def gen_header( program_name, start_address, program_length ):
	""" Generate a Header Record """
	
	#specify the size of each column
	col2_size, col3_size, col4_size = 6,6,6
	
	col1 = "H"
	col2 = program_name[:col2_size].ljust(col2_size).upper()
	col3 = hex(start_address)[2:].zfill(col3_size).upper()
	col4 = hex(program_length)[2:].zfill(col4_size).upper()
	
	return col1 +col2 + col3 + col4