Doom Wiki
This level occupies the map slot MAP20. For other maps which occupy this slot, see Category:MAP20.

MAP20: Central Processing is the twentieth map of TNT: Evilution. It was designed by Drake O'Brien and uses the music track "Horizon" by Tom Mustaine.


Central Processing is a very large map and it can be also very hard, especially on the highest difficulties. This is because of the large number of nasty monsters (especially chaingunners) and of the limited health that it offers. The level can be divided in three sections:

-A tech base where you can grab the red skull key

-A cavern-style part which is accessed through the red door

-A wide open area which is accessed through the yellow key and where the exit is

The wide open area is actually the biggest area in the map.


The tech base

Your starting area is a "T"-shaped hallway which contains imps and gunners. Turn right and open the door there. You'll now enter a black-walled room with several computer desks, imps and some other monsters. In this room is a teleport; step through and you'll be taken to a nearby chamber with some crates in it. Kill everyone that is in this chamber, then you can exit and get back to the computer desks room. A wall will have opened revealing many enemies, and a corridor to the right, with stairs that will raise when you walk into it. Continue up the stairs, dealing with the revenant and pain elemental that are revealed; you will eventually reach a slow elevator. It will take you to a long hallway with a blue platform on your right, and a corridor to the left. When proceed down the corridor or step onto the platform, traps will open up; the platform trap is much larger, exposing you dangerously to a horde, and also revealing the red skull key. Ascend the steps and take the key; taking it lowers another wall behind you, with gunners inside. The corridor trap -- which may be easier to handle first due to the greater amount of cover -- reveals a weird room with some pillars, a berserk pack and a teleport. This teleport will take you back to the start of the map, in the "T"-shaped corridor. Beware; two traps (one in front of you and one behind you) have opened.

The cavern

Take the left this time, to open the (red-keyed) door opposite the first door that you opened in this map. Deal with a couple of more traps. In the room you are in is a door; it will lead you to a slime pit, but there is another "secret" way to get to that area; in the same room is an opening to a long passage with enemies, slime and several small areas. Follow it until you get to a pit; drop into it, kill some monsters and grab the blue key. Find a wall that you can open and continue following the tunnels and killing some imps. Eventually you'll come to the slime pit. As soon as you shoot, lots of enemies will teleport in creating a dangerous situation. There is also the blue door, with more enemies inside. Once this large ambush is over, find a switch and shoot it. Now you're able to get the yellow skull key in a room next to you. You've finished the cavern part of the map. Only the wide open area remains.

The outdoor ending area

In the room with the yellow skull key is a pillar that you can open. Attempting to walk into the small room that is revealed will teleport you to a location near to the yellow door, in the tech base. Open the door and now you're in the final chapter of this mission (and the longest one). Kill all the enemies in your first area, which is an outside area with a temple-like building, a river and three balconies with gunners on them. There is also a small opening with easy to miss gunners. Once everyone is dead, drop into the river and follow it until you get teleported on a balcony. When you jump down, some enemies will teleport in a little pool of blood. Near this pool is a wide wooden door that will lead you to an extremely big outdoor area. Try to kill all the enemies that you can see, both on you shore and on the opposite shore of a long river. From where you entered, turn right and take the teleport. You'll be on the top of an island. Jump down and grab a soulsphere (being careful as it is guarded), then find an opening in the vines that surround you and jump down. Crossing this opening is mandatory to remove a barrier that lies on the long route ahead. At this point, you can progress towards the exit, but the monsters in the river will continuously shoot you. It is possible to kill them all. (If you find yourself running out of ammo, see the non-official secret below which helps you get some more). Leave the island and kill everybody that is in the river (included a dangerous spider mastermind). You also can kill the enemies on the upper ledges in the area you are in. Once you've finished destroying your foes, find a teleport and take it. You're back to the start of the wide open area. Follow some steps to a lift that you have to lower. Instead of jumping onto the other side, open a damaged-looking wall in the alcove you've just got and take the teleport inside (this is a secret). You'll be teleported to another ledge of the outside area. Follow the right side of it until you find a glowing skull decoration. Here you have to lower a giant lift that will take you to an area with several imps. Find an opening in the vine fences and jump down. Follow this ledge until you come to a teleport. Take it. Now you're in front of the exit switch!

