De Re Atari (Latin for "All About Atari"), subtitled A Guide to Effective Programming, is a book written by Atari, Inc. employees in 1981 and published by the Atari Program Exchange in 1982 as an unbound, shrink-wrapped set of three-holed punched pages. It was one of the few non-software products sold by APX. Targeted at developers, it documents the advanced features of the Atari 8-bit family of home computers and includes ideas for how to use them in applications. The information in the book was not available in a single, collected source at the time of publication. The content of De Re Atari was serialized in BYTE beginning in 1981, prior to the book's publication. The release of Atari 8-bit technical details through the magazine and book quickly resulted in other sources being published, such as COMPUTE!'s First Book of Atari Graphics (1982).Atari published official documentation for the hardware and a source listing of the operating system the same year, 1982, but they were not as easily obtainable as De Re Atari and tutorials in magazines such as COMPUTE!. Following the closure of the Atari Program Exchange in late 1984, De Re Atari went out of print. Source: Wikipedia (en)