/*  DA_INT.C
 *
 *  Analog Output Routines for the SBC1190 with 4 Channel D/A option
 *
 *  This example uses the special Micro/sys system interrupt to
 *  write to the onboard D/A convertor.
 *
 *  8/3/98
 */


#include <conio.h>
#include <dos.h>
#include <bios.h>



/*-----------------------------------------------------------------------*     
 *  analogwr(int chan, int dta)                                          *
 *          This function writes to an analog output given a channel     *
 *          number of 0 to 3                                             *
 *  Return value : nothing                                               *
 *-----------------------------------------------------------------------*/
void analogwr(int chan, int dta)
{
	union REGS regs86;

        regs86.h.ah = 0xDD;     /* special Micro/sys system function */

	regs86.h.al = 0x30;     /* output to D/A convertor */

	regs86.h.bl = chan;

	regs86.x.cx = dta;

	int86(0x1A, &regs86, &regs86);
}



void main(void)
{
	unsigned n;

	for(;;)
	{
		/* output all values from 0 to 0xFFF */
		for(n=0;n<0x1000;n++)
		{
			analogwr(0, n); /* channel 0 */
			analogwr(1, n); /* channel 1 */
			analogwr(2, n); /* channel 2 */
			analogwr(3, n); /* channel 3 */
		}
	}
}