Got a bit of confusion regarding NES address $4017.
I've made a nice horizontal scrolling prog, with parallax (distant objects scroll slowly, closer objects scroll, well..fastly?), and Sprite 0 hit to allow a static status bar at the bottom.
All works well, and I of course had to study-up on how to use the joystick, including the use of the $4016/$4017 combo.
Then I look at the APU to learn sound, and I see the use of...gasp!...$4017 (frame counter). OK, so I know that there is only one $4017 address, so I assume that the hardware at this address does BOTH the joystick and sound?
But no documentation I have found says the equivalent of "do THIS to use the joystick, but use THAT to use sound".
So, assuming I am not going bonkers and it IS the same $4017, are there any docs that actually indicate the dual usage of this address? (and why not? - wouldn't someone accessing that hardware want the specs on ALL its' functionality?) Or is it expected that you simply read the appropriate doc for joystick, and the other appropriate doc for sound?
Or am I totally off base?