#!/usr/bin/perl

#
# Open and render the characters in the character generator.
#
# The working theory was that characters are mapped one per 16 byte row
# in the Motorola ROM dump, with seven bits of each byte forming a row
# of pixels, and 9 bytes (rows) of the 16 forming a character.
#
# Exceptions were found with bits set in column 8 and in row 10.
# These occur often in graphics glyphs, it's not likely bit rot.
#
open(INPUT, "331E4.mot") || die "331E4.mot: $!";
while (<INPUT>) {
   next unless /^S113(....)(................................)..$/;
   ($a, $h) = ($1, $2);
   # Don't render blanks.
   next if $h eq "00000000000000000000000000000000";
#warn "$a $h\n";
   for ($r = 0; $r < 16; $r++) {
     if ($r > 9) {
       next if $h =~ s/^00//; # Expect leading 00
       die "unexpected in row $r: $h\n";
     }
     printf "Code %03o:\n", hex($a)/16 if $r == 0;
     $h =~ s/(..)//;
     $b = hex($1); # Got a byte.
#    die "lsb $b: $h\n" if $b & 1; # Expect 7 bits!
     $b = sprintf("%8b", $b);
     $b =~ s/0/ /g; $b =~ s/1/X/g;
     print "$b\n";
  }
}
exit 0;