I/O

(parse)  a -- n   Parses string at a as a number and push the
                  result in n as well as whether parsing was a
                  success in f (false = failure, true =
                  success)
(print)  a --     Print string at addr a. Stops at 0x0 or 0xd.
.        n --     Print n in its decimal form
.x       n --     Print n's LSB in hex form. Always 2
                  characters.
.X       n --     Print n in hex form. Always 4 characters.
                  Numbers are never considered negative.
                  "-1 .X" --> ffff


                                                        (cont.)
