This is the extremely rare first release of the game, before it was picked up by Sierra. This is the only copy I have ever seen so not much information is available on it unfortunately. This was one of the first games released by Al Lowe of Leisure Suit Larry fame. According to him:

In 3 months (while fully employed as teachers), we started a company, wrote, coded, drew, tested, debugged, packaged and sold two games, DK (Dragon's Keep) and Troll's Tale. When Ken and Roberta (Williams) saw them, they flipped - because "they look just like" Roberta's games. Ken then acquired them (and me) and sold many more copies in a "real" box. They were a manual, disk, and a business reply registration card, all in a plastic baggie we bought from Bradley Bag in L.A.