OS/2 File by File Replacement - AI Project Experiment

[Martin Iturbide]

Hello

I'm going forward on the idea of trying to open source as much as possible of OS/2 files as an experiment.
I had made some testing with Claude Code AI and produce me some files that works on OS/2, and ArcaOS and it keeps booting.

I'm starting with the easy stuff (low hanging fruit) and start replacing some small DLLs and executable files, and I will be posting the source code and compiled binaries here:
-- https://github.com/OS2World/OS2-API-Replacement-Experiment

I know the following:
- I will go little by little
- The cloning will not be perfect or stable
- I'm using openwatcom compiler when possible since it is open source. 
- I will take what is available online like OSFree, 2ine, OS2Linux, but with the approach to generate OS/2 replacements.
- I do not know exactly the code that is being generated by the AI, I just tell it if it boot or not, or if the broke something.
- Eventually I will get stuck with the complexity.

Long time ago I create a stripped version of OS/2 Warp 4.52 to determine the minium files for it to boot with GUI, Network and sound. I will use those files as template to go first.
-- https://wiki.os2world.com/index.php?title=Required_Replacements

AI help me creating this "Complexity Widget" list with more details:
-- https://wiki.os2world.com/index.php?title=Required_Replacements_-_Claude_Code_Complexity_Widget

It took me some time to organize myself and understand how to use Claude Code as a project. I think that I'm organized now, even that my compilation techniques are very basic and may not be complete profesional. (you might laugh that I have a compile.cmd on each folder , but that's how I organized my self)

I think my Claude Project had learned a good amount of OS/2 development with the IBM DDK, the IBM Toolkit and a set of development books. The first times it produced a lot of compiling errors, but I keep providing it feedback until Claude improved. Mostly I focused now on DLLs and little executables (CPI, GPI and PM), but hopefully I will move later to some drivers and see what happens.

I generated these binaries.
-- https://github.com/OS2World/OS2-API-Replacement-Experiment/releases/download/2026-07-02/Bin_2026-07-02.zip

├───MPTN
│   ├───DLL
│   │       DDNSRES.DLL
│   │
│   └───MSG
│       └───NLS
│               DHCPMRES.DLL
│
└───OS2
    │   CHKDSK.COM
    │   CHKDSK32.EXE
    │   SORT.EXE
    │
    ├───DLL
    │       BDCALL32.DLL
    │       BDIME.DLL
    │       GLOCMRI.DLL
    │       IMP.DLL
    │       PMBIDI.DLL
    │       THAILIB.DLL
    │
    └───SYSTEM
            HARDERR.EXE

If you want to try it out, please remember that this is unstable and use a clone VM or a non critical system.

Regards

[aziz]

Are you using the free version of claude or do you have a paid subscription?

[Martin Iturbide]

Hello

Are you using the free version of claude or do you have a paid subscription?

I started with the free version to see if it can produced something compilable. Now I have the $20 monthly service.

Regards

[Martin Iturbide]

Hello

It is kind of fun, I became the manager and the tester of the AI, while it does all the coding. It even uses me to do testing on OS/2, so it can find ways to fix the errors, like "try this and give me the log", "now to back to this version so I can compare the logs", etc.

I also think this will help me better to document the EDM/2 wiki with more information about some OS/2 files.

Regards

[Martin Iturbide]

Hello

It was fun that the AI taught me about "PMSDMRI.DLL", and help me me out to improve the EDM/2 wiki
- https://www.edm2.com/index.php/PMSDMRI.DLL
It generate me the RC code for Open and Save As.
- https://github.com/OS2World/OS2-API-Replacement-Experiment/tree/main/PM/PMSDMRI
After some compiles and error fixing, (Disable FOC in the ArcaOS VM), the DLL worked with E.EXE.

Regards