#include <stdio.h>

const double BaudTable[] = {
	1200,
	2400,
	4800,
	9600,
	14400,
	19200,
	38400,
	57600,
	115200,
	230400};

int within3percent (double baud)
	{
	double	minval, maxval;
	int		retval, i;

	retval = 0;
	for (i = 0; i < 10; i++)
		{
		minval = BaudTable[i] * 0.97;
		maxval = BaudTable[i] * 1.03;

		if ((baud >= minval) && (baud <= maxval))
			retval = 1;
		}
	return (retval);
	}

void main (void)
	{
	int		SPBRG;
	double	temp1;
	int		spbrg0, spbrg1;
	double	baud0, baud1;
	float	OSCILLATOR;

	printf ("Enter the crystal speed (ex: 4 MHz = 4000000):");
	scanf ("%f", &OSCILLATOR);

	printf ("CPU Speed = %7.4f MHz\nSPBRG\t  BRGH=0\t  BRGH=1\n", OSCILLATOR / 1000000);

	for (SPBRG = 255; SPBRG != 0; SPBRG--)
		{
		temp1 = (SPBRG+1.0) * 64.0;
		baud0 = OSCILLATOR / temp1;
		spbrg0 = within3percent (baud0);
		
		temp1 = (SPBRG+1.0) * 16.0;
		baud1 = OSCILLATOR / temp1;
		spbrg1 = within3percent (baud1);

		if ((spbrg0) || (spbrg1))
			{
			printf ("%3d\t", SPBRG);

			if (spbrg0)
				printf ("%9.2f\t", baud0);
			else
				printf ("         \t");
				
			if (spbrg1)
				printf ("%9.2f\n", baud1);
			else
				printf ("\n");
				

//			printf ("%d\t%9.2f%s\t%9.2f%s\n",SPBRG,baud0,((spbrg0)?" OK":" "),baud1,((spbrg1)?" OK":" "));
			}
		}
	}