base:kernal_floating_point_mathematics
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| base:kernal_floating_point_mathematics [2020-04-22 06:06] – [7.3 Integer to FP] robin_8bst | base:kernal_floating_point_mathematics [2020-12-06 20:48] (current) – [7.1 FP to integer] pararaum | ||
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| ==== 7.1 FP to integer ==== | ==== 7.1 FP to integer ==== | ||
| + | There seems to be only a single routine in the ROMs, see Lothar Englisch, "The Advanced Machine Language Book", Abacus Software, 1984, p 28. IT is located at $BC9B and converts the floating-point value in the FAC (the fractional portion is truncated) into a whole number. The four mantissa bytes ($62-$65) contain the value in a big-endian representation. | ||
| ==== 7.2 FP to string ==== | ==== 7.2 FP to string ==== | ||
| Line 234: | Line 235: | ||
| **$bc44** = Convert signed 16-bit integer held in FAC1 at $63 (lo) and $62 (high) to FP\\ | **$bc44** = Convert signed 16-bit integer held in FAC1 at $63 (lo) and $62 (high) to FP\\ | ||
| **$b391** = Convert signed 16-bit integer held in Y/A (lo/high) to a FP number in FAC1\\ | **$b391** = Convert signed 16-bit integer held in Y/A (lo/high) to a FP number in FAC1\\ | ||
| - | **$bc3c** = Convert | + | **$bc3c** = Convert |
| **$b3a2** = Convert unsigned 8-bit integer held in Y to a FP number in FAC1 | **$b3a2** = Convert unsigned 8-bit integer held in Y to a FP number in FAC1 | ||
base/kernal_floating_point_mathematics.1587528409.txt.gz · Last modified: 2020-04-22 06:06 by robin_8bst