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🔗 The Turk
The Turk, also known as the Mechanical Turk or Automaton Chess Player (German: Schachtürke, "chess Turk"; Hungarian: A Török), was a fake chess-playing machine constructed in the late 18th century. From 1770 until its destruction by fire in 1854 it was exhibited by various owners as an automaton, though it was eventually revealed to be an elaborate hoax. Constructed and unveiled in 1770 by Wolfgang von Kempelen (Hungarian: Kempelen Farkas; 1734–1804) to impress the Empress Maria Theresa of Austria, the mechanism appeared to be able to play a strong game of chess against a human opponent, as well as perform the knight's tour, a puzzle that requires the player to move a knight to occupy every square of a chessboard exactly once.
The Turk was in fact a mechanical illusion that allowed a human chess master hiding inside to operate the machine. With a skilled operator, the Turk won most of the games played during its demonstrations around Europe and the Americas for nearly 84 years, playing and defeating many challengers including statesmen such as Napoleon Bonaparte and Benjamin Franklin. The device was later purchased in 1804 and exhibited by Johann Nepomuk Mälzel. The chess masters who secretly operated it included Johann Allgaier, Boncourt, Aaron Alexandre, William Lewis, Jacques Mouret, and William Schlumberger, but the operators within the mechanism during Kempelen's original tour remain a mystery.
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- "The Turk" | 2018-10-29 | 81 Upvotes 24 Comments
🔗 MIPS R3000
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 33.33 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 256 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 37.5 MHz for use as an I/O CPU and at 33.8 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 (48 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 1.2 μm 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 40 MHz.
- PR3400 - Developed by Performance Semiconductor, introduced in May 1991, also at up to 40 MHz. It integrated the Performance Semiconductor PR3000A and PR3010A onto a single die.
Derivatives of the R3000 for embedded applications include:
- PR31700 - A 75 MHz microcontroller from Philips Semiconductors. Fabricated in a 0.35 μm process, delivered in a 208-pin LQFP, it operated at 3.3 V and dissipated only 0.35 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 10–15 MHz CPU for use on spacecraft, it is still in use today in applications such as NASA's New Horizons space probe.
Discussed on
- "MIPS R3000" | 2019-06-20 | 37 Upvotes 59 Comments
🔗 Knuth–Morris–Pratt algorithm
In computer science, the Knuth–Morris–Pratt string-searching algorithm (or KMP algorithm) searches for occurrences of a "word" W within a main "text string" S by employing the observation that when a mismatch occurs, the word itself embodies sufficient information to determine where the next match could begin, thus bypassing re-examination of previously matched characters.
The algorithm was conceived by James H. Morris and independently discovered by Donald Knuth "a few weeks later" from automata theory. Morris and Vaughan Pratt published a technical report in 1970. The three also published the algorithm jointly in 1977. Independently, in 1969, Matiyasevich discovered a similar algorithm, coded by a two-dimensional Turing machine, while studying a string-pattern-matching recognition problem over a binary alphabet. This was the first linear-time algorithm for string matching.
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- "Knuth–Morris–Pratt algorithm" | 2014-07-05 | 117 Upvotes 47 Comments
🔗 Principle of Least Astonishment
The principle of least astonishment (POLA), also called the principle of least surprise (alternatively a "law" or "rule") applies to user interface and software design. A typical formulation of the principle, from 1984, is: "If a necessary feature has a high astonishment factor, it may be necessary to redesign the feature."
More generally, the principle means that a component of a system should behave in a way that most users will expect it to behave; the behavior should not astonish or surprise users.
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- "Principle of Least Astonishment" | 2020-05-05 | 22 Upvotes 11 Comments
🔗 Golden parachutes: Record severance payments at Wikimedia Foundation
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- "Golden parachutes: Record severance payments at Wikimedia Foundation" | 2023-05-22 | 412 Upvotes 394 Comments
🔗 Sunstone (Medieval)
The sunstone (Icelandic: sólarsteinn) is a type of mineral attested in several 13th–14th-century written sources in Iceland, one of which describes its use to locate the Sun in a completely overcast sky. Sunstones are also mentioned in the inventories of several churches and one monastery in 14th–15th-century Iceland and Germany.
A theory exists that the sunstone had polarizing attributes and was used as a navigational instrument by seafarers in the Viking Age. A stone found in 2002 off Alderney, in the wreck of a 16th-century warship, may lend evidence of the existence of sunstones as navigational devices.
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- "Sunstone (Medieval)" | 2022-12-26 | 95 Upvotes 7 Comments
🔗 Count Binface
Count Binface is a satirical perennial candidate created by the British comedian Jonathan David Harvey in 2018. He was a candidate for Uxbridge and South Ruislip in the 2019 United Kingdom general election against the then prime minister, Boris Johnson. He also stood in the London Mayoral elections in 2021 and 2024.
In earlier elections, Harvey stood as Lord Buckethead, but was forced to change the character due to a copyright dispute with the American filmmaker Todd Durham, who created Lord Buckethead for his 1984 science fiction film Hyperspace. Since then Harvey has used the forced name change to his advantage by using the platform of Binface to promote electoral participation, with the slogan, "Make your vote COUNT".
In 2019, another individual contested the Uxbridge and South Ruislip seat as Buckethead, representing the Official Monster Raving Loony Party, to which