Various cheats

Code                    Effect
quicken                 god mode
rambo                   all weapons
skel                    all keys
kitty                   walk through walls
ravmap                  reveals entire map
massacre                kill all monsters on present level
cockadoodledoo          chicken mode
iddqd                   instant death
idkfa                   loss of weapons
ponce                   full health
shazam                  toggles weapon power
skel                    all keys
ticker                  FPS display
engageXX                level warp (episode/level) 
gimmeXX                 Artifacts (a-j) (1-9) 

a=Ring 
b=Mask of invisibility 
c=Potion 
d=Potion 
e=Tome of power 
f=Torch 
g=Time bomb 
h=Eggs 
i=Golden Wings 
j=Chaos device (warp to start of level)