Advanced apologies for what is likely a novice question, but I have searched and poured through the forum and tutorials and still can't find basic instructions on what required techs are to design and build (or assemble) a PDC, missile or beam. I've created some basic designs that I think should work, but nothing ever shows up when I go into the construction screens or industry tabs in the PDC areas, either for building or pre-fab and then assemble PDC. Meanwhile I have colonists complaining everywhere and out the wazoo that they require protection
Thanks for your help and assistance!