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                           Floating Point Formats

      IEEE 4 byte real

        31 30    23 22                        0
        +-------------------------------------+
        |s| 8 bits |msb   23 bit mantissa  lsb|
        +-------------------------------------+
         |      |                +----------------  mantissa
         |      +--------------------------------  biased exponent (7fh)
         +-------------------------------------  sign bit

      IEEE 8 byte real

        63 62      52 51                                  0
        +-------------------------------------------------+
        |s|  11 bits |msb        52 bit mantissa       lsb|
        +-------------------------------------------------+
         |      |                +----------------  mantissa
         |      +--------------------------------  biased exponent (3FFh)
         +-------------------------------------  sign bit

      Microsoft 4 byte real

        31     24 23 22                       0
        +-------------------------------------+
        | 8 bits |s|msb  23 bit mantissa   lsb|
        +-------------------------------------+
             |    |              +----------------  mantissa
             |    +----------------------------  sign bit
             +------------------------------  biased exponent (81h)

      Microsoft 8 byte real (see note below)

        63    56 55 54                                 0
        +----------------------------------------------+
        | 8bits |s|msb          52 bit mantissa     lsb|
        +----------------------------------------------+
            |    |                    +------------  mantissa
            |    +-----------------------------  sign bit
            +---------------------------  biased exponent (401h, see below)

      IEEE 10 byte real (temporary real)

        79 78       64 63 62                                     0
        +--------------------------------------------------------+
        |s|  15 bits  |1|msb          63 bit mantissa         lsb|
        +--------------------------------------------------------+
         |      |      |                    +-----  mantissa
         |      |      +------------------------  first mantissa bit
         |      +-----------------------------  biased exponent (3FFFh)
         +----------------------------------  sign bit

      Turbo Pascal 6 byte real

        47     40 39 38                                 0
        +-----------------------------------------------+
        | 8 bits |s|msb         39 bit mantissa      lsb|
        +-----------------------------------------------+
             |    |                  +------------  mantissa
             |    +-----------------------------  sign bit
             +--------------------------------  biased exponent (80h)

      Microsoft Fortran Complex number
        +--------------------------------------------------------+
        |   Float Real component   |  Float Imaginary component  |
        +--------------------------------------------------------+
        (each component is either 8 or 16 byte IEEE real)


        - sign bit representation:  0 is positive  and  1 is negative
        - in all float formats except the IEEE 10 byte real, the
          mantissa is stored without most significant bit; since
          the state of this bit is known to be set, it is not
          included and the exponent is adjusted accordingly
        - all formats use binary float representation
        - memory representation uses 80x86 reverse byte/word order.
        - Microsoft languages use the IEEE real formats;  BASIC is the
          only normal user of the Microsoft float format
        - Microsoft 8 byte real format has not been verified;  several
          Microsoft publications show an 8 bit exponent instead of 11 bits
          and state the BIAS is 401h;  the discrepancy is that 8 bits can't
          hold the value 401h (requires 11 bits)


      True exponent is the exponent value minus the following bias:

        81h for Microsoft 4 byte real
        401h for Microsoft 8 byte real
        7Fh for IEEE 4 byte real
        3FFh for IEEE 8 byte real
        80h for Turbo Pascal 6 byte real

           Size                  Range             Significant digits

        4 byte real       8.43x10E-37 to 3.37x10E38         6-7
        8 byte real      4.19x10E-307 to 1.67x10E308       15-16
        10 byte real     3.4x10E-4932 to 1.2x10E4932         19


        - see   dmsbintoieee()   dieeetomsbin()   NUMERIC RANGES