Hold L1 and R1 when selecting Original Mode to gain access to all three sound module modes.
On the title screen, input the Konami Code: Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start. You'll access a hidden screen with a few options. One is the time setting. Since this game was originally on a computer, the game occasionally used the internal clock to adjust aspects of the game (like the time on the clock tower and the season in the painting at the end of level 7.) Since the Playstation has no internal clock, you can set time and date here. You can also set the option as to whether the life bar is solid (like the old NES games) or whether its transparent.
Castlevania Games - Akumajo Dracula X68k - ADX68k Codes