open DisplayIO, "+> /dev/cuaa1"		# open serial (display) device
		or die ("Can't open tty: $!") ;

sub main ()
{ 
        #code to loop &scrollTest several times with a sleep of 1 sec...
}

sub process_keyboard_input ()
{
	syswrite DisplayIO, $KeyBoardInput ; # write to display
} # process_keyboard_input 

sub scrollTest {

        syswrite DisplayIO, sprintf ("%c%c", 0xfe, 0x51);
        $KeyBoardInput = sprintf ("%cE%cX%s", 0xfe,0xfe,'HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH');
	process_keyboard_input ();
        sleep(1);
}

..