use strict;
use English;
use Fcntl;

sysopen(PORT,"LPT1",O_RDWR) || die "can't open port\n";
syswrite(PORT,0x0);
print "Hit <enter> to change output value:";
my $in = <stdin>;
syswrite(PORT,0x1);
print "Hit <enter> to finish:";
my $in = <stdin>;