Question re more than 1 Player with Future Pinball (Solved)

[BobA]

I have never played more than 1 player in FP.   I am now trying to setup a bartop to play 2 players.   What inputs control the players?   The coin slots?  No matter what coins I put in Coin 1 and Coin 2 when I start the game there is only 1 player.   There is no other button than start game?    

Just a little confused as I must be overlooking the obvious.

Thanks

Edit: I guess it was obvious but not sure why it works this way.   Insert 1 coin in coin slot.  Press start and wait for the clanging to stop.  Insert 1 coin in coin slot and player 2 is added.   On the game I was trying there seemed to be only 1 coin slot accepting coins (Airport).   Key 6 was dead so Coin 2 never coined up.   Will have to try other games to see if this is due to the actual game only having 1 coin slot or ?