‘The second-year player, a seventh-round draft choice out of Nebraska, is one of the busiest players in the Bills camp as he is trying to learn two positions — tight end and fullback. "For a guy in his second year in the league, that’s about as tough as it gets," Jackson said yesterday during a break at St. John Fisher College. "I can’t think of anything harder, other than playing quarterback, than to have to learn two positions. "There’s no real scheme to it, you just know when you’re playing tight end you think about playing tight end, and when you’re playing fullback you think like a fullback and just go with it."’