DOS ain't dead

GZIPDATE.REX (uses TOUCH) / Tim Paterson / DOS v3 required (Developers)

posted by Rugxulo , Usono, 23.03.2010, 16:59

> > From what I've heard, DOS 3.3 was the
> > most popular until 5 came around (first to have an upgrade version).
> Yes, as a DOS user already at the time Version 5 came out I would agree
> with this. Version 5 was a big leap forward with built in help etc. I
> remember being jealous of a family member when they got it and I was stuck
> with v4.01 !

5.0 was good for EDIT (QBASIC in disguise) and LOADHIGH. However, it came later than DR-DOS, which was better at the time.

> > I think DJGPP apps require DOS 3.
> I strongly suspect this will be the case. Indeed with most programs
> (particularly EXE files) if you do a HEX search for the following byte
> sequence B430CD21 - the DOS version check:
>
> mov ah, 30h
> int 21h
>
> you will usually note that most programs (due often to their run-time
> libraries) are checking for version 3 or above.
>
> Why the difference on such a simple program?

DOS 2 was too primitive, e.g. argv[0] wasn't stored, some APIs were slightly different (e.g. country stuff, TOUCH uses int 21h,38h ... I thought NLS info wasn't present until 3.3, but apparently they had some very minimal support previously).

> Yes, it depends on your hardware. I have some boxes where early versions
> of DOS boots from silicon and booting other OS's is NOT supported.

Yeah, Poqet PC Classic probably can't be upgraded. Honestly, from the description (since I don't have one), I like the later models better due to more modern DOS (5), but proprietary / hard-to-find rechargeable batteries instead of AAs is annoying. Of course, a 386 would be better since most stuff needs it these days, but luckily I could hack a few minor things myself if needed.

> I have
> code which "kills" an existing DOS session allowing one to load a
> bootloader etc, yes similar to LOADLIN. I haven't tried it yet but in
> theory I should be able to use my code to boot something like FreeDOS.

Shouldn't be too hard considering DOSMinix and Linux (used to, 2.4) support booting atop DOS FAT.

> > He started it in 1989, which probably explains why he bothered to
> support
> > DOS 2!
> Check to see how he is supporting command-line parameters. I'd be
> interested to know. If it is a COM file, he may be doing it simply by
> poking straight into the PSP as the simple example in Wikipedia
> demonstrates:

Yeah, he's just using the standard "mov si,81h" and goes from there. (BTW, don't .EXEs have ES set to PSP at startup? So you don't need any undocumented calls, just use that.)

---
Know your limits.h

Complete thread:

• TOUCH.COM 1.4.3 (minor fix: debug script) - Rugxulo, 02.03.2010, 01:10 (Developers)
  • GZIPDATE.REX (uses TOUCH) - Rugxulo, 02.03.2010, 01:22
    • GZIPDATE.REX (uses TOUCH) - Arjay, 11.03.2010, 17:09
      • GZIPDATE.REX (uses TOUCH) - Rugxulo, 11.03.2010, 19:41
        • GZIPDATE.REX (uses TOUCH) - Arjay, 18.03.2010, 16:31
          • GZIPDATE.REX (uses TOUCH) - Rugxulo, 19.03.2010, 00:58
            • GZIPDATE.REX (uses TOUCH) - Arjay, 22.03.2010, 00:40
              • GZIPDATE.REX (uses TOUCH) - Rugxulo, 22.03.2010, 17:47
                • GZIPDATE.REX (uses TOUCH) / Tim Paterson / DOS v3 required - Arjay, 23.03.2010, 16:25
                  • GZIPDATE.REX (uses TOUCH) / Tim Paterson / DOS v3 required - Rugxulo, 23.03.2010, 16:59
                    • [deleted] - Arjay, 23.03.2010, 19:32
                      • TOUCH 1.4.4 - Rugxulo, 07.04.2010, 00:05
    • GZIPDATE.REX (uses TOUCH) - Rugxulo, 07.04.2010, 01:06