Codes:

 Security level 3    FCDBMDEASDCAAADM
 Security level 3    FCCELDAAHDCAAAEK
 Engineering level 1 FKBDMDEAFDCAAAEB
 Science level 3     JGCJNDEAPDCAAACS
 Military level 3    EPAEMDEBBDCAAAEA
 Military level 3    IPCBSDADSDCAAACI
 Main tower level 2  LAAPJDAISDCAAACM
 Main tower level 2  LACJPDADSDCAAACS
 Main tower level 3  HCAPJDADSDCAAADD
 Main tower level 4  HCBPSLADSDCAAACB
 Stores level 3      EJDCPDAASDCAAADG
 Civilian level 3    EEHBNDAASDCAAADK

 Other               FKASMCEABDCAAADI
                     JGAFICEABDCAAAEJ
                     FKANLCEABDCAAADP

Cheats:

 Open the file TA.CFG with a normal text editor, change the value
 of DEBUG from 0 to 1. Now you can use the keys [1], [2] and [3]
 to leave the level in the game. Works only ca. three times, then
 you have to play the level.