With GET EDIT, reads a character string of length 'w'  composed  of
  the  characters  0 and 1; with PUT EDIT, converts the corresponding
  value to a character string.  The B format item  is  equivalent  to
  B1.

  B1 [ (w) ]

  w:

  A nonnegative integer or an expression capable of  being  converted
  to  an  integer that specifies the width in characters of the field
  in the stream.