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πŸ”— MIPS R3000

πŸ”— Computing

The R3000 is a 32-bit RISC microprocessor chipset developed by MIPS Computer Systems that implemented the MIPS I instruction set architecture (ISA). Introduced in June 1988, it was the second MIPS implementation, succeeding the R2000 as the flagship MIPS microprocessor. It operated at 20, 25 and 33.33Β MHz.

The MIPS 1 instruction set is small compared to those of the contemporary 80x86 and 680x0 architectures, encoding only more commonly used operations and supporting few addressing modes. Combined with its fixed instruction length and only three different types of instruction formats, this simplified instruction decoding and processing. It employed a 5-stage instruction pipeline, enabling execution at a rate approaching one instruction per cycle, unusual for its time.

This MIPS generation supports up to four co-processors. In addition to the CPU core, the R3000 microprocessor includes a Control Processor (CP), which contains a Translation Lookaside Buffer and a Memory Management Unit. The CP works as a coprocessor. Besides the CP, the R3000 can also support an external R3010 numeric coprocessor and two other external coprocessors.

The R3000 CPU does not include level 1 cache. Instead, its on-chip cache controller operates external data and instruction caches of up to 256Β KB each. It can access both caches during the same clock cycle.

The R3000 found much success and was used by many companies in their workstations and servers. Users included:

  • Ardent Computer
  • Digital Equipment Corporation (DEC) for their DECstation workstations and multiprocessor DECsystem servers
  • Evans & Sutherland for their Vision (ESV) series workstations
  • MIPS Computer Systems for their MIPS RISC/os Unix workstations and servers.
  • NEC for their RISC EWS4800 workstations and UP4800 servers.
  • Prime Computer
  • Pyramid Technology
  • Seiko Epson
  • Silicon Graphics for their Professional IRIS, Personal IRIS and Indigo workstations, and the multiprocessor Power Series visualization systems
  • Sony for their PlayStation and PlayStation 2 (SCPH-10000 to SCPH-700XX - clocked at 37.5Β MHz for use as an I/O CPU and at 33.8Β MHz for compatibility with PlayStation games) video game consoles, and NEWS workstations, as well as the Bemani System 573 Analog arcade unit, which runs on the R3000A.
  • Tandem Computers for their NonStop Cyclone/R and CLX/R fault-tolerant servers
  • Whitechapel Workstations for their Hitech-20 workstation
  • New Horizons Probe

The R3000 was also used as an embedded microprocessor. When advances in technology rendered it obsolete for high-performance systems, it found continued use in lower-cost designs. Companies such as LSI Logic developed derivatives of the R3000 specifically for embedded systems.

The R3000 was a further development of the R2000 with minor improvements including larger TLB and a faster bus to the external caches. The R3000 die contained 115,000 transistors and measured about 75,000 square mils (48Β mm2). MIPS was a fabless semiconductor company, so the R3000 was fabricated by MIPS partners including Integrated Device Technology (IDT), LSI Logic, NEC Corporation, Performance Semiconductor, and others. It was fabricated in a 1.2Β ΞΌm complementary metal–oxide–semiconductor (CMOS) process with two levels of aluminium interconnect.

Derivatives of the R3000 for non-embedded applications include:

  • R3000A - A further development by MIPS introduced in 1989. It operated at clock frequencies up to 40Β MHz.
  • PR3400 - Developed by Performance Semiconductor, introduced in May 1991, also at up to 40Β MHz. It integrated the Performance Semiconductor PR3000A and PR3010A onto a single die.

Derivatives of the R3000 for embedded applications include:

  • PR31700 - A 75Β MHz microcontroller from Philips Semiconductors. Fabricated in a 0.35Β ΞΌm process, delivered in a 208-pin LQFP, it operated at 3.3Β V and dissipated only 0.35Β W.
  • RISController - A family of low-end microcontrollers from IDT. Models include the R3041, R3051, R3052, and R3081.
  • TX3900 - A microcontroller from Toshiba.
  • Mongoose-V - A radiation-hardened and expanded 10–15Β MHz CPU for use on spacecraft, it is still in use today in applications such as NASA's New Horizons space probe.

