Use the Enter Cheat Code screen on the menu to input these passwords:
themick - Adds Mickey Mantle (Rating 100) to Free Agents.
Black Sox - Unlock all cheats except the Topps cheats.
Game On - Unlock all extras.
Derek Jeter - Unlock everything but the Topps baseball card cheats in My Cheats.
mightymick - Unlock the Mighty Mick Topps cheat.
triplecrown - Unlock the Triple Crown Topps cheat.
m4murder - Unlock the Big Blast cheat