E1M6: Central Processing (Doom)

E1M6: Central Processing is the sixth map of Knee-Deep in the Dead in Doom.

Walkthrough
Head north out of the start area and take the first walkway heading east. Follow the pathway into a room and go all the way eastward where you will see the red keycard. Be careful as you collect the key, because five doors will open to release monsters. Go back out the way you came in. (You may have to wait for the door to the room to reopen.)

Go across the walkway extending north from the start area and continue on the first walkway heading west. There is a small open door across the nukage leading to a room with imps and powerups; visit if you wish. The walkway then leads to two red doors. Go through either one, as they both lead to the same place.

You will come to an area that branches off to the southwest of the passageway. The blue keycard is at the end of the pier in this area. Use caution as you approach the blue keycard: a door will open behind you and a demon and perhaps an imp or two (depending on the skill level) will come after you.

After getting the blue keycard, turn to the right (pointing northwest) and jump into the nukage pool. Quickly follow the wall on your right around in a U-turn to find a radiation suit. Go back into the main area of the nukage pool and find the passageway going southwest. As you enter this passageway, a platform will lower. Get on the platform and ride up to get a soul sphere (secret #1).

Go back into the main area of the nukage pool and head right to the northeast corner to find a walkway. Follow this walkway around (secret #2) and up a stairway leading to a light amplification visor, blur sphere and two boxes of rockets. Click the wall switch to open a door back into the start area of the level.

Head north out of the start area once again, this time continuing through the big metal door. Kill the monsters in the room behind the door. Then, head out to the east along yet another walkway crossing a nukage pool, and you will come to the blue door.

Go through the blue door and you will be in a maze. One way through is to stick to your left, circling the perimeter of the maze clockwise. Following this method (turning left whenever possible, turning right only when you cannot turn left or go forward), you will soon come to the easternmost edge of the maze. There is an off-color door here with armor bonuses arranged in an arrow pointing at it. Open the door to find a computer map.

Continue around the maze in the same clockwise manner and you will soon come to the southernmost edge. Here, there is a wall switch illuminated by flickering lights on the opposite wall. Flip this switch to open a door out of the maze.

Continue around the maze, still going clockwise, until you come to the door you just opened. It is on the west wall of the maze (on your left), bordered by metal trim, and leads to a hallway with blinking light. Before you enter this hallway, you may want to explore the center of the maze to find items and kill monsters.

Follow this hallway up some stairs to find the yellow keycard and a backpack. Again, a door will open behind you in the hallway to release monsters.

After getting the yellow keycard, exit that room to the south through the secret door behind the green armor. Here, you will find a room with a rocket launcher, blur sphere, and another backpack (secret #3). Go all the way east in this room, then turn north again and open another secret door. This leads to an area overlooking a nukage pool, the same one you crossed when approaching the blue door.

Grab the radiation suit here and head north across the nukage. Cross the walkway you used earlier and go all the way to the north wall. Turn right and you will see a passageway going behind a wall in the nukage. Go down this passageway as it makes an S-curve and goes into a nukage tunnel. Continue until you come to a platform with ammo (secret #4).

Open the door at the back (north) of this platform to overlook a courtyard. Jump down into the courtyard and you will see a soul sphere on a platform to your left. Walk toward it and the platform will lower. Get on and ride up. Click to raise the secret door/wall and enter the building.

Go forward and turn right (north) to go up the stairs. Throw the switch at the top of the stairs; this opens a door you will soon come to. Go back down the stairs, turn right and follow the walkway to the left. Continue on the walkway out over the nukage pool to see a door (which you just opened) across the nukage on your right. There are items hiding behind the columns in the nukage; get them if you like. Then, go through the door to the east.

The passageway splits three ways. The center passage, going upstairs, leads to a balcony that might be good for sniping, but is otherwise not interesting. Follow either side passage downstairs to a room with computer panels and blue trim. There is a switch on the west wall of this room, but again monsters will be unleashed as you walk toward it. After killing these monsters, click the switch. A door in the northwest corner will open, releasing some number of spectres. Go through this door in the northwest corner to find the exit.

Secrets

 * 1) Across the nukage pool from the blue keycard is a dark doorway. Inside, a passageway leads to a platform with a soul sphere.
 * 2) In the northeast of the nukage pool near the blue keycard is a passageway leading out to a light amplification visor and a blur sphere.
 * 3) To the south of the room with the yellow keycard, behind some green armor, is a secret door leading to a room with a rocket launcher, blur sphere, and backpack.
 * 4) In the nukage pool just outside of the blue door, a passageway behind a wall in the northeast corner leads to a platform with various ammo. To trigger the door to this passageway to open, it is necessary to first traverse the stairway at the southeast of the room with the yellow keycard.

Demo files

 * [[Media:e1m6secr.lmp|No monsters, 100% secrets walkthrough]] (file info)

Routes and tricks
The door to the red key room closes and remains shut for thirty seconds after the player enters, this is to prevent the player escaping when the red key trap is sprung. To avoid this substantial loss of time it is possible to block the door using a monster, one of the two Sergeants need the door being the most obvious choice. Simply move within the Sergeants' sight, while remaining outside the door, and they will approach the player. When one of the two is under or nearly under the doorway, rush forward past the enemy and into the room. If all goes to plan the player will activate the door trigger line, the door will attempt to close, be obstructed by the Sergeant and return to an open position. The player can then grab the red key and escape through the open door.

You may bypass the maze as follows: As you approach the blue door, the platform at the south side of the nukage pool will lower. Go through that area and through the two secret doors in the opposite direction from the above to get the yellow keycard. If desired, go down and back up the stairs leading toward the maze to trigger open the door to the secret passage in the northeast of the nukage. However, you can avoid using this passage by just going back to the central area and going through any one of the yellow doors.

You can also lock yourself out of the big room before the exit where you have to fight loads of creatures. First run into the alcove to trigger the doors hiding the critters to open. Take out all of them. The entrances to this room will open. Run out of the entrance to this big room. After a while the door will close. You will be locked out of the room, and cannot open the door.

Records
The Compet-N records for the map are: