DOS ain't dead

OS/2 extender (Developers)

posted by kerravon , Ligao, Free World North, 17.10.2025, 17:41

> > https://www.os2world.com/forum/index.php/topic,3980.0.html
>
> I tried to register an account at the OS2 world forum specifically to reply
> to the thread there, but that would require admin approval, which is not
> forthcoming.

I have asked the question myself.

> From a reply in this thread:
>
> > You can have 16/32 code or 32/64 code but not 16/32/64.
>
> That’s what I thought, but it is incorrect. Long mode can deal with all
> three code segment sizes at the same time, as indicated by the very first
> table in the system programming volume of AMD’s architecture manual
> (“Operating Modes”). What you cannot have is VM86 mode. I verified PM16
> on my current Linux installations last week (from a 32-bit task). One
> significant piece of functionality is missing, although this is just a
> limitation of Linux, not the machine architecture: having your own SIGSEGV
> handler intercept general protection faults from that 16-bit code segment.
> Unfortunately, the kernel does not understand this kind of code and will
> kill the faulting process directly instead of invoking its signal handler.

I'm having difficulty understanding the replies - to the point where
I'm not even sure if people are talking cross-purposes.

But what are your thoughts about TWO replies that were given in the above
thread?

Complete thread:

• OS/2 extender - kerravon, 10.09.2025, 21:05
  • OS/2 extender - Rugxulo, 10.09.2025, 21:30
  • OS/2 extender - Ringding, 11.09.2025, 17:44
    • OS/2 extender - kerravon, 11.09.2025, 17:57
      • OS/2 extender - Ringding, 11.09.2025, 20:41
        • OS/2 extender - kerravon, 12.09.2025, 00:08
          • OS/2 extender - Rugxulo, 12.09.2025, 04:07
            • OS/2 extender - kerravon, 12.09.2025, 16:55
          • OS/2 extender - Ringding, 12.09.2025, 17:20
            • OS/2 extender - kerravon, 12.09.2025, 18:03
              • OS/2 extender - Ringding, 01.10.2025, 18:54
                • OS/2 extender - kerravon, 17.10.2025, 17:41