If you select a one player game, and a new boxer, use joypad 1 to enter / pass boxers name.

Joypad 1, UP = 1, LEFT = 2, RIGHT = 3, DOWN = 4, BUTTON 1 = ENTER, BUTTON 2 = DELETE.

For example, you could press comsole pause button for P, then joypad 1 up to get P1, then press joypad 1 button 1 to enter, button 2 if you make a mistake.