Re: [Dev-C++] Where are int86() and union REGS?

[David M. <dml...@co...>]

What version of windows are you running if you are running any version 
of NT (including 2000 & XP) then no matter what the compiler you will 
get this crash. You will have to use a graphics library to program 
graphics on any of these OSes (allegro, SDL, OpenGL, DirectX, are some 
options you can look into.


James Dent wrote:

> Hello.
> I have been trying to program some low-level graphics routines for a 
> console application. All of the
> C++ books I have read have used the data structure union REGS to 
> represent the registry, and
> functions such as int86(), outport, etc. etc. (included in dos.h). 
> This header may be obsolete, or
> a Borland extension of C++ - I don't know. I turned to assembly to 
> accomplish the same function,
> but the code shown below resulted in the Blue Screen of Death when the 
> 'int' command was
> called.
>
> int mode = -1;
>
> void SetVideoMode (int local_mode)
> {
>    // This function consists of two parts: firstly, it saves the current
>    // video mode in the global variable oldmode, and secondly, it loads
>    // various values into the registry and calls the Video BIOS interrupt
>    // for changing screen mode.
>
>    mode = local_mode;
>
>    asm( "movb $0xF,%ah"         );          // The BIOS interrupt to 
> return
>                                                         // the video 
> mode.
>    asm( "int $0x10"            );                // The Video BIOS 
> interrupt.
>    asm( "movb %al,_oldmode"     );        // Stick the mode value (in 
> %al)
>                                                         // into the 
> variable oldmode.    */
>
>    // The old mode has been retrieved, now all that needs to be done 
> is the
>    // actual mode changing.
>
>    asm( "movb $0x0,%ah"         );          // Interrupt 0h - Screen 
> mode.
>    asm( "movb _mode,%al"        );         // Put the mode into %al
>    asm( "int $0x10"            );                // Video BIOS interrupt.
> }
>
> I have never been very good at assembly, but this code has been 
> terribly hard to debug. Does anyone
> know if a new version of the dos.h functions exists for Dev-C++, or 
> how to use assembly to the
> same extent?
>
> Gratefully,
>
>> From the Assembly-Migraine afflicted. 
>