Hex Edit
Use a hex editor to edit the file AVATAR.DAT. (in the GAMEDAT directory) Change offset 2A to 01, and 2B to 01. Then reload the game and click on yourself. Press F7 for the same cheat menu, CTRL+F1 for a list of other things, and CTRL+F4 for immortality.

If you want to see the ending, make a file called I81B4U83.ICU with anything in it and put it in the STATIC directory. Now there should be an option of seeing the endgame sequence in the avatars' diary, as well as a quotes section.

Using an existing or new saved game in FIRST slot, simply type the below at the DOS Prompt :-

DEBUG
NU8SAVE.000
L
E 05F8 78 -- (Maximum Strength)
E 05F9 78 -- (Maximum Dexterity)
E 05FA 78 -- (Maximum Intelligence)
E 05FB F0 -- (Maximum Hit Points)
E 0625 C8 -- (Maximum Mana)
W
Q