Sargon (or SARGON) is a line of chess-playing software for personal computers. The original SARGON from 1978 was written in assembly language by Dan and Kathleen "Kathe" Spracklen for the Z80-based Wavemate Jupiter III. History SARGON was introduced at the 1978 West Coast Computer Faire where it won the first computer chess tournament held strictly for microcomputers, with a score of 5–0. This success encouraged the authors to seek financial income by selling the program directly to customers. Since magnetic media were not widely available at the time, the authors placed an advert in Byte magazine selling for $15 photocopied listings that would work in any Z80-based microcomputer. Availability of the source code allowed porting to other machines. For example, the March–April 1979 issue of Recreational Computing describes a project that converted Sargon to an 8080 program by using macros. Later the Spracklens were contacted by Hayden Books and a book was published. Commercialization When magnetic media publishing became widely available, a US Navy petty officer, Paul Lohnes, ported Sargon to the TRS-80, altering the graphics, input, and housekeeping routines but leaving the Spracklens' chess-playing algorithm intact. Paul consulted with the Spracklens, who were both living in San Diego at the time, to make the TRS-80 version an instant success with the help of Hayden Book's newly established software division: Hayden Software. Paul was not involved in further refinements to the TRS-80 version due to his reassignment to sea duty shortly after signing the deal with Hayden Software. In the early 1980s, SARGON CHESS was ported to the Nascom (by Bits & PCs, 1981), Exidy Sorcerer, and Sharp MZ 80K. A complete rewrite was necessary later for the Apple II, programmed by Kathleen's brother Gary Shannon. Both were published by Hayden Software. Improved versions The Spracklens made significant improvements on the original program and released Sargon II. J. Mishcon reviewed Sargon II in the October 1980 issue of The Space Gamer magazine, stating that the program beat him regularly on level 5, which took 40 minutes per move. He often beat the program at level 3—when it considered moves for about two minutes—and stated that "Level 0 is an idiot but responds instantly". Sargon 2.5, sold as a ROM module for the Chafitz Modular Game System, was identical to Sargon II but incorporated pondering. It received a 1641 rating at the Paul Masson tournament in June–July 1979, and 1736 at