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🔗 Computing 🔗 Mathematics

The reflected binary code (RBC), also known just as reflected binary (RB) or Gray code after Frank Gray, is an ordering of the binary numeral system such that two successive values differ in only one bit (binary digit). The reflected binary code was originally designed to prevent spurious output from electromechanical switches. Today, Gray codes are widely used to facilitate error correction in digital communications such as digital terrestrial television and some cable TV systems.

🔗 Computing

Icon is a very high-level programming language featuring goal-directed execution and many facilities for managing strings and textual patterns. It is related to SNOBOL and SL5, string processing languages. Icon is not object-oriented, but an object-oriented extension called Idol was developed in 1996 which eventually became Unicon.

🔗 Computing 🔗 Computing/Computer hardware 🔗 Computing/Early computers

The IBM System/360 Model 67 (S/360-67) was an important IBM mainframe model in the late 1960s. Unlike the rest of the S/360 series, it included features to facilitate time-sharing applications, notably a Dynamic Address Translation unit, the "DAT box", to support virtual memory, 32-bit addressing and the 2846 Channel Controller to allow sharing channels between processors. The S/360-67 was otherwise compatible with the rest of the S/360 series.

🔗 Philosophy 🔗 Philosophy/Logic 🔗 Philosophy/Contemporary philosophy 🔗 Philosophy/Ancient philosophy 🔗 Philosophy/Philosophy of mind 🔗 Philosophy/Modern philosophy 🔗 Philosophy/Metaphysics 🔗 Philosophy/Analytic philosophy 🔗 Folklore

In the metaphysics of identity, the ship of Theseus is a thought experiment that raises the question of whether an object that has had all of its components replaced remains fundamentally the same object. The concept is one of the oldest in Western philosophy, having been discussed by the likes of Heraclitus and Plato by ca. 500-400 BC.

🔗 Books 🔗 Typography

The printer’s key, also known as the number line, is a line of text printed on the copyright page (often the verso of the title page, especially in English-language publishing) of books, used to indicate the print run. Publishers began this convention about the middle of the 20th century.

An example follows:

This is how the printer's key will appear in the first print run of a book. Numbers are removed with subsequent printings, so if "1" is seen then the book is the first printing of that edition. If it is the second printing then the "1" is removed, meaning that the lowest number seen will be "2".

🔗 United States 🔗 Food and drink

The National Raisin Reserve was a raisin reserve of the United States. It was created after World War II by the government in order to control raisin prices. The reserve was run by the Raisin Administrative Committee. It was enforced by means of a "marketing order". In 2015, the United States Supreme Court ruled the reserve unconstitutional and ended it.

🔗 Computing

Jensen's Device is a computer programming technique that exploits call by name. It was devised by Danish computer scientist Jørn Jensen, who worked with Peter Naur at Regnecentralen. They worked on the GIER Algol compiler, one of the earliest correct implementations of ALGOL 60. ALGOL 60 used call by name.

🔗 Computing

The Curta is a small mechanical calculator developed by Curt Herzstark. The Curta's design is a descendant of Gottfried Leibniz's Stepped Reckoner and Charles Thomas's Arithmometer, accumulating values on cogs, which are added or complemented by a stepped drum mechanism. It has an extremely compact design: a small cylinder that fits in the palm of the hand.

Curtas were considered the best portable calculators available until they were displaced by electronic calculators in the 1970s.

🔗 United States 🔗 Trains 🔗 United States/Ohio 🔗 Trains/Rapid transit 🔗 United States/Cincinnati

The Cincinnati Subway is a set of incomplete, derelict tunnels and stations for a rapid transit system beneath the streets of Cincinnati, Ohio. Although it is only a little over 2 miles in length, it is the largest abandoned subway tunnel system in the United States. Construction began in the early 1900s as an upgrade to the Cincinnati streetcar system, but was abandoned due to escalating costs, the collapse of funding amidst political bickering, and the Great Depression during the 1920s and 1930s.

In 1928, the construction of the subway system in Cincinnati was indefinitely canceled. There are no plans to revive the project.