Back to home page

DOS ain't dead

Forum index page

Log in | Register

Search:  
Back to the forum
Board view  Mix view

DOS for 64 bits? (Users)

posted by kerravon E-mail, Ligao, Free World North, 08.11.2025, 00:50

> > > > > Can pdos run all ancient MSDOS programs, like Turbo Pascal, Norton
> > > > > Commander, etc?
> > > >
> > > > It can't run any of them. You need to recompile for the x64
> > > > platform.
> >
> > > Ok.
> > > I'll have some work to do, then!
> >
> > The chances of any of those things being C90-compliant are
> > close to zero, so it's not just a recompile that is required.
> So, the usefulness of PDOS for an end-user is very limited.
That's what kills almost everything. Like OS/2 or the Itanium.

When you tell people that there is a new platform with a new API,
and it's really fantastic, but it doesn't run your old software,
no-one is interested.

Although in both of the above examples, the old software did
in fact run. So even doing that isn't enough.

BTW, you're already in this zone yourself. Have you done a
market survey looking for how many people would like to
abandon 64-bit Windows and go to 64-bit DOS? While I
haven't done that myself, I doubt that there is any market.

There may be some circumstance where there is no choice
though. Like Microsoft shareholders demanding that a
reasonable profit is returned, and they jack up the price
10-fold, and businesses or people (perhaps in the 3rd
world - I don't know how it would play out) cannot afford
it. I would assume they would use Linux in that situation,
but they may run into a different problem that someone
who saw a commercial opportunity spent the effort to
get UCX64 working for some app, with the whole thing
closed source to protect their investment.

I don't know. I can't predict the future. I didn't expect that
the US would suddenly start a tariff war even on its
erstwhile allies. It could simply ban the export of Windows.
Anything is possible these days.

> I took the idea that 4DOS was public domain from
> https://web.crouze.com/the-return-of-4dos/ where it is said
> that "the old 4DOS is also still very much alive and kicking! The latest
> releases are in the public domain now, and have constantly been in
> development.".

Ok, some people use the term loosely. Meaning "freely available".

> > If that is the "target market" - then there are still alternatives -
> > like creating an extension to the MSDOS API that allows you to
> > write "directly" to an I/O port.
> Sorry, I just meant the least possible indirections.
Again - even MSDOS doesn't have the least possible
indirections. command.com could have read directly
from the keyboard via an I/O port. They did not do that.
They could have though.

Also - what is the purpose of reducing indirections? They
are there for a good reason.

Speed? Your application should be bottlenecked in the
application itself, not in the OS. Specifically it should
be CPU-bound, or really, "memory-access bound".

> > Or what about if the Windows 11 command prompt operated in
> > ring 0 - would you be happy then? Do you need it to bypass
> > virtual memory too? The PDOS "Windows clones" don't use
> > virtual memory - so that could be what you're after - bypass
> > the complication of virtual memory.
> There are videos in Youtube explaining how undocumented Intel cpu
> instructions allow someone to run in ring 0.
There are (or should be) other ways of running in ring 0 if you want.
ie an admin prompt or drivers. So long as it's your computer you
should be able to do whatever you want. I've never looked into
that though.

But getting into ring 0 probably won't help you. If you want to
get memory, you still need to go to the OS to get it. It's the
only one that knows the layout. And the background tasks
will still be running too. You don't have that complication with
UCX64.

This to me is really what it's all about. Do you want a system
that you can actually understand and maintain?

I think there is a reason why when you ring xyz company to say
that something isn't working, they tell you "no-one else is
complaining, just try again later".

The systems are too complicated and there are too few people -
in fact - zero people - who can maintain it.

> > > > I can guide you through it (in this forum, in text) if you start by
> > > > telling me where you want to run it. You can make a video at
> > > > the end of that process if you wish. Or a HOWTO. You offered
> > > > to do something non-programming for the "64-bit DOS", right?
> If PDOS can be useful to me, I'll do it, although at a slow pace.
Note that PDOS is most useful when your alternative is nothing.

There was an article on the BBC recently of a Japanese company
using pen and paper to take order after a ransomware attack.

PDOS may not be the world's greatest OS, but it can sure beat
pen and paper.

I don't know the details as to why they couldn't use another
system. Or even their smartphones.

> > In both cases, you just point it to the VHD (hard disk image)
> > within the zip file.
> I'd prefer qemu, as have not Virtualbox installed and would prefer not to
> waste space on it.
So use this for PDOS/386:

qemu-system-i386 -drive file=pdos.vhd,index=0,media=disk,format=raw

And this for UCX64:

qemu-system-x86_64 \
-drive if=pflash,format=raw,file=edk2-x86_64-code.fd \
-drive file=ucx64.vhd,index=0,media=disk,format=raw \
-m 2048 \
-nographic


If you are using Windows, change "\" to "^".

And search your drive for the edk2*.fd file - it should be somewhere -
and copy it to your current directory.

> > If 2 GB is a constraint for you, you might want to rethink your life
> > choices. :-)
> For a focused standalone desktop computer, yes, I agree.
> But it could be an alternative system for 64 bits to be able to process the
> very big amounts of data that we process nowadays and that were not
> available at the time of the legendary MS-DOS.
Sure. There have been new developments recently. We now
have the ability to target UCRTBASE instead of MSVCRT.
But that has created an agreement that we will now switch
to our own PCRTBASE with 64-bit long, for both 80386 and
x64.

Plus another development is that I can now build everything
on Linux etc instead of needing Visual C. ie even targeting
Windows, I don't need real Windows. So now I believe I am
in a position to write Linux scripts to build the entire
PDOS ecosystem, starting from a Linux gcc installation.

mcc should be properly exercised at that point, and I will be
in a position to see what happens if I lift the 2 GiB constraint
on memory.

> > His "solution" was to leave the industry.
> > My "solution" involves a return to MSDOS - or something similar.
> But to a mighty PDOS!
Right.

Also, you might want to consider this to be some sort of
"backstop" or "disaster recovery". People spend a lot of
effort ensuring they have a DR system. It's not meant to
ever actually be used. Ditto nuclear missiles.

That Japanese company wasn't supposed to ever be
using pen and paper either.

BFN. Paul.

Post reply
 

Complete thread:

Back to the forum
Board view  Mix view
22789 Postings in 2123 Threads, 402 registered users (0 online)
DOS ain't dead | Admin contact
RSS Feed
powered by my little forum