[ubuntu-uk] Reverse engineering data files

[Gareth France]

Where did th 15 come from? 0x90b7 converts to 2487 according the the 
webpage I am using. How do you get from 15 to 0x0001? Why does 15 also 
convert to 0x0000?

>    0x90b7 >> 15 => 0x0001 => FAIL
>    0x4879 >> 15 => 0x0000 => PASS
>

Where does 0x7fff come from? How do you get to 0x10b7? You are telling 
me it all adds up perfectly but forgetting to tell me what act of 
wizardry is allowing you to do this.
>
>>>> > >>F3 01 90 B7  - 42.79 - 0x90b7 & 0x7fff => 0x10b7 => 4279 decimal
>>>> > >>F3 01 97 78  - 60.08 - 0x9778 & 0x7fff => 0x1778 => 6008 decimal