Definitely had the pre-reqs(personal database, personal computer, researching, integrated devices) Heck even had a whole lot of dependent stuff: slave AI, optronics, overcharge radar, brainer outfit... but the tech itself did not show up as researchable and when I researched say, landmine, aye-phone would not come up. I wonder if the algorithm determining available topics does some kind of pruning and may skip a tech if it sees something dependent on it first?