unless (open ($SERIALPORT, "+<", $comport)) {die "Cannot open $comport: $!"}
system("stty -cstopb hupcl ignbrk -iexten -echo -echoe -echok " . 
	"-echoctl -echoke -crtscts -ignpar cs8 9600 time 5 -icrnl " .
	"-ixon -opost -isig -icanon -F $comport");
die unless binmode($SERIALPORT, ':raw:bytes'); #numerous variations tried