Comprehensive information about classic Doom.

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 DOOM I
+: Only found in DOOM v1.4bt and up

*9-2*: What command line parameters exist?
==========================================
        To use most of these parameters, start DOOM by typing:
"doom -devparm <parameter> <more parameters>".  If the "-devparm" parameter
is not needed, the parameter will be marked with a plus (+).  Most of these
parameters can be mixed and matched to create different effects.  For
instance, typing "doom -devparm -wart 1 8 -record demo01 -respawn" would
record a demo on episode one, level eight, with monster respawn.  Lastly,
typing F1 during development mode will allow a 256 color screen capture in
PCX format.
@<filename>                    Used to read in a command line parm file
-altdeath                      Activates DeathMatch v2.0 (v1.4 and above)
-avg                           Ends the game after 20 minutes
-cdrom                         Uses C:\DOOMDATA directory for data
-comdev                        Internal development, texture mapping
-config <file name>          + Reads an alternate configuration file
-control                       Unknown
-deathmatch                  + Starts NetDoom in Deathmatch mode
-debugfile <parameter>         Dumps debugging info to debug<parm>.txt
-devparm                       Puts you in developers mode
-episode <episode>           + Starts on episode (1-3)
-GUS                           Uses the original GUS instrument mapping
-GUS1                          Uses the new GUS instrument mapping (default)
-fast                      +++ Nightmare mode without respawn
-file <name w/ .WAD>         + Allows usage of an external PWAD file
-left                       ++ Sets up a network terminal for the "left view"
-loadgame <game number>      + Starts from a saved game (0-5)
-maxdemo                     + Specifies the maximum size of a LMP recording
-nodes <players>               + Starts NetDoom with 1-4 players
-noblit                        Internal bugging switch, useless
-nodraw                        Internal bugging switch, useless
-nojoy                         Does not use the joystick
-nomonsters                  + Starts the game without monsters
-nomouse                       Does not use the mouse
-nomusic                       Does not play background music
-nosfx                         No sound effects
-nosound                       No sound at all
-opl3                          Enables the stereo music through OPL-3 on PAS16
-phase                         Enables phase shifting on PAS16
-playdemo <name w/o .LMP>   #+ Plays back a recorded demo
-record <name w/o .LMP>      + Makes a demo recording until you finish or die
-recordfrom <0-5> <demo name>+ Records a demo from a saved game
-regdev                        Internal development, texture mapping
-respawn                     + Causes enemies to respawn in non-Nightmare
-right                      ++ Sets up a network terminal for "right view"
-shdev                         Internal development, texture mapping
-skill <skill level>         + Starts on skill level (1-5)
-statcopy                      Unknown
-timedemo <name w/o .LMP>    # Calculates the number of times the screen is
                               redrawn when playing a demo
-turbo <speed 1-255>           Increases the speed of the marine
-warp <episode> <level>        Warps to episode (1-3) level (1-9)
-wart <episode> <level>        Loads a PWAD named ExMy.wad
+: Does not require the "-DEVPARM" parameter.
++: If you have a network, try setting up a network game with three players.
    The three terminals should have the parameters:
                "doom -devparm -nodes 3 -left"
                "doom -devparm -nodes 3"
                "doom -devparm -nodes 3 -right"
    Then, set up the left and right terminal monitors next to the middle
    monitor, in a virtual-reality type configuration.  When you turn your
    head, you see the screen turned 90 degrees!  This ONLY works with
    versions 1.0, 1.1, 1.4, 1.5, and 1.6 of DOOM.
+++: Must be used in conjunction with the "-WARP" parameter
#: For the "-playdemo" and "-timedemo" options, if you give an LMP file name
   of "demo#" (i.e. "demo3"), then that internal demo will be played if the
   external LMP file is not found.  For example, to play the internal 1.6
   shareware demo #2 (multiplayer demo), type "doom -playdemo demo2".
   Additionally, when using "-timedemo," the game will give you two 
   numbers after you quit to DOS, GAMETICS and REALTICS.  To determine
   the DOOM frame rate use the formula (GAMETICS/REALTICS) * 35.