Code/Doom 64=#1 Ultamate Code:Enter W93M 7H2O BYCO PSVB for your password. It gives you 100 health, 200 armor, all weapons, full ammo,backpack, the pentagram things, and it takes you to the last level. The pentagram things make your laser really super powerful. The also let you use the three swithches in the last level that close the gates that spawn monsters.
Code/Doom 64=#2 God Code:Enter ?TJL BDFW BFGV JVVB for your password. It will take you to level one. Then all you have to do is pause the game and go to the features menu. Now you can do lots of cool stuff.
Code/Doom 64=#3 Death Taunts:After you die, wait about 25 seconds. Some amusing taunts will appear on your screen