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πŸ”— Penn Effect

πŸ”— Economics

The Penn effect is the economic finding that real income ratios between high and low income countries are systematically exaggerated by gross domestic product (GDP) conversion at market exchange rates. It is associated with what became the Penn World Table, and it has been a consistent econometric result since at least the 1950s.

The "Balassa–Samuelson effect" is a model cited as the principal cause of the Penn effect by neo-classical economics, as well as being a synonym of "Penn effect".

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πŸ”— Evercookie

πŸ”— Internet πŸ”— Computing πŸ”— Computing/Software πŸ”— Websites πŸ”— Websites/Computing πŸ”— Computing/Computer Security πŸ”— Computing/Websites

Evercookie is a JavaScript-based application created by Samy Kamkar that produces zombie cookies in a web browser that are intentionally difficult to delete. In 2013, a top-secret NSA document was leaked by Edward Snowden, citing Evercookie as a method of tracking Tor users.

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πŸ”— Anna Karenina Principle

πŸ”— Statistics πŸ”— Sociology

The Anna Karenina principle states that a deficiency in any one of a number of factors dooms an endeavor to failure. Consequently, a successful endeavor (subject to this principle) is one where every possible deficiency has been avoided.

The name of the principle derives from Leo Tolstoy's book Anna Karenina, which begins:

All happy families are alike; each unhappy family is unhappy in its own way.

In other words: happy families share a common set of attributes which lead to happiness, while any of a variety of attributes can cause an unhappy family. This concept has been generalized to apply to several fields of study.

In statistics, the term Anna Karenina principle is used to describe significance tests: there are any number of ways in which a dataset may violate the null hypothesis and only one in which all the assumptions are satisfied.

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πŸ”— Nanoscale Vacuum-Channel Transistor

πŸ”— Physics

A nanoscale vacuum-channel transistor (NVCT) is a theoretically visioned transistor in which the electron transport medium is a vacuum. In a traditional solid-state transistor, a semiconductor channel exists between the source and the drain, and the current flows through the semiconductor. However, in a nanoscale vacuum-channel transistor, no material exists between the source and the drain, and therefore, the current flows through the vacuum. However, experimental realization of such a transistor has not been demonstrated.

Theoretically, a vacuum-channel transistor is expected to operate faster than a traditional solid-state transistor, and have higher power output. Moreover, vacuum-channel transistors are expected to operate at higher temperature and radiation level than a traditional transistor making them suitable for space application.

The development of vacuum-channel transistors is still at a very early research stage, and there are only limited study in recent literature such as vertical field-emitter vacuum-channel transistor, gate-insulated planar electrodes vacuum-channel transistor, vertical vacuum-channel transistor, and all-around gate vacuum-channel transistor.

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πŸ”— Poppy Seed Defence

πŸ”— Medicine πŸ”— Athletics πŸ”— Food and drink πŸ”— Medicine/Toxicology πŸ”— Sports πŸ”— Horse racing

The poppy seed defence is a commonly cited reason to avoid any sanction for failing a drug test. The defence asserts that a suspect's positive result was a result of the person having consumed poppy seeds prior to taking the test. It has been recognised in medical and legal fields as a valid defence.

πŸ”— Twin Films

πŸ”— Film

Twin films are films with the same or similar plots produced and released at the same time by two different film studios. The phenomenon can result from two or more production companies investing in similar scripts at the same time, resulting in a race to distribute the films to audiences. Some attribute twin films to industrial espionage, the movement of staff between studios, or that the same screenplays are sent to several film studios before being accepted. Another possible explanation is if the films deal with topical issues, such as volcanic eruptions, reality television, terrorist attacks, or significant anniversaries, resulting in multiple discovery of the concept.

