Cheat Codes:
Debug Mode 
Get to the MS-DOS prompt, then enter the directory where you installed Ultima VII. Launch the game by entering the command "serpent manimal spam s".

Once you are officially playing the game, press the F2 key to get to the debug menu. There you can create items, change your stats, and do all kinds of stuff!

Press F3 to get to your TELEPORT map. Once in the map, click where you want to go.

Press F4 to use the VIBRATE SPELL.

Press F4 and then click on people, locked chests and more for a real treat! 

If you have the Silver Seed type "SERPENT MANIMAL" (this may need to my in lower case) 

Keys and effects are largely the same as from Ultima 7 part 2: Serpent Isle, 
apart from this cheat is a more user friendly version of the full debug mode available in Serpent Isle. 
The only difference I have heard of, is when casting a spell (F5), you are no longer prompted for a spell number - 
you must type the number, and press ENTER to receive it. Otherwise, just refer to the cheats/tables from Serpents Isle.