VMS Help FORTRAN, Intrinsic Procedures, ISIGN  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  ISIGN (value, sign)

  A function that assigns the sign of the second argument to the
  absolute value of the first.
  +------+---------+----------+------------+-------------+
  | Args | Generic | Specific |  Argument  | Result Type |
  +------+---------+----------+------------+-------------+
  |  2   |  ISIGN  | IISIGN   | INTEGER*2  | INTEGER*2   |
  |      |         | JISIGN   | INTEGER*4  | INTEGER*4   |
  +------+---------+----------+------------+-------------+
  See also the SIGN intrinsic function.