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The current open source repository for MS-DOS works under the MIT license, and has been archived and marked for historical reference, so Microsoft will not accept any kind of pull requests nor modifications to the files on their repository, but users are able to fork the open source MS-DOS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

 

[DTApple]

Wicked!

 

[Latiodile]

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

that list is a lot longer than i thought it'd be, i'm surprised that amnesia is on there

 

[linuxares]

that list is a lot longer than i thought it'd be, i'm surprised that amnesia is on there

Yeah! Actually a lot of newer games even on it... I'm surprised as well!

 

[Battleboy96]

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.

Like DOOM

 

[romanaOne]

My first DOS was 3.something and I think it was burned into the BIOS ROM of the shitty Tandy-1000 286 my clueless-about-computers parents bought me around 1990. Somehow, even after upgrading to an already-obsolete 386 in 1992, I missed DOS 4: the cheap-ass $800 Wang EXEC 386 I got came with DOS 5 and windows 3.0.

Change in those days was crazy fast compared to the stagnant rot we suffer from now: I guess everyone depending on fucking computers for everything has led to a fair bit of inertia. In any case, does anyone who was there know if there was anything wrong with DOS 4? I don't think I ever even saw it on any friends' PCs and have a vague recollection that people thought it sucked at the time.....

 

[DuoForce]

although I have no interest in MS-DOS, this is fantastic for those that are into Retro OS

 

[urbanman2004]

I guess it's better late than never. Game History Preservation FTW...

 

[SDA]

Hey, this is some pretty good news actually! I know DOS emulation and games quite well.

 

[cluesagi]

Rare Microsoft W

 

[a_username_that_isnt_cool]

Rare Microsoft W

its cause it's the oldest os microsoft made (that i can think of)

 

[tech3475]

its cause it's the oldest os microsoft made (that i can think of)

I presume you mean DOS in general and not DOS 4.0

But MS's earliest 'OS' was actually BASIC for the Altair 8800 and from what I can gather in 1980 they released a UNIX variant called Xenix, predating DOS by about a year.

That said, DOS 1 was essentially just a rebranded QDOS from what I've read, so semantics could be argued as to whether it counts as an OS MS 'made'.

 

[subcon959]

I don't really remember 4.0, but 5.0 was when I made the jump to a beefy PC. I wish I still had that machine:

486DX33
8 MB RAM
1 MB Trident GPU
Soundblaster v2.0
100 MB HDD

Good times.

 

[Ryccardo]

does anyone who was there know if there was anything wrong with DOS 4? I don't think I ever even saw it on any friends' PCs and have a vague recollection that people thought it sucked at the time.....

That's because there are 2 operating systems called MS-DOS 4...

One is the successor of DOS 3.31 and it's fine, just unremarkable (uses more RAM by default, most significant innovation in the kernel is modern-definition-of-FAT16 up to 2 GB - in 3.30 it was 32 MB which for the time was still somewhat premium, and a half GB in 3.31 that almost nobody had - , most significant added program is dosshell)

The other is a complete reimplementation with multitasking - a disaster that few even got close to trying (while of course an "IBM compatible" version worked on any PC, DOS was only sold in OEM versions until 5, and maybe 3 computer companies in the world stocked this edition)