INT21 0x5D full implementation

[Yogi-baer]

Hi,

I am using DOSBox-X on a Raspberry Pi 4 to run Windows for Workgroups 3.11 to have an IPX-Server offering an IPX-Share.

• It is running inclusive share

• Any access to the share is failing
  Error: DOSMISC:DOS INT21H function 0x5D subfunction 0x00 not implemented

1. I volunteer for the implementation
2. I am lacking any documentation of the function 0x5D

Is anybody able to support me with a detailed documentation of the function 0x5D?

BR Yogi-baer
P.S.: No misspelling, just the German writing :-)

[rderooy]

Int21 function 5D are file sharing functions for networking. Maybe an issue with SHARE?

e.g.
http://osfree.org/doku/en:docs:dos:api:int21:5d

But it does not mention a subfunction 00.

[joncampbell123]

Ralph Brown saves the day as usual :) http://www.ctyme.com/intr/rb-3017.htm

[Yogi-baer]

Hey rderooy,

thank you for your response.

I am sure that it is an issue with SHARE. And it does mention a subfunction 00:
https://stanislavs.org/helppc/int_21-5d.html
But this documentation is not helpful for implementation. Therefor I am looking for a more detailed one.
Perhaps someone is having the "DOS Programmers Reference" version 5.

BR Yogi-baer

[Yogi-baer]

Ralph Brown saves the day as usual :) http://www.ctyme.com/intr/rb-3017.htm

I am on it ...

[Yogi-baer]

Hey joncampbell123,

your link is helpful, but I have to think about it a little longer.
I guess it will be a good idea to disassemble an original MS-DOS to get a hint, how to implement this subfunction.
I will come back in a few days ...
It's been a while since I worked with DOS the last time. ;-)

BR Yogi-baer

[ThomasKjoernes]

You don't have to disassemble anything, the source code for MS-DOS 6 is out there and ah=5D can be found inside dos\srvcall.asm

[Yogi-baer]

Hi Thomas,

thanks for your hint. Unfortunately you offered a relative link where I cannot spot the location to look at. The file "srvcall.asm" is not part of this project.
Wlth the filename "srvcall.asm" I did not find anything usable on the internet, I kindly ask you for a full qualified link.

BR Yogi-baer

[ThomasKjoernes]

You will have to find the source code yourself. DOS 1.x, 2.0, 3.3 and 6.x is all out there. Just google it. Alterantively FreeDOS will most likely also have an implemention that is a good reference. "srvcall.asm" is the name inside the DOS source code.

[Yogi-baer]

I am still active on this issue.
I did not find any source code for this undocumented function of MS-DOS.
Debuggers like CodeView don't step into INT21h.
I did not find THE point inside DOSBox-X to trace an installed MS-DOS 6.22.
So I started to write a DOS-Programm (MASM 6.0A) to dig deeper into this on a physical PC (Pentium with physical RS232) with debug output via INT14h.
So far it is working, but it still takes time to get forward.
I am open for suggestions, how to speed up.