Map of MAP20



  1. In the room with some crates in it there is a series of small crates leading up to the top of a large wooden box with some shotgun shells on it. Open the wall of the adjacent crate (it has a "3" on it) to reveal a secret area. One of the walls inside this secret can open, letting you exit. The first two secrets contain enemies, so if you want 100% kills you will need to access these.
  2. Accessing secret #1 will cause one of the walls in the crate room to lower, revealing some armor and a computer map. The outcropping near these items has a red brick texture; lower it for a medikit. Ride the lift back up and you'll reach a secret area with a BFG. While standing at the top of the BFG's pedestal, you will see a gargoyle face on the wall far to the south. Shoot it to lower the nearby gate, letting you exit through the teleport in the gargoyle's alcove.
  3. While traversing the tunnels in the cavern-style part of the level, you'll find a final long tunnel leading to the slime trail. The first half of this tunnel is tagged as secret area.
  4. The second half of the tunnel from secret #3 is also tagged secret.
  5. Upon entering the room with the yellow skull key, you'll see the long, diagonal wall to your left lower before you can reach it. Simply open it back up to get the bulk cell it hides.
  6. Just around the corner from secret #5 (directly across from the yellow skull key itself) is another openable wall with a slightly different texture from the ones surrounding it. This one holds an invulnerability sphere.
  7. The secret teleport near the lift in the huge outdoor area.


  1. Throughout the map there are various health and ammo items that can be seen but are on ledges high enough to be out of reach. After you take the secret teleport in the huge outdoor area (or reach that spot using the longer route), there will be another teleport just behind you. Enter it to visit each of these areas and collect the items (stepping off each ledge will take you to the next one).


  • It is possible to get stuck permanently if you don't have the super shotgun, and straferun from the BFG's pedestal into the barred corridor in secret #2, before you have shot the gargoyle face. Since the gate blocks your path in the north and the face lies too high to be hit from the corridor (except with the vertical scattering of the super shotgun), you can only load a saved game, kill yourself to restart the level or use the no clipping cheat to make an escape.
  • It is possible to become trapped, if you stand between the eastern lift, and the nearby floating rock.
  • If the Spider Mastermind enters the teleporter in the river, part of it can get stuck in a wall at the teleport destination, making it a sitting duck to kill using either weaponry or a telefrag.
  • Not so much a bug in itself as an opportunity to see one, collecting the Soul Sphere on the damaging floor in the outside courtyard is a great place to see the ouch face bug.
  • There is an unreachable energy cell pack inside the wall (not part of any sector) north of the yellow door.


There is another Central Processing in the original Doom.

A computer station

A big slime trail

Stairs before the end


Map data

Things 703
Vertices 2688
Linedefs 2436
Sidedefs 935
Sectors 321


Monsters ITYTD and HNTR HMP UV and NM
Spider Masterminds 1 1 1
Sergeants 18 32 27
Spectres 5 10 12
Imps 88 113 116
Demons 8 12 13
Barons of Hell 0 0 2
Troopers 5 4 3
Cacodemons 2 4 5
Lost Souls 16 15 7
Arch-Viles 1 2 2
Pain Elementals 0 4 7
Chaingunners 5 23 48
Revenants 3 8 11
Mancubi 1 2 3
Arachnotrons 1 4 6
Hell Knights 2 1 2
Powerups ITYTD and HNTR HMP UV and NM
Backpacks 1 1 1
Stim packs 12 15 15
Medikits 16 16 15
Soul spheres 4 1 1
Health bonuses 23 23 23
Armor bonuses 19 19 19
Green armors 1 1 1
Blue armors 1 1 1
Invulnerabilities 2 2 2
Berserks 1 1 1
Invisibilities 2 2 1
Radiation suits 3 2 2
Automaps 1 1 1
Weapons ITYTD and HNTR HMP UV and NM
Rocket launchers 1 1 1
Plasma guns 1 1 1
Chainsaws 1 1 1
BFG 9000s 1 1 1
Super shotguns 1 1 1
Ammunition ITYTD and HNTR HMP UV and NM
Bulk Cells 9 10 10
Shells 18 18 18
Rockets 16 16 16
Rocket boxes 10 9 9
Energy cells 2 2 2
Ammo boxes 19 19 23
Shell boxes 17 19 19
Blue skulls (Doom95 only, rest have blue cards) 1 1 1
Red skulls 1 1 1
Yellow skulls 1 1 1
Barrels ITYTD and HNTR HMP UV and NM
Exploding barrels 9 9 9

End of Level Message

The vista opening ahead looks real damn familiar. Smells familiar, too -- like fried excrement. You didn't like this place before, and you sure as hell ain't planning to like it now. The more you brood at it, the madder you get. Hefting your gun, an evil grin trickles onto your face. Time to take some names.



The Compet-N records for the map are:

Run Time Player Date File Notes
UV speed 02:39 Drew "stx-Vile" DeVore 2002-03-31
NM speed 07:18 Xit Vono 2002-08-10
UV max 10:21 Yashar "GeminI" Garibzadeh 2001-02-04
NM100S 07:18 Xit Vono 2002-08-10
UV -fast 15:39 Kai-Uwe Humpert 1997-01-21
UV -respawn
UV Tyson 43:37 Xit Vono 2002-11-10
UV pacifist 05:29 Drew "stx-Vile" DeVore 2003-04-25

External links