DOS ain't dead

DOSes written in assembly (Developers)

posted by kerravon, Ligao, Free World North, 07.04.2024, 16:55

> > Can you explain why it is not appropriate for FreeDOS to be written in
> C?
>
> I didn't say "appropriate", I just don't like C, no offense meant. I tried
> to learn C by starting with Borland C but then my programs wouldn't compile
> under GCC nor CodeBlocks: each had its own complaints.

Sounds like you didn't write according to the actual C89/C90
standard, which is available here:

https://nvlpubs.nist.gov/nistpubs/Legacy/FIPS/fipspub160.pdf

and a total joy to read.

Show me one single program that follows the C90 standard,
and compiles on Borland C, but doesn't compile on GCC etc.

> Also I'm happy with
> FreePascal/Lazarus. I'm trying to run UCSD Pascal under DOS and, if
> possible again, even as a bootable version. But that is just dreaming now.

My question is more generic, but you appear to have
answered it below, which would have been "what's
wrong with Pascal for writing an OS?".

> > But I'm interested in what you perceive the technical reasons are.
>
> My technical reasons: it should run on old machines with maybe 64 KB of
> memory, like the first IBM 5150 PCs. Programs written in assembly are
> smaller and faster than ones written in C or Pascal.

Ok, yeah, I more-or-less exit the game if there is less
than 2 MiB available. Others can compete in that space.

> > I know of LK-DOS. I can contact the author to find out where it is
> > currently if you are interested.
>
> I am interested indeed. I also found
> Snowdrop in the mean
> time.

Ok, he doesn't have it available for public download
(anymore?), and instead just sent it to me in Discord,
so I have uploaded it myself.

http://pdos.org/LK-DOS_Pre-Alpha_6.zip

In addition, you specified open source, but apparently
he hasn't released the source yet, but given that it
is written in assembler, a disassembly will presumably
get you close to the original.

He wanted it to be able to run in 16k of memory.

> > But I'm more interested in why you are choosing the 8088/8086 for a new
> > OS.
>
> The same reason why people think that it is fun to drive old-timer cars.

Ok.

> > And what's the reason to not use the OS/2 1.x or MSDOS API? Is there
> > something wrong with it? If so, can you elaborate?
>
> Almost nothing, OS/2 and MS-DOS are not written by me :)

So? Even if you're writing something new, if there is
nothing wrong with their API, is there any reason to
not copy it?

> Again, this is a pure fun project that probably won't make any sense to
> other people. Another thing: I want to document it in such a way that other
> people can use it as a base of knowledge how to create your own OS and FS.

Sure.

Complete thread:

• DOSes written in assembly - Ruud, 31.03.2024, 08:48 (Developers)
  • DOSes written in assembly - Rugxulo, 31.03.2024, 09:42
    • DOSes written in assembly - ecm, 31.03.2024, 10:01
  • DOSes written in assembly - Laaca, 31.03.2024, 17:09
  • DOSes written in assembly - boeckmann, 31.03.2024, 18:52
    • DOSes written in assembly - Ruud, 01.04.2024, 08:06
      • DOSes written in assembly - RayeR, 01.04.2024, 20:24
  • DOSes written in assembly - tom, 31.03.2024, 20:00
  • DOSes written in assembly - samwdpckr, 01.04.2024, 20:54
  • DOSes written in assembly - kerravon, 04.04.2024, 15:11
    • DOSes written in assembly - Ruud, 07.04.2024, 14:45
      • DOSes written in assembly - kerravon, 07.04.2024, 16:55
        • DOSes written in assembly - Rugxulo, 08.04.2024, 02:45
        • Disassembly quality - ecm, 14.04.2024, 19:33
  • DOSes written in assembly - rr, 07.04.2024, 17:24
    • DOSes written in assembly - Ruud, 07.04.2024, 21:48