#!/usr/bin/perl -w
use strict;

open FH, ">", "testingbin" or die "unable to open testingbin $!";

binmode FH;

foreach (1,2,3,4,5,6,7,8,9)
{
   my $buf = chr($_);
   syswrite FH,$buf;
}

close FH;

__END__
my text editor says: 0102030405060708 09 as binary bytes