# Print Fixed Point #.16 Fraction # Theory Printing the fractional value of a 16-bit fixed point number in decimal is rather trivial. For example, the number `0.7106` in 16-bit fixed point is 0.71506 * 65536 = 46,569 = `$B5E9` How do we convert the number `$B5E9` back into `7106` ? By _digit peeling._ 1. Multipy N by 10 2. Print the Integer Part digit 3. Set the Integer Part to zero 5. Have we printed the number of decimal digits we want? If no then goto step 1 Example: ``` 0.7106 * 65536 = $B5E9 '.' $B5E9 * $A = $7.1B1A $1B1A * $A = $1.0F04 $0F04 * $A = $0.9628 $9628 * $A = $5.DD90 $5DD9 * $A = $8.A7A0 0.71058 _______________________^ ``` An optimization for N*10 is that this is equivalent to: `N*8 + N*2` # Application ## Assembly (Source) See file [print_fract.s](print_fract.s) ## Binary (Executable) ``` CALL-151 0800:a2 b5 a0 e9 20 15 08 a2 00 bd 70 08 20 ed fd e8 0810:e0 05 d0 f5 60 a9 00 8d 6a 08 8e 6b 08 8c 6c 08 0820:a2 00 20 60 08 20 54 08 20 60 08 20 60 08 20 44 0830:08 ad 6a 08 09 b0 9d 70 08 a9 00 8d 6a 08 e8 e0 0840:05 d0 df 60 18 a0 02 b9 6a 08 79 6d 08 99 6a 08 0850:88 10 f4 60 a0 02 b9 6a 08 99 6d 08 88 10 f7 60 0860:0e 6c 08 2e 6b 08 2e 6a 08 60 00 00 00 00 00 00 0870:00 00 00 00 00 800G ``` ## Output ``` 71058 ```