Your actual code does not really contain a bareword "N" between square brackets, does it? That would be bad. Show us more code, because (as the other reply says) the eq comparison of two 512-byte array elements should do the right thing (report true iff the two elements are in fact identical), as demonstrated below:

#!/usr/bin/perl

use strict;

my @array;
my $bgn = 0;
for ( 0..2 ) {
    push @array, pack( "c*", $bgn .. $bgn+511 );
    $bgn += 128;
}
# pack "c*" will only use the low 8 bits and strip off the higher ones
+, so
#  $array[0] will be identical to $array[2]

for ( 1, 2 ) {
    my $cmp = ( $array[0] eq $array[$_] ) ? "matches" : "differs from"
+;
    print "element 0 $cmp element $_\n";
}

__OUTPUT__
element 0 differs from element 1
element 0 matches element 2
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