While playing, press Shift+Alt+J for all symbols.

While playing, press Shift+Alt+W for all weapons.

To use these codes, start your game with one of the following command lines:

TEKD1 NOCHASE-Removes the shooting enemies from the game.
TEKD1 NOENEMIES-Removes everyone but you.
TEKD1 NOGUARD-Removes the guards from the game.
TEKD1 NOSTROLL-Removes the innocent bystanders from the game.

While playing, press Alt-Shift-G for all weapons and invulnerability.

Press NUM LOCK while playing.