use POSIX 'strftime';
my $clear = $^O =~ m/Win32/ ? 'cls' : 'clear';
while ( 1 ) {
    system $clear;
    @digits = split '', strftime("%H%M%S", localtime);
    print '  ', @digits, "\n  ------";
    for my $bin ( 8,4,2,1 ) {
        print "\n$bin ";
        for my $digit ( @digits ) {
            $digit >= $bin ? do {$digit -= $bin; print "\052"} : print "\117" ; 
            # print $bin & $digit ? 1 : 0; # could use binary and to select
        }
    }
    sleep 1;
}

# this will show you all the possible octal char codes you might like to use
printf "\\%03o\t %s\n", $_, chr for 40..255;