So, I'll add a little bit to this.
First off, Tim is partially right. You can read and write to these open window roms and noone could tell without reading them with a reader. However, the checksum would tell if they had been altered.
Second, showing the roms and the boards in general is not meant to catch cheaters as much as it is to ensure the legit gamer is using the proper equipment. This can happen even when the gamer 'thinks' he is using the right stuff. Weibes Double DK would be one example, Robbies recent Joystick issue would be another.
The power supply rule was put in place because some people have seen issue with machines that had switching power supplies and mistakenly tied those issues to the power supply. That being said, simply saying 'the power supply does not matter at all' is to simplistic. For example Williams games lose bookkeeping and game play settings routinely when switching power supplies are used instead of the original linear ones. Some MCR games have weird sound issues when you use a switching power supply instead of the originals. As it relates to Donkey Kong, there is no evidence that a properly setup switching power supply has any influence on the game what so ever.
-Ken
