Fundamental TechnologiesVoyager LECP Pages 
Table 4 Explanation of I*1 Representation
Bit 7 
Bit 6 
Bit 5 
Bit 4 
Bit 3 
Bit 2 
Bit 1 
Bit 0 
MSB 






LSB 
Table 5 Explanation of I*2 Representation (VAX Fortran
Volume 2 Language Reference Manual C1)
Bit 15 
Bit 14 
Bit 13 
Bit 12 
Bit 11 
Bit 10 
Bit 9 
Bit 8 
Bit 7 
Bit 6 
Bit 5 
Bit 4 
Bit 3 
Bit 2 
Bit 1 
Bit 0 
Sign 
MSB 













LSB 
Sign = 0(+), 1()
Integers are stored in a twos complement representation. INTEGER*2 values are in the range –32768 to 32767, and are stored in two contiguous bytes aligned on an arbitrary byte boundary. For example:
+22 = 0016 (hex)
7 = FFF9 (hex)
Table 6 R*4 Representation (VAX Fortran Volume
2 Language Reference Manual C5 and User Manual 10.5.1.2)
Bit 15 
Bit 14 
Bit 13 
Bit 12 
Bit 11 
Bit 10 
Bit 9 
Bit 8 
Bit 7 
Bit 6 
Bit 5 
Bit 4 
Bit 3 
Bit 2 
Bit 1 
Bit 0 
Sign 
Exponent 
Fraction 

Fraction 

Bit 31 
Bit 30 
Bit 29 
Bit 28 
Bit 27 
Bit 26 
Bit 25 
Bit 24 
Bit 23 
Bit 22 
Bit 21 
Bit 20 
Bit 19 
Bit 18 
Bit 17 
Bit 16 
Sign = 0(+), 1()
The exponent for the REAL*4 format is stored in binary excess 128 notation. Binary exponents from –127 to 127 are represented by the binary equivalents of 1 through 255.
For each floatingpoint format, fractions are represented in signmagnitude 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 is called “hidden bit normalization”). This bit is assumed to be 1 unless the exponent is 0. If the exponent equals 0, then the value represented is either zero or it is a reserved operand. 0.0 is any bit patter that has an exponent field of 0 and a sign bit of 0 regardless of the value of the fraction.
REAL*4 (F_Floating) data is four continguous bytes starting on an arbitrary byte boundary. Bits are labeled from the right, 0 through 31. The form of REAL*4 (Ffloating) data is sign magnitude, with bit 15 the sign bit, bits 14:7 an excess 128 binary exponent, and bits 6:0 and 31:16 a normalized 24 bit fraction with the redundant most significant fraction bit not represented. The value of F_floating data is in the approximate range 0.29 x 10^{38} through 1.7 x 10^{38}. The precision is approximately one part in 2^{23}; that is, typically, seven decimal digits.
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Last modified 5/4/05, Tizby HuntWard
tizby@ftecs.com