( Initializes the readln subsystem )
: RDLN$
    ( 57 == rdln's memory )
    H@ 0x57 RAM+ !
    ( plus 2 for extra bytes after buffer: 1 for
      the last typed 0x0a and one for the following NULL. )
    IN) IN> - 2+ ALLOT
    (infl)
    ['] RDLN< 0x0c RAM+ !
    1 0x06 RAM+ !  ( 06 == C<? )
;