Pokemon Red/Blue
PP Up

To get PP Up go to the Secret Dungeon (The Place where you find/found Mewtwo).
go to the north of the cave, do not go in the first ladder you reach, use a pokemon with surf to cross the river to get to the upper cave in the right corner, go in.
once you reach the lower floor go 1 Up 1 left 3 Down 1 Left 3 Down 2 Left 1 Down 2 Left 1 Down 1 Right 5 Down 3 Right 2 Up 1 Left 3 Up, there's the PP Up.
Use Dig or Escape Rope to Get out the cave.
Copy PP Up.
Use it on your Pokemon to increase the PP for each Attack.