Cheat codes are enabled at the copyright screen that appears after the game is reset. They are entered by pressing A to created a letter in Morse code. A dot is created by tapping A. A dash is created by holding A briefly before releasing it. The sound of Morse code will confirm correct code entry. Up to two codes can be enabled by starting the second code after the sound of the first code being confirmed is heard. However you are limited to activating the "C" or "D" codes first, then only the "R", "L" or "X" codes second.
You can activate one or two cheat-codes at copyrights screen (right after reset) by entering Morse codes using A-button.To enter Morse-dot, press A-button and release imediately.To enter Morse-dash, press A-button, hold it for 0.2-0.5 seconds, and release.For example, to enter Morse code "D" (dash, dot, dot) you need to perform this sequance:press A, hold A awhile, release A,press A, release A,press A, release A.If code entered correctly, you can hear sound of entered Morse-code.If you want to enter two codes, enter first of them, listen sound, then enter second, another sound will be heared.First code can be "C" or "D" onlySecond code can be "R", "L" or "X" only.