Analog computer

An analog computer is a form of computer that uses the continuously changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved. In contrast, digital computers represent varying quantities symbolically, as their numerical values change. As an analog computer does not use discrete values, but rather continuous values, processes cannot be reliably repeated with exact equivalence, as they can with Turing machines. Analog computers do not suffer from the quantization noise inherent in digital computers, but are limited instead by analog noise.

Analog computers were widely used in scientific and industrial applications where digital computers of the time lacked sufficient performance. Analog computers can have a very wide range of complexity. Slide rules and nomographs are the simplest, while naval gunfire control computers and large hybrid digital/analog computers were among the most complicated. Systems for process control and protective relays used analog computation to perform control and protective functions.

ANALOG Computing

ANALOG Computing (an acronym for Atari Newsletter And Lots Of Games) was an American computer magazine devoted to the Atari 8-bit home computer line, published from 1981 until 1989. ANALOG had a reputation for publishing fast and smooth machine language games, whereas most listings in the other Atari magazines of the time were written in Atari BASIC. Such games were accompanied by the assembly language source code. Originally the title as printed on the cover was A.N.A.L.O.G. 400/800 Magazine, but by the eighth issue it changed to A.N.A.L.O.G. Computing. Though the dots remained in the logo, it was simply referred to as ANALOG or ANALOG Computing inside the magazine.

ANALOG was co-launched by Lee H. Pappas and Michael DesChesnes, with the first issue being January/February 1981. It was published bi-monthly until November/December 1983 and then monthly from January 1984 on. In 1988, it was sold to LFP, Inc. Then final issue was in December 1989, totaling 79 issues.

In addition to articles and reviews, ANALOG published games and other programs as type-in listings. While the programs were covered under the magazine's copyright protections, users were granted the right to type them into their computer for personal use, so long as they were not sold or copied. ("Reader Comments," ANALOG #2, page 5).