DOCERR: _int86() and _int86x() Examples Missing from Help File

The information in this article applies to:

• The C Run-time (CRT), included with: Microsoft Visual C++ for Windows, versions 1.0, 1.5, and 1.51

SUMMARY

The Microsoft Visual C++ version 1.0 help file, MSCXX.HLP, does not contain the sample programs to demonstrate the _int86() and _int86x() functions.

MORE INFORMATION

When you view the _int86() or _int86x() topics in Microsoft Windows Help and choose the "Example" jump, Help displays the sample code for the _getcwd() function. The text below lists the missing sample programs.

Sample Code for _int86x()

// INT86X.C: In this program, _int86x executes an Interrupt 21h to
// invoke MS-DOS system call 43h (change file attributes). The program
// uses _int86x because the file, which is referenced with a far
// pointer, may be in a segment other than the default data segment.
// For this reason the program must explicitly set the DS register
// with the _SREGS structure.

#include <signal.h>
#include <dos.h>
#include <stdio.h>
#include <process.h>

char __far *filename = "_int86x.c";

void main( void )

   union  _REGS inregs, outregs;
   struct _SREGS segregs;
   int    result;

   inregs.h.ah = 0x43;      // MS-DOS function to change attributes
   inregs.h.al = 0;         // Subfunction 0 to get attributes
   inregs.x.dx = _FP_OFF( filename );  // DS:DX points to filename
   segregs.ds  = _FP_SEG( filename );
   result = _int86x( 0x21, &inregs, &outregs, &segregs );
   if( outregs.x.cflag )
      printf( "Can't get file attributes; error no. %d\n", result);
   else
      printf( "Attribs = 0x%.4x\n", outregs.x.cx );

Sample Code for _int86()

// INT86.C: This program uses _int86 to call the BIOS video service
// (Interrupt 10h) to get information about the cursor.

#include <dos.h>
#include <stdio.h>

void main( void )

   union _REGS inregs, outregs;

   // Set up to get cursor information.
   inregs.h.ah = 3;       // Get cursor position function
   inregs.h.bh = 0;       // Page 0

   // Execute video interrupt.
   _int86( 0x10, &inregs, &outregs );

   // Display results.
   printf( "Cursor position\n\tRow: %d\n\tColumn: %d\n",
           outregs.h.dh, outregs.h.dl );
   printf( "Cursor shape\n\tStart: %d\n\tEnd: %d\n",
           outregs.h.ch, outregs.h.cl );
}