The 1975 mainframe game was the most popular software in the system for Minnesota schools for five years, with thousands of players monthly.[9][11] Rawitsch, Heinemann, and Dillenberger were not publicly acknowledged as the creators of the original game until 1995, when MECC honored them in a ceremony at the Mall of America.[6] By then, several versions of the game had been created. Rawitsch published the source code of The Oregon Trail in Creative Computing's May–June 1978 issue, along with some of the historical information he had used to refine the statistics.[12] That year MECC began encouraging schools to adopt the Apple II microcomputer, purchasing large amounts at a discount and reselling them to schools.[1][9] MECC began converting several of their products to run on microcomputers, and John Cook adapted the game for the Apple II; though the text-based gameplay remained largely the same, he added a display of the player's position along the trail on a map between rounds, and replaced the typing in the hunting and attack minigame with a graphical version in which a deer or attacker moves across the screen and the player presses a key to fire at it.[1][13] A version for the Atari 8-bit family, again titled The Oregon Trail, was released in 1982.[5] The Apple II version was included under the name Oregon as part of MECC's Elementary series, distributed to Minnesota schools for free and for profit to schools outside of the state, on Elementary Volume 6 in 1980.[1][5] Oregon was ported to the Commodore 64 in 1984 as part of a collection like Elementary Volume 6 titled Expeditions.[5] By the mid-1980s, MECC was selling their educational software to schools around the country, and The Oregon Trail was their most popular product by far.[14]