Date: Thu, 11 Jul 1996 11:56:16 +0200
Message-Id: <199607110956.LAA20242@ohm.fast.co.za>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
To: djgpp AT delorie DOT com
From: Alf Stockton <stockton AT fast DOT co DOT za>
Subject: int86x help needed

I am having a problem understanding why the following program fails.
I have read section 18 of the DJGPPFAQ a number of times & still it eludes me.

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

int main(int argc, char *argv[])
    {
    union REGS b_regs;                                  /* define registers */
    struct SREGS b_sregs;                       /* define segment registers */

    b_regs.x.ax = 0x3000;                              /* check dos version */
    printf("Checking DOS version.\n");
    int86x (0x21, &b_regs, &b_regs, &b_sregs);
    printf("after int86x call.\n");
    return(0);
    }

It is compiled with :-
gcc -Wall -g -O fubar.c -o bin\fubar.exe
under CWSDPMI(ie raw DOS)

and it produces :-
Checking DOS version.
Exiting due to signal SIGSEGV
General Protection Fault at eip=00001f3f, error=504c
eax=00003000 ebx=414c574e ecx=453d4547 edx=4155474e esi=00414756 edi=433d5544
ebp=3d545250 esp=0004b630 cs=00e7 ds=00ef es=00ef fs=00cf gs=00ff ss=00ef
Call frame traceback EIPs:
  0x00001f3f

I do know that there are other ways of checking DOS version but I particularly
want to use int86x as I am attempting to convert a function that uses multiple
int86x calls to DJGPP, if possible.
	Regards,
	Alf		stockton AT fast DOT co DOT za