An early example is the type-in program "Darth Vader's Force Battle" for the TI-59, published in "BYTE" in October 1980. The magazine also published a version of "Hunt the Wumpus" for the HP-41C. Few other games exist for the earliest of programmable calculators (including the Hewlett-Packard 9100A, one of the first scientific calculators), such as the long-popular "Lunar Lander" game often used as an early programming exercise. However, limited program address space and lack of easy program storage made calculator gaming a rarity even as programmables became cheap and relatively easy to obtain. It was not until the early 1990s when graphing calculators became more powerful and cheap enough to be common among high school students for use in mathematics. The new graphing calculators, with their ability to transfer files to one another and from a computer for backup, could double as game consoles.