Hey, I found out about the password machine. You know the factory where Sheppard says is dangerous? Well it is in there just follow the path then turn right. Go all the way back after you turn. You see two men.
Talk to them.
By one of the men, you will see two machines. The one on the right is the password machine, the other one is the card exchange.
One you put in the password, which you can find at Supercheats.com under yugioh ultimate masters for gameboy advance. But be aware that you are allowed only three on a tab.
So to get more cards, you have to go to deck edit, the put them under your current side deck, then go back to clear your tab on the rental pad. Which is the first man you see. Then just repeat the process.
Hope I helped. Happy gaming!
Added by: swanton_bomb2 Jan 2nd 2007, ID#1067