Tristar was a German c64 (and later Amiga) cracking and demo group, formed in may of 1987 by previous members of the three groups Orgasmatron Crew (from Remscheid), Master Control Program and KGB Crew (from Wuppertal). The original founders were Frankie, Flynn, CCO and Terminator.
Swapper advert in Sex'n'Crime 1 (february 1989), listing a PLK address in Witten, Germany. The group arranged the Tristar Party 1989 in september. An interview with the group was published in Cracker Journal 16 (october 1989).
Cracker Journal 19 (march 1990) reported, "Tristar got an new original supplier. It's a member of the famous C-64 group Action." - we assumed this refers to Spitfire. The march 1990 cracktro for Rock Star Ate My Hamster welcomed Leffty and Tim to the group. The group ceased to exist in its own right when they merged with Red Sector Inc in june of 1990, creating the now legendary group Tristar Red Sector Inc (TRSI).
Tristar was officially declared dead by organizers.
Some members went on to form a new group called The Solaris Agency (TSA). Source of information: forum post.