The keystrokes for P2 Joystick is working in notepad. Any suggestions why it wouldn't be working in the game?
It depends on the game.
Case in point, the Donkey Kong upright cab only has one joystick so P2 uses P1's controls. (alternating turns)

The DK cocktail cab has two joysticks -- the view is upright for the player whose turn it is.

If you didn't change the DIP switch menu setting from "upright" to "cocktail" and didn't remap the game's P1 controls to accept both P1 and P2 controls as P1 inputs, P2 will have to use P1's controls.
To remap the game's P1 controls to accept both P1 and P2 controls:
- Open the "Input (this game)" menu.
- Highlight an input like "P1 Up"
- Press Enter
- Press Esc (input changes to "none")
- Press Enter
- Press up on P1 joystick (input shows "Up")
- Press Enter
- Press up on P2 joystick (input shows "Up or R")
- Repeat with the other inputs until all P1 inputs will also respond to P2 controls.
If you make a mistake and want to return to the default setting:
- Press Enter
- Press Esc (input changes to "none")
- Press Enter
- Press Esc (input changes to default)
Scott