Building MS-DOS from Source Code
So, recently I found the source code of MS-DOS 1.25, 2.0 and 4.0 hanging around on github: https://github.com/microsoft/MS-DOS
And I was wondering, is it possible to build the source code right and be able to use it on a Classic x86 PC? I mean, if Microsoft can do it, I can do it.
I Know that MS-DOS is written in x86 Assembly and in later versions, in C and Assembly.
Summary of checking MS-DOS 1.25 Source Code:
Fully written in x86 assembly, I Found some files written in Basic and as a MS-DOS Executable (.com), however those are likely the programs used by the user.
Summary of checking MS-DOS 2.0 Source code:
Weirdly, there is not just assembly in 2.0 Source code, but some ones that I don't know, BAS (Basic) can be found, but then there's 2 OVRs. I Found one HLP File, and weirdly a file with no extension: simply "COMLINK"
Summary of checking MS-DOS 4.0 Source code:
There is a giant variety of files & extensions, but it is normal for such a OS.
Also I found a batch file for building MS-DOS 4.0, which is something 1.25 and 2.0 don't have, I'll try to build 4.0 first since theres a batch that says the instructions to build 4.0.
Also, the batch says that the NMAKE utility is used, which is something I can't find in the source code as an executable.
NMaker is a Make system for MS-DOS And Modern Windows versions, but it doesn't specify MS-DOS 4.0 as supported.
I Think MS-DOS needs to be installed first to build 4.0, since batch is only executable on windows or MS-DOS.
And I was wondering, is it possible to build the source code right and be able to use it on a Classic x86 PC? I mean, if Microsoft can do it, I can do it.
I Know that MS-DOS is written in x86 Assembly and in later versions, in C and Assembly.
Summary of checking MS-DOS 1.25 Source Code:
Fully written in x86 assembly, I Found some files written in Basic and as a MS-DOS Executable (.com), however those are likely the programs used by the user.
Summary of checking MS-DOS 2.0 Source code:
Weirdly, there is not just assembly in 2.0 Source code, but some ones that I don't know, BAS (Basic) can be found, but then there's 2 OVRs. I Found one HLP File, and weirdly a file with no extension: simply "COMLINK"
Summary of checking MS-DOS 4.0 Source code:
There is a giant variety of files & extensions, but it is normal for such a OS.
Also I found a batch file for building MS-DOS 4.0, which is something 1.25 and 2.0 don't have, I'll try to build 4.0 first since theres a batch that says the instructions to build 4.0.
Also, the batch says that the NMAKE utility is used, which is something I can't find in the source code as an executable.
NMaker is a Make system for MS-DOS And Modern Windows versions, but it doesn't specify MS-DOS 4.0 as supported.
I Think MS-DOS needs to be installed first to build 4.0, since batch is only executable on windows or MS-DOS.
Comments
See:
https://www.os2museum.com/wp/dos-2-11-from-scratch/