DOS ain't dead

ROM-BIOS leaves ds and es limits beyond 64 KiB (Developers)

posted by ecm  , Düsseldorf, Germany, 06.11.2025, 20:23

> > Interesting finding!
> >
> > Since this is real mode, I suppose another thing to try is to use the
> > 0x40:0x67 + CMOS 0x0f trick (as outlined in
> RBIL)
> > to reset the CPU segment registers to something like their power-on
> state,
> > and see what happens from there...
> >
> > (I recall it might be necessary to enable A20 for that, by the way.)
>
> I'm not finding anything on the web version of the list at fd.lod.bz/rbil,
> could you provide a link to that part?

This? https://fd.lod.bz/rbil/cmos/other/r0f.html

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Complete thread:

• ROM-BIOS leaves ds and es limits beyond 64 KiB - ecm, 28.10.2025, 17:20 (Developers)
  • ROM-BIOS leaves ds and es limits beyond 64 KiB - Oso2k, 28.10.2025, 21:46
    • ROM-BIOS leaves ds and es limits beyond 64 KiB - ecm, 28.10.2025, 22:03
      • ROM-BIOS leaves ds and es limits beyond 64 KiB - tkchia, 06.11.2025, 17:29
        • ROM-BIOS leaves ds and es limits beyond 64 KiB - ecm, 06.11.2025, 20:13
          • ROM-BIOS leaves ds and es limits beyond 64 KiB - ecm, 06.11.2025, 20:23
            • ROM-BIOS leaves ds and es limits beyond 64 KiB - tkchia, 06.11.2025, 23:07
  • ROM-BIOS leaves ds and es limits beyond 64 KiB - bretjohn, 30.10.2025, 16:49
    • ROM-BIOS leaves ds and es limits beyond 64 KiB - ecm, 30.10.2025, 18:49
      • ROM-BIOS leaves ds and es limits beyond 64 KiB - bretjohn, 31.10.2025, 01:45
        • LOADFIX - ecm, 06.11.2025, 20:20