While twin films are often big budget films, a mockbuster can be made with a low budget, with similar titles, aesthetics, or theme as blockbuster films. Mockbusters are usually given more limited release and marketing, intending to take advantage of the public interest in the topic driven by the major film.

Producer Bingham Ray recalls a conversation where the screenwriter of the 2006 Truman Capote biopic Infamous phoned to announce that his script had been finished. Ray said "I know, I've got it on my desk!" before realizing that he actually had the screenplay to Capote, a biopic by a different writer.

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πŸ”— Lumpers and Splitters

πŸ”— Science πŸ”— Tree of Life

Lumpers and splitters are opposing factions in any discipline that has to place individual examples into rigorously defined categories. The lumper–splitter problem occurs when there is the desire to create classifications and assign examples to them, for example schools of literature, biological taxa and so on. A "lumper" is an individual who takes a gestalt view of a definition, and assigns examples broadly, assuming that differences are not as important as signature similarities. A "splitter" is an individual who takes precise definitions, and creates new categories to classify samples that differ in key ways.

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πŸ”— Chorded keyboard

πŸ”— Computing πŸ”— Computing/Computer hardware πŸ”— Occupational Safety and Health πŸ”— Typography

A keyset or chorded keyboard (also called a chorded keyset, chord keyboard or chording keyboard) is a computer input device that allows the user to enter characters or commands formed by pressing several keys together, like playing a "chord" on a piano. The large number of combinations available from a small number of keys allows text or commands to be entered with one hand, leaving the other hand free. A secondary advantage is that it can be built into a device (such as a pocket-sized computer or a bicycle handlebar) that is too small to contain a normal-sized keyboard.

A chorded keyboard minus the board, typically designed to be used while held in the hand, is called a keyer. Douglas Engelbart introduced the chorded keyset as a computer interface in 1968 at what is often called "The Mother of All Demos".

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πŸ”— Musaeum Clausum

Musaeum Clausum (Latin for Sealed Museum), also known as Bibliotheca abscondita, is a tract written by Sir Thomas Browne which was first published posthumously in 1684. The tract contains short sentence descriptions of supposed, rumoured or lost books, pictures, and objects. The subtitle describes the tract as an inventory of remarkable books, antiquities, pictures and rarities of several kinds, scarce or never seen by any man now living. Its date is unknown: however, an event from the year 1673 is cited.

Like his Pseudodoxia Epidemica, Musaeum Clausum is a catalogue of doubts and queries, only this time, in a style which anticipates the 20th-century Argentinian short-story writer Jorge Luis Borges, who once declared: "To write vast books is a laborious nonsense; much better is to offer a summary as if those books actually existed."

Browne however was not the first author to engage in such fantasy. The French author Rabelais, in his epic Gargantua and Pantagruel, also penned a list of imaginary and often obscene book titles in his "Library of Pantagruel", an inventory which Browne himself alludes to in his Religio Medici.

As the 17th-century Scientific Revolution progressed the popularity and growth of antiquarian collections, those claiming to house highly improbable items grew. Browne was an avid collector of antiquities and natural specimens, possessing a supposed unicorn's horn, presented to him by Arthur Dee. Browne's eldest son Edward visited the famous scholar Athanasius Kircher, founder of the Museo Kircherano at Rome in 1667, whose exhibits included an engine for attempting perpetual motion and a speaking head, which Kircher called his Oraculum Delphinium. He wrote to his father of his visit to the Jesuit priest's "closet of rarities".

The sheer volume of book-titles, pictures and objects listed in Musaeum Clausum is testimony to Browne's fertile imagination. However, his major editors, Simon Wilkin in the nineteenth century (1834) and Sir Geoffrey Keynes in the twentieth (1924), summarily dismissed it. Keynes considered its humour too erudite and "not to everyone's taste".

Browne's miscellaneous tract may also be read as a parody of the rising trend of private museum collections with their curios of doubtful origin, and perhaps also of publications such as the so-called Museum Hermeticum (1678), one of the last great anthologies of alchemical literature, with their divulging of near common-place alchemical concepts and symbols.

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