

                 how to call dfgnbl9 from C++ program


	what does dfgnbl9 do?

	dfgnbl9 will ...

	1)  beep until any key hit.  beeps should be about 2 per second
	    regardless of your computer's clock speed

	2)  return the unsigned char value of the key hit

;----------------------------------------------------------------------

	what kind of program calls dfgnbl9?

	you call dfgnbl9 from a C or C++ program
	
;----------------------------------------------------------------------

	any restrictions on this program?

	ms-dos/windows/xp operating system
	386 cpu or better

;----------------------------------------------------------------------

	how do i call it from a C++ program?

	install the following code:

//-------------------------------------------------------
//	declarations
//-------------------------------------------------------

extern "C" unsigned char dfgnbl9(void);

//-------------------------------------------------------
//	variables
//-------------------------------------------------------

unsigned char bl9_dummy;   /* should be very first variable in caller program */
unsigned char bl9_key;


//-------------------------------------------------------
//	code
//-------------------------------------------------------
   bl9_key = dfgnbl9();


	see bl9p.cpp (included in this package) for a C++ program 
	that uses dfgnbl9 

        run bl9p.exe for demonstration


        note:  actual name of external module is _dfgnbl9
        according to borland conventions you should ...
        *OMIT* underscore (use dfgnbl9) in C++ program (see above).
        *INCLUDE* underscore (use _dfgnbl9) in linker list


	install above code into caller program  
	compile caller program
	add _dfgnbl9 to your link.  _dfgnbl9.obj included in package
	run linker
	run caller program

;----------------------------------------------------------------------

	any warnings about this program?


	1)  DO NOT USE THIS PROGRAM WHERE OTHERS CAN HEAR IT.  USE 
	    THIS PROGRAM ONLY AT HOME OR IN EMERGENCY SITUATIONS 
	    WHEN YOU **MUST** HEAR A BEEP.

	    the reason why is illustrated by the following scenario:

	    1)  you run a program which contains dfgnbl9, and
	    2)  you leave for a meeting.  then
	    3)  your program calls dfgnbl9, which
	    4)  beeps 4000 times, and
	    5)  just before it gets to beep 4001,
	    6)  the guy in the next cubicle destroys your computer 
	        with a large axe

	    constant beeping drives people CRAZY.  [don't ask me how i 
	    found this out.]

	    for the office, use dfgnbla which is part of this package.  
	    see readme.1st to find the docs for dfgnbla.


	2)  THE BEEP IS NOT VERY LOUD.  you may not hear it if tv or radio
	    is playing loudly.  it is loud enough for office use

;----------------------------------------------------------------------

	can i control the sound volume?

	no.  the hardware does not allow it

;----------------------------------------------------------------------
