I've tried googling and searching FPC mailing list for information about this one, but I found nothing. I just found in http://www.delorie.com/djgpp/v2faq/faq3_1.html that DJGPP requires MS-DOS version 3.1 or later.

Would someone here tell me exactly about lowest MS-DOS version supported by FPC?

Bihar Anwar

3.1, I'm pretty sure. AFAIK it doesn't use any specific DOS 5.x+ calls except perhaps for checking for existence of DOS 7.x (Win95) LFN functions. And DOS 4.x was close to non-existent anyway.

Of course, it has probably never tried with such old versions.

Vinzent.

Thank you very much Vinzent.

In general, FPC compiled programs (and the compiler itself with some limitations) should hopefully work correctly under DOS 3.1+ as specified for DJGPP. Some functionality would not work properly without having at least MS DOS 3.3+ (increasing of default count of file handles used in unit system, checking of country information used in SysUtils). However, I don't think that anyone tried it with anything older than MS-DOS 5.0 recently. If you really need to use an even older version (why?) and if you encounter difficulties with FPC compiled programs running under such an old version, let me know, I may try to have a look at it (I'm not completely sure if I still have access to anything older than MS-DOS 4.01 though).

Note that requirements are different for building RTL and packages for the GO32v2 target (rather than just using compiled units from a release or a snapshot). In particular, support for long file names (as available in MS DOS v7.x or also provided by some TSR utilities) is necessary for using FPC makefiles to build FPC from provided source files.

Tomas

PM wrote

However, I don't think that anyone tried it with anything older than MS-DOS 5.0 recently.

So, the safe assumption is fpc-compiled programs should run smoothly in at least MS-DOS 5.0. Thanks for the info.

If you really need to use an even older version (why?)

No, I won't use such old MS-DOS version, but it always good to let users know the minimum requirements.

if you encounter difficulties with FPC compiled programs running under such an old version, let me know, I may try to have a look at it (I'm not completely sure if I still have access to anything older than MS-DOS 4.01though).

Actually, I've been creating cross-platform libraries for my future programs. For MS-DOS, I will test the libraries in MS-DOS 5.0 as you suggest, and I will report any anomaly I find here or through the bug tracker. Thanks Thomas for your valuable time.