Underground CD Volume 4-1

Toggle Music - At the Main Menu of Disc 1, press R1 + R2 + Start.
View Grand Theft Auto 2 Codes - At the Main Menu of Disc 1, press L1 + L2 + R1 + R2.
View Sled Storm Codes - At the Main Menu of Disc 1, keep pressing L1 + L2, R1 + R2.
View WCW Mayhem Codes - At the Main Menu of Disc 2, hold L1 + L2 + X.
View NFL Gameday 2000 Codes - At the Main Menu of Disc 2, keep pressing R1 + R2, L1 + L2.

 