#define CLOCK 0
#define DATA  3
#define PS_PORT portb

char read_key(char);

char read_key(char timeout)
{
	char count = 0;
	char key = 0;
	
	while (count < 255 && DATA == 1)
	{
		count++;	
	}
	
	if (count == 255)  return(0);
	
	
	
	return (key);
}