32-bit floating point

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Norsk Data 32-bit single precision format:

bit 31 (1 bit) Sign bit
bit 30-22 (9 bits) Exponent
bit 21-0 (22 bits) Mantissa

Exponent has a bias of +256. (Subtract 256 to get true exponent)

Special values for exponent:

All bits zero except sign bit: Floating underflow.
0 (binary 0, aka 0x00): Zero. Strictly speaking this is for the ND-500(0). The ND-100 spec says floating zero: All 32 bits zero. But any ND-100 introduced after the ND-500 would presumably be compatible, if not before.

Mantissa has an implicit 23th bit of 1 (unless mantissa is 0). This is the 0.5 bit, i.e. mantissa is normalised to be 0.5 < mantissa < 1.0

Decimal point is thus to the left of the implicit 23th bit.