Porter needs you to secure a hard copy of the machine code from the Rapture Central Computing mainframe. Go to Computer Core Access and print out the code.
Maintenance
Hack the Security Camera directly above the Health Station as soon as you arrive. Swap to the Speargun and snipe the Splicers that appear from the right-hand door, then switch to something a bit more powerful for the Fiery Brute Splicer coming from the left. Hit him with Winter Blast as he steps within sight of the Security Camera.
The door controls to the Core Access have been sabotaged, so you’re going to have to go another way. Porter needs you to proceed through the maintenance area, down the stairs on the left.
Continue north through the maintenance area, clambering up and over the wooden crates as you go. Zap open the door to the Cable Room and drop off the ledge into the water-filled pit below. Crouch down and make your way through the utility shaft to find the Fountain of Youth tonic. Hang out where you are in the water until your health has replenished and continue on. Ready the Ion Laser and open fire on the pair of Mini-Turrets that get deployed in your path.
Ready the Hack Tool as you proceed under the pipes and up the ramp in the distance, as there’s a Turret waiting for you out of the water. Continue past the Turret, then crouch down once again and crawl through the ventilation shaft to the left of the blockaded door. Drop off the ledge and pick up the Audio Diary (“Rapture Departure Protocol”) illuminated by the spotlight. Ascend the stairs to find several Heat-Seeking Rockets and go through the door to the Computer Core.
Computer Core
Take a moment upon reaching the Computer Core to hack the Health Stations on the ground floor and to stock up on ammo and, more importantly, EVE Hypos. Ensure that you have Hypnotize equipped. Summon a pair of Elite Security Bots, then ascend the stairs to the control room where you find the code printer you need.
