
Q: Why do some functions have the port selection as a 0~3 value in register A,
   while others are selected by the register DE
A: HIDLIB was made to be as simple as possible. Whenever it was possible, the
   DE pair was used because it yields the best performance. But mode complex
   devices (usually analog) require clocks or additional bitmasks to access the
   devices. In such cases, the A port value is necessary and used to calculate
   all the required bitmaps and masks.




