T3-83(Screech) is an astromech unit built by Alec and his dead brother Ulic Prue. He has extinsive hacking skills in addition to being able to mount armor and weapon upgrades (He currently carries a stun blaster and a four Rocket boosters built into his legs) he can also plot hyperspace cources for Alec's custom C-Wing Starfighter.
T3-83 is feircly loyal but he is also a constant worrier. Most of his time in his slot in Alec's C-Wing is spent checking and rechecking saftey systems and keeping the engines ready to get them out of there.
Screech was first built and activated by the very Hutts who wanted to procur Alec on a permanant basis - sadly he ran over the Hutts tail trying to catch the Hutts pet when it got loose and was promptly slammed into the ground by the Hutts huge fist.
A few weeks latter Alec and Ulic found the battered and damaged T3 unit laying asside his partner HK-48 who had angered the Hutt when he'd shot the crimelords pet. The two droids were re-activated and gaurded by the boys until Ulic was killed and Alec left Tatooine.
Unlike Blade T3's memory of Ulic was not wipped and as a ressult he possesed the memory of Alec's brother and was more than happy to give Alec the full story on his dead brother when the lost master asked him about Ulic.
To this day Screech and Blade function together as a system of check and balances because of Screech's need to stay alive and Blade's desire to kill every moving thing that is a danger to his master. As a result the two are in a constant contest over who is right and just how the situation should be handled.