E1M7: Computer Station (Doom)

E1M7: Central Processing is the seventh map of Knee-Deep in the Dead in Doom. It was designed by John Romero and uses the music track "Demons On The Prey". The par time is 3:00.

Walkthrough

 * Letters in italics refer to marked spots on the map. Sector numbers in boldface are secrets which count toward the end-of-level tally.

Essentials
Go through the door and take the first left. Follow the corridor to an alcove on your left (east) that is up two steps. Go in and up the lift in the southeast corner to find the yellow keycard.

Jump down, go out of the alcove and bear slightly left. Go through the yellow door and continue west. A lift will lower on your left; go up to get a rocket launcher if you like, and come back down. Continue west and follow the corridor as it turns south. Jog left and continue south, past the blue door, and you will come to a curved stairway going up and to the right. As you go up, a large column will lower (watch out for the sergeants). This column will rise again if you get on it, but for now, go around it and bear right (northwest). Follow along through a door and up a lift and eventually you will come to the red keycard.

Go back to the rising column, get on, and jump into the nukage pool to the right (south) when the column is high enough. (If the column rises without you, walk on the curved stairway to lower it again.) There is a walkway in the nukage with a chaingun (secret #1). Follow the walkway and a door will open revealing a backpack. As you approach, a wall will lower on your left, leading you back out onto the curved stairway.

The next maneuver may take several tries, so save first. North of the rising column is another nukage pool, and there is a dark doorway with a porch halfway up the east wall. You must ride the column up, nearly to the top, and jump over to the porch and into the doorway. There is a computer map here.

If you miss and fall into the nukage, and forgot to save, run quickly all the way north to find a soul sphere. A door will open to let you out into a hallway. Go south, then east through a yellow door, and then south again to return to the curved stairway.

Once you get the computer map, jump into the nukage and find the radiation suit just through the passageway to the northwest. Behind you is a red switch; click it to raise the wall it is on. Go upstairs (secret #2) to click another switch. This lowers the walls surrounding the chainsaw (see below).

Go back out into the nukage and turn right (northeast). There is a brown pillar with blue armor hidden inside it. Continue all the way north to the soul sphere platform (secret #3) and out into the hallway.

Turn left (north) to find the red door and the blue keycard behind it.

Come back out, go south, then east through a yellow door, and then zig-zag right, left, right, left, and right into a small room that has newly opened. (There are tracks on the doorjamb and a box of ammo at the back.) The east wall of this room is a door (secret #4) leading out to the courtyard with an invisibility sphere.

Come back in and make a U-turn to head south back to the curved stairway. This time, go past the rising column and through the big metal door to find the chainsaw.

Return, going down the curved stairway and through the blue door on your right. Go up the stairs, bear right and go around to a switch that opens the door leading to the exit. Go back toward the blue door but turn right (east) before the stairs. Follow the passageway to the exit.

Secrets

 * 1) At the top of the curved stairway is a large column that lowers as you go up the stairway. Get on, ride partway up, and jump south into the nukage. There is a walkway with a chaingun.
 * 2) Ride the large column up again to get into the nukage to the north. (Jump from the column onto the porch and into the dark recess to grab the computer map on your way.) As you go out to the northwest, where there is a radiation suit, there is a secret door with a red switch behind you. Go up the stairs to flip a switch.
 * 3) Go all the way north in this nukage pool to find a soul sphere and the way out.
 * 4) After collecting the blue keycard, a small room will open to the south of the computer room behind the yellow doors. The east wall of this room opens into a passageway out to the courtyard and an invisibility sphere.

Bugs
Four barrels (Things 112, 113, 114, and 187) have no flags set for any of the three difficulty classes, so they do not actually appear in the level.

Linedef 450 has its upper texture on the wrong side, resulting in a Hall of Mirrors effect. This is not normally observed, however, because the corresponding sector (a tiny hidden area of height 8 near the rocket launcher) is inaccessible without cheating. Similarly, linedefs 744, 745, 746, and 747 have their upper textures on the wrong side, but the HOM is visible only from the chainsaw platform before its walls have been lowered.

One end of the chaingun can clearly be seen through the low wall which obscures its platform (from the left edge of the curved staircase, or from the right side of the bridge if approaching from the chainsaw area).

The following actions can trigger the blockmap bug:


 * From the extreme western edge of the first room, firing into the central area (not along the blue gallery).
 * Firing along the blue gallery at a slight angle.
 * Attacking a Demon in the first section of the red key corridor.
 * Firing westward in the northern part of the large octagonal room.

Slime trails may be visible in the following locations (see screen shots below):


 * Just past the first door, looking toward the yellow key alcove.
 * Outside the red door, looking southeast.
 * At the T-intersection on the western edge of the first room, looking east.
 * Looking along the blue gallery from the west end.
 * Looking at the northern slime pool through the window in the first room.

Demo files

 * [[Media:e1m7secr.lmp|No monsters, 100% secrets walkthrough]] (file info)

Current records
The Compet-N records for the map are:

Inspiration and development
Early versions of this level appeared as E1M4 of Doom 0.4 and E1M4 of Doom 0.5.