Konami Collector's Series: Castlevania & Contra

Jackal


It was discovered that the game contained somewhat altered NES ROMs of the Castlevania and Contra games soon after it was released. The games had several small changes, which were mostly done to remove any references to Nintendo on the title screen. A Jackal ROM was also found in the executable. The ROMs themselves were released after the discovery was posted at a message board on December 2002, and they've been available on the internet since then.

Despite the fact that it's in there, Konami never revealed a code to play Jackal in the emulator itself. However, you can trick the program into loading Jackal by using Cheat Engine. Start the game, and once you get to the game selection menu, run Cheat Engine, select CC.exe from the process list, and modify memory address in byte form so its value is 5. Return to the game, press Enter, and Jackal will load up. The actual memory address found by Cheat Engine is, but the relative memory address adds to its actual location.

Keep in mind that if you change the value of this memory address before the game selection menu loads completely, the program will crash.