hiscore have 4 tracks out that i know of: tacker, identify, drone VII, and the classic true freedom... all released on a pair of 12"s. i have them both at home so i could tell you who the guys are but if i recall correctly, hiscore was the early name for kopfuss resonator... but if you compare their latest album to the hiscore material you'd NEVER be able to guess... only with tracks like whipbird could you have a clue, probably... or the early kopfuss tunes released on nephilim [can't remember what they're called though]...
BTW there is no Xor in their name - symbiosis added that i believe. none of the 12"s i have say "xor"...