I created *a lot* of cheats for the PC Engine via the HUGO emulator (long since discontinued) and they were all included in the distribution .ZIP file – under the filename CHEAT.TXT.
Each hack was done using HUGO’s built-in ‘action replay’ functionality.
You stated a starting value (e.g. lives = 3) and search through the memory of the game for any locations where it could possibly be stored. You had to then intentionally lose a life and redo the search again. Rinse and repeat and then, eventually, you would find out where the lives counter was being decreased.
Once you found the address in memory, you could then either change the value at the address, or freeze it so that it was not allowed to be altered by any of the game’s code.
The file below is an updated version of the original text file from 2000, but I have converted into a Word document and then output it as a swanky looking PDF with much neater looking tables. I’ve not changed the content much compared to the original text file, other than change/remove old email addresses and websites.
I have no idea if this work has been replicated in Magic Engine because, at the time of creating the file, I didn’t think Magic Engine had a similar ‘action replay’ style system built-in.