Castle Of The Winds Codes -

Increased constitution:
Continue casting the magic arrow spell even after running out of mana. Stop casting the spell when your character's current and maximum hit points have increased. You character's constitution should also be increased.

More HP:
Turn off visual effects in the options section under the file menu. Use a spell that increases your health. Use it until the screen stops showing your HP. Then, cast an attack spell (fireball, etc.) You will get a few thousand HP.

Maximum HP:
Cast any spell continuously until your mana reaches approximately -8000. When this happens the mana should stop decreasing when you cast a spell. Then, cast a healing spell and it will add to your HP until reaching 32767. Note: If you cast more health spells after you reach that number, your HP will turn into a negative number.

Easy item finding:
Create a character and select Detect Item as a first spell. Go to the dungeon, and save the game prior to descending a level in this or any dungeon. Enter the dungeon and cast Detect Items. If the items revealed are not desirable (spell books, armor, weapons, money), load the saved game and repeat. Since a different dungeon appears with each load, valuable items will eventually appear.