them 10 years to release anything newer than 1.25 and 2.0, we'll be waiting a good 10-20 years before they release 6.22, or even 5.0

Is there anything in 6.22 that FreeDOS can't do?

 

[Latiodile]

Is there anything in 6.22 that FreeDOS can't do?

a lot of games don't run on it afaik, or are buggy/broken

idk i don't mess with dos era stuff, but i know that freedos isn't perfect

 

[Jayro]

Hmm, okay. I haven't had any issues personally with FreeDOS, but I primarily stick to id Software's games.

 

[HarveyHouston]

Could help in further DOSBox emulation.

 

[Xdqwerty]

If i had a nickel everytime the source code of something related to ms dos got released i'd have two nickels. Which isn't a lot, but it's weird that it happened twice.

Spoiler

The first one is Doom

 

[tech3475]

Is there anything in 6.22 that FreeDOS can't do?

Off the top of my head, last I looked it doesn't support 386 enhanced mode on Windows 3.11.

May not be necessary but I like having it and occasionally use the odd piece of software on it.

 

[Latiodile]

If i had a nickel everytime the source code of something related to ms dos got released i'd have two nickels. Which isn't a lot, but it's weird that it happened twice.

Spoiler

The first one is Doom

the source code for doom, quake, dos 1.25 and 2.0 are available, it happened more than twice lol
you failed at this meme

 

[linuxares]

the source code for doom, quake, dos 1.25 and 2.0 are available, it happened more than twice lol
you failed at this meme

I'm honestly surprised how many games ID and Raven Software have made Opensource.

https://en.wikipedia.org/wiki/List_of_commercial_video_games_with_later_released_source_code

 

[SylverReZ]

Be careful when downloading from Microsoft source repositories. Recently, bad actors are pushing malware via legitimate looking Microsoft repo URLs, making them seem trustworthy.

https://www.bleepingcomputer.com/ne...used-to-push-malware-via-microsoft-repo-urls/