It’s almost like they were expecting GOG to release Ultima 7… …that’s right, Dragons and Dragonettes: both Pix’s Ultima Patcher for Windows and Xarton Dragon’s more cross-platform Portable Ultima Patches have been updated to...
The Good Old Games version of Serpent Isle evidently doesn’t come with the map or cluebook included as extras. Until such time as I can work with GOG to get these things added to the list of extras for the game, you can find links to both in this article.
Odkin figured out how to get a look at the Apple II source code, using only Apple II OS commands and the original game data files. While I can’t post his findings (e.g. the actual game code) here, his explanation of his method is something anyone with an original copy of Ultima and an Apple II could follow.