BCD floating point B12345678 (DFP085, B) 8-byte BCD encoded number. These are obsolete and should no longer be used.
The first byte of an B12345678 contains the sign and the base-10 exponent. The remaining seven bytes contain the 14 BCD digit mantissa. B12345678 values are transmitted in big-endian order.
The sign bit is the high order bit of the first byte; 0 means the value is positive, 1 means the value is negative.
The base-10 exponent is determined by subtracting 64 from the value of the low order seven bits in the first byte; the exponent ranges from -64 through 63.
B12345678 numbers are normalized so that the high order digit of the mantissa is non-zero unless the value is zero.
B12345678 values range from -9.9999999999999e63 through -1.0000000000000e-64, 0, 1.0000000000000e-64 to 9.9999999999999e63.
Some examples of B12345678 numbers:
1 => 0x4010000000000000
1e-64 => 0x0010000000000000
0 => 0x0000000000000000
-1 => 0xC010000000000000
-9.8765432101234e27 => 0xDB98765432101234