I recently purchased the Ultima series from gog and decided to play them from the beginning.
Ultima 1 is... different. You constantly need to grind for health and after getting lost on level 5 of a dungeon and losing 5000 health and dying, I decided that rather than grind again to beef up, I would edit the game's save files.
ultima1_save_editor -o PLAYER2.U1 PLAYER1.U1
The above command will open the PLAYER1.U1 file and put the edited version in
PLAYER2.U1.
The program will ask you to adjust your name, stats, hit points, food, gold, etc.
I haven't tested the exact limits, but I wouldn't assign more than 200 or so for your stats (strength, agility, etc).
You can give yourself 999 intelligence, but this causes items in shops to be incredibly expensive since shop prices are based on intelligence, and having such a high int much cause an overflow. A 200 int is enough to drop those prices to 0.
On Mac OS X, the save files for the GOG version of Ultima 1 are located in:
~/Library/Application Support/Boxer/Gamebox States/com.gog.ultima-1/Current.boxerstate/C Ultima1.harddisk
I'm guessing that this program will work with any save file generated by the Ultima 1 remake from 1986