Section 8,9,5: REAL

 Real and complex numbers are floating-point representations.

 The exponent for REAL (REAL*4) (S_floating) and DOUBLE PRECISION
 (REAL*8) (T_floating) formats is stored in binary excess 128
 notation.  Binary exponents from -127 to 127 are represented by the
 binary equivalents of 1 through 255.

 For floating-point format, fractions are represented in
 sign-magnitude notation, with the binary radix point to the left of
 the most significant bit.  Fractions are assumed to be normalized,
 and therefore the most significant bit is not stored.  This bit is
 assumed to be 1 unless the exponent is 0.  in which case the value
 represented is either zero or is a reserved operand.

 REAL (REAL*4) (S_floating) numbers occupy four contiguous bytes and
 the precision is approximately one part in 2**23, that is,
 typically 7 decimal digits.

 DOUBLE PRECISION (REAL*8) (T_floating) numbers occupy eight
 contiguous bytes and the precision is approximately one part in
 2**55, that is, typically 16 decimal digits.

 For more information on real data type ranges, see DATA CONSTANTS
 REAL and DATA CONSTANTS DOUBLE_PRECISION in this online Help file.