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From: R DOT Jaycocks1 AT lut DOT ac DOT uk (Robert Jaycocks)
Subject: cwsdpmi beta9 - Bug
Sender: usenet AT lut DOT ac DOT uk (Usenet-News)
Message-ID: <DL3739.Ct9@lut.ac.uk>
Date: Fri, 12 Jan 1996 21:16:21 GMT
Organization: Loughborough University, UK.
Lines: 25
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

In the latest version of the cwsdpmi program (beta9), what is the correct
method of redirection the int24 interrupt vector. This is required so that
the program prints up a user friendly message box if the user tries to 
access the drive, when there is no disk within the drive. The method I was
using, worked for the previous version, but now issues a page fault with
error=0006. 

The following piece of code illustrates what I was doing to setup the
redirection:

  _go32_dpmi_registers regs;
  _go32_dpmi_seginfo diskErrorInfo, OlddiskErrorInfo;

  _go32_dpmi_get_real_mode_interrupt_vector(0x24, &OlddiskErrorInfo);
  diskErrorInfo.pm_offset = (int)diskErrorHandler;
  _go32_dpmi_allocate_real_mode_callback_iret(&diskErrorInfo, &regs);

  int diskErrorHandler(_go32_dpmi_registers *r)
  {
    /* Perform int24 code here. */
  }

Thanks

Robert.