In 1978, Lawrence purchased the Commodore PET 2001 and no longer needed the university's computer, though the microcomputer's lack of memory was his primary design obstacle. He rewrote "DND" as "Telengard" within eight kilobytes of memory and designed the dungeon to be procedurally generated based on the player-character's position so the maps would not have to be stored in memory. The final version almost completely used 32 kilobytes of memory. It was easily ported to the Apple II+ and TRS-80 platforms due to their similar usage of the 8K BASIC programming language. The later Atari 800 port required a more complicated handling of string variables. The three ports were finished before Avalon Hill saw the game at a gaming convention and licensed it in 1982 as one of its first computer games. The IBM PC port required a rewrite into the C programming language; the source code for this version was later lost. The Heath/Zenith CP/M version requires MBASIC. The game's Commodore 64 port was the most popular.