DOS ain't dead

hot dos (Developers)

posted by ecm  , Düsseldorf, Germany, 08.05.2025, 20:07

> > For instance, idling with sti and hlt, if it
> > works,
>
> What is the reason this might not work?

Virtual Machines or Virtual 86 Mode Monitors may either support idling with HLT, ignore the HLT silently, or even treat it as a fault exception. Likewise in DPMI Protected Mode, a HLT may not be supported by the DPMI host.

On dosemu2's (native mode, no KVM) DPMI host HLT leads to a GPF.

Using HDPMI32 on a qemu VM (no KVM), HLT appears to be fully supported, both running without throwing an exception and apparently idling the CPU.

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l

Complete thread:

• hot dos - kerravon, 08.05.2025, 00:24 (Developers)
  • hot dos - ecm, 08.05.2025, 00:36
    • hot dos - kerravon, 08.05.2025, 01:25
      • hot dos - ecm, 08.05.2025, 10:42
        • hot dos - kerravon, 08.05.2025, 12:55
          • hot dos - ecm, 08.05.2025, 20:07
            • hot dos - kerravon, 08.05.2025, 23:21
              • hot dos - ecm, 09.05.2025, 01:16
                • hot dos - kerravon, 09.05.2025, 02:01
                  • hot dos - Ringding, 09.05.2025, 14:33
                    • hot dos - kerravon, 09.05.2025, 15:22
                      • hot dos - Ringding, 09.05.2025, 16:13
                        • hot dos - kerravon, 10.05.2025, 01:32
            • hot dos - kerravon, 13.05.2025, 09:04
          • hot dos - Ringding, 10.05.2025, 09:21
            • hot dos - kerravon, 10.05.2025, 14:40
              • hot dos - RayeR, 12.05.2025, 19:51
                • hot dos - kerravon, 12.05.2025, 23:02
  • hot dos - Rugxulo, 08.05.2025, 03:22
    • hot dos - kerravon, 08.05.2025, 07:24
  • hot dos - rmcconne, 11.05.2025, 15:15