CompuServe Messages

Moto FFP Details?

    06-May-94 02:49:21
Fm: Shraddhan 70374,754
To: Syndesis 76004,1763
The ROM Kernel Manual – Libraries and Devices states the format of the Motorola FFP format. The current edition says that the format is 24 bits of mantissa in the range [0.5, 1) followed by 8 bits of excess-64 exponent. This cannot be correct. The previous edition (for WB 1.3) states that it is 24 bits of mantissa in the range [0.5, 1), then 1 sign bit and 7 bits of excess-64 exponent. This latter seems to be the (more) correct specification. The value is always normalised, except for 0.0 which is all zero bits. The old RKM says that the range of values is 5.42101070e-20 to 9.22337717e18, -9.22337717e18 to -2.71050535e-20, and 0.0 I hope this makes sense. Regards, Shraddhan (via AP from Hertfordshire, England)