instructions a b -- a-b SUB -> Pushes a - b (byte) to the stack SUBw -> Pushes a - b (word) to the stack SUBx -> Pushes a - x (byte) to the stack SUBxw -> Pushes a - xw (word) to the stack SUBy -> Pushes a - y (byte) to the stack SUByw -> Pushes a - yw (word) to the stack SUBxy -> Pushes x - y (byte) to the stack SUBxyw -> Pushes xw - yw (word) to the stack