What are the DOOM cheat codes?
=====================================
Here is a list of the cheat codes from DOOM.  During play, just type
the codes in with the keyboard.  You need not hit ENTER after the code.
After entering, a message should be displayed at the top of the screen
telling which cheat mode was activated.

idbehold        Displays menu (followed by S, V, I, R, A, or L for 
choice)
                        S=Strength (Berserk)
                        V=Invulnerability
                        I=Partial invisibility
                        A=Full Automap (computer map)
                        R=Anti-radiation suit
                        L=Light amplification visors
  idchoppers      Gives you the chain saw (long story behind the 
message)
  idclev          Warp (followed by episode number and level number)
# idclip          No clipping (you can walk through walls)
  iddqd           Degreelessness mode (God mode)
  iddt            Toggles Automap between normal, full, and full with 
objects
                  (enter when in Automap mode)
+ idfa            Gives full ammo, 200% armor, and all weapons but no 
keys
  idkfa           Very Happy Ammo (full ammo, 200% armor, all weapons & 
keys)
# idmus           Changes the music to a certain mission (followed by
                  episode and level number)
  idmypos         Displays your bearing and coordinates in hex
@ idspispopd      No clipping (you can walk through walls)

#: Found only in DOOM II
@: Only found in in DOOM I
+: Only found in DOOM v1.4bt and up