Bug Exploitation: "Infinite Saves"
As Carnby, when you leave the lobby of the manor, a cutscene begins and you meet Edenshaw. At the end of the cutscene he gives you a charm of saving. If you save immediately after the cutscene ends, then reload, the cutscene will begin again. Repeat. You will gain 4 saves each time.
Cheat mode enabling
To enable cheat mode in a game you should start it (ALONE4.EXE) with 'wizardmaster' or 'WIZARDMASTER' (no quotes) option in command line. Then when you enter the inventory, you will see the cheat menu there.