Tim Hartnell (1951–1991) was an Australian journalist, self-taught programmer and author of books and magazines on computer games.
He set up The National ZX80 User Group with Trevor Sharples in 1980 producing a more-or-less monthly magazine entitled Interface.
Each game had a description of the program and an explanation of its implementation, sometimes with ideas for modifications; this was followed by the raw code, which the reader had to enter into the computer.
Although he created a wide variety of games, the code for all of them tended to be characterized by an outline-style organization that made it easy to discern the basics of how the program worked.
His prose showed a passionate interest in, and enjoyment of, the games he created; he tended to be imaginative, witty, and dramatic, as well as nostalgic - he had little use for graphics, favoring text games that let the programmer's and player's imaginations do the work of creating the setting.