colinvella wrote:
The algorithm generates two code variants because bit 7 of the cheat Address is not used when decoding the cheat properties and can hence be either 1 or 0. The two variants differ only in the 3rd letter. For example, the codes GOSSIP and GOISIP both represent the same cheat (substitute $14 at address $D1DD)
When entering codes on an actual Game Genie, the high bit of the third letter helps move the cursor automatically to make entering codes easier.
After you enter the 6th letter, the Game Genie checks if the high bit of the third letter is clear. If so, it will move the cursor to the next line. (If you're on the last line, the cursor will stay on the 6th letter.) You can still add the 7th and 8th letters by pressing B to back up or by clicking on the 7th blank. Any 8-letter code is converted to a "compare and value" modification, no matter what the value of the extra bit is.
If the Game Genie thinks it was an 8-letter code, you can click on the next line to skip the 7th and 8th letters and enter another code. Any 6-letter code is converted to a "value only" modification, no matter what the value of the extra bit is.
But setting the extra bit correctly is a nice thing to do in case the code is ever used on a real Game Genie. When the bit is set wrong, you'll have to manually adjust the cursor.