You need key 28. I'm not 100% sure, but whatever you set your base denomination to be, is the amount of credit you will receive. But you will need to setup multi-denom I believe for this to work. So set base denom to $100. Then for every token, you get $100 credit, then you can just choose the lower denoms to play for a while with just the 1 coin. To convert to coin you also need to look at the bottom part of your main door. On true coinless machines, the whole are is covered by a plate, so there's no hole for the coins to come out of the hopper into the tray. There's a plastic cover that replaces the plate which has the correct holes for the coins to come out of. I don't have a picture of one with me, but I can post it when I get home.