C Type sizes
                    PC         Range           Arc        Range
*char                8                          8 
 unsigned char       8           0..255         8           0..255
 signed char         8        -128..127         8        -128..127
*short int           8                         16
*unsigned short int  8           0..255        16           0..65535
*signed short int    8        -128..127        16      -32768..32767
*int                16                         32
*unsigned int       16           0..65535      32           0..4294967296
*signed int         16      -32768..32767      32 -2147483648..2147483649
*long int           32                         32
 unsigned long int  32           0..4294967296 32           0..4294967296
 signed long int    32 -2147483648..2147483649 32 -2147483648..2147483649
 float              32                         32
 double             64                         64
 long double       128                         64 (pending change to 128)

*shouldn't be used, as non-portable.