48-bit floating point
Norsk Data 48-bit floating point format:
The ND-500 and ND-5000 used only the 32-bit floating point format for single precision, and 64-bit floating point as double precision. The ND-100 (or -110, -120) front ends in those systems would normally have come with the 32-bit option in order to be compatible with their 500(0) companion. The 48-bit format described on this page is only used by the 16-bit ND computers.
|bit 47||1||Sign bit|
- The mantissa is normalized: 0.5 ≤ mantissa < 1
- The mantissa has no implicit bit, unlike the 32-bit and 64-bit formats
- The decimal point is thus to the left of the 32th bit (before exponent is applied)
- The exponent has a bias of 214, or 16384 (subtract 16384 to get true exponent)
- All 48 bits zero: Zero.
- (Any special value (e.g. -0) reprecenting floating point underflow is not documented in the ND-100 reference manual)
- 32 bits or approximately 10 decimal digits
- 2-16384 - 0.5 ≤ X < 216383 - 1 or X = 0
- approximately 10-4920 < X < 104920
- Norsk Data Document ND–06.014.02 ND-100 REFERENCE MANUAL