I did a search and after 5 pages of not finding it I gave up and just decided to ask you guys. Where is the PCM or ECU or ECM located in a 93 mark? Theres one at the junkyard near me and my friend wants to drop the motor into his 90 notch.

Above the pedals under the dash on the drivers side. Pull the cover and its right there.

Technically correct... It's on the firewall, behind the pedals, to the left of the brake pedal.