Underground CD Volume 1 Game System: Sony Playstation Cheat Category: Cheat Game Company: Unknown Game Category: Unknown Hint, Cheat, Walkthrough:   Playstation Underground CD ========================== (submitted by: _IMP_ [TML]) VIEW R-TYPE DELTA CODES: At the Main Menu of Disc 1, hold L1 + L2 + R1 + R2 and press Triangle. TOGGLE BACKGROUND MUSIC: At the Main Menu of Disc 1, press Start, then press Left or Right.