Type the following codes in during gameplay:
dncornholio: God mode
dnkroz: God mode
dnstuff: All items
dnitems: All items
dnhyper: Steroids
dnview: Changes view (same as F7)
dnscottyxx: Warp to level xx
dnweapons: All weapons and full ammo
dnrate: Frame rate
dnskillx: Changes skill level to x
dnclip: No clipping mode
dncoords: Shows coordinates
dndebug: Debug info
dnkeys: All keys
dnshowmap: Show complete map
dnunlock: Unlocks all doors
dninventory: Gives all inventory items