DOS ain't dead

Unable to return from DPMI real mode callback. (Miscellaneous)

posted by Japheth , Germany (South), 09.11.2011, 05:33

> Is it correctly understood that the real mode stack is a "raw" copy
> reflecting a 16 bit environment having 16 bit register pushed to it
> (meaning it is IP rather than EIP that is on top of the real mode stack)?

Yes. The Highword of EIP cannot be accessed in real-mode - and it is always 0.

Looking at your code sample, I wonder where register DS is loaded to access global variables ( i.e. cbCount and pRmRegs ). IMO it's very unlikely that the real-mode stack (DS:ESI) and your application's data segment are the same.

---
MS-DOS forever!

Complete thread:

• Unable to return from DPMI real mode callback. - tgr, 07.11.2011, 16:31 (Miscellaneous)
  • Unable to return from DPMI real mode callback. - Japheth, 07.11.2011, 17:29
    • Unable to return from DPMI real mode callback. - tgr, 08.11.2011, 23:15
      • Unable to return from DPMI real mode callback. - Japheth, 09.11.2011, 05:33