RNS have applications in the field of digital computer arithmetic. That is mainly due to advances in electronic engineering, fuzzy mathematics and digital computer programming. These were sensors that fed their output to the Skylab digital computer. It can also be interpreted as a hybrid analog/digital computer. The earliest programmable machines preceded the invention of the digital computer. The search for Mersenne primes was revolutionized by the introduction of the electronic digital computer. "Computational imaging" refers to any image formation method that involves a digital computer. In this position, Heller recruited such businesses as Michelin North America and Digital Computer. The term "hard copy" predates the age of the digital computer. In September 1940, Norbert Wiener approached Bush with a proposal to build a digital computer. The FLODAC Computer was built in 1964 as a proof of concept fluid digital computer. Chief among these qualities was its digital computer. Control was through a digital computer with three analog redundant channels. The applications for logic synthesis lay primarily in digital computer design. Colossus was an early binary electronic digital computer.