Perl has the same bit-banging operators as C, if that's any help. The following should get you going

# powers of two. used to set, reset & test bits
my @bit = map { 1 << $_ } 0 .. 7;

#a number to play with
my $x = 0b10000;

#set bit 2
$x |= $bit[2];

#test bits 2 & 4
print "Y\n" if $x & $bit[2];
print "Y\n" if $x & $bit[4];

#reset bit 4
$x &= ~$bit[4];

#test bit 4 again
print "N\n" unless $x & $bit[4];

$x = 0b10000101; # 0x85

#get low order BCD digit
my $lo = $x & 0b1111;

#get high order BCD digit
my $hi = ( $x & 0b11110000 ) >> 4;

print "$hi $lo\n";

( $hi, $lo ) = ( 2, 5 );

#pack 2 and 5 into byte
$x = $hi << 4 | $lo;

printf "%b\n", $x
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