Hi, I got bored (despite already knowing about this history), so I started watching Nostalgia Nerd's video on "AARD" (re: Win 3.1 beta atop DR-DOS) on YouTube.
"Windows’ Hidden Self Destruct Code | Nostalgia Nerd" * https://youtu.be/TIfNIWn2Ad4?t=753 (comments further below) On Wed, Feb 22, 2023 at 3:20 PM Aitor Santamaría <aitor...@gmail.com> wrote: > > Well, thanks to all that contributed to this interesting topic (there are > quite a few interesting mails in the thread). > > I could find very little extra information, like this: > > https://www.os2museum.com/wp/dos/dos-4-0/ > > Also I found references on IFSFUNC: in 2Fh (AH=11h), IFSFUNC functions seem > to be entangled with the network redirector functions: > > http://www.ctyme.com/intr/int-2f.htm > > Apparently, these functions would be made available by IFSFUNC.EXE (curiously > not provided by kernel itself). > So I suppose the current only way to know more would be to acquire a MS-DOS > (or IBM-DOS) 4.0, disassemble this file. > > My conclusion would be that it looks like an alternative functionality update > to the network redirector itself (and not something entirely unrelated), that > tried to solve some of the previous problems and/or tried to be more abstract > and less tied to internal DOS structures, that was implemented only in DOS > 4.0, probably to try and make HPFS available for DOS, but that was later > abandoned (due probably to high memory requirements) in favour of maintaining > the old redirector). I'm not sure where this pseudo-code came from (Geoff Chappell?). But this is what the above video mentions (12:33 in): IF redirector running (INT 2Fh AX=1100h) AND IF default upper-case map (INT 21h AX=38h) in DOS data segment (INT 2Fh AX=1203h) OR IF no redirector AND IF FCB-SFT header at paragraph-boundary (offset == 0) THEN DOS is considered okay Just wanted you to know. (Yes, it's mostly irrelevant.) _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
