DB<5> =xb x unpack 'b*',
xb      = x unpack 'b*',
  DB<6> $_ = 'pqrs'

  DB<7> xb $_
0  00001110100011100100111011001110
  DB<8> $/ = '1234356577890'

  DB<9> xb $/
0  10001100010011001100110000101100110011001010110001101100101011001110110011101100000111001001110000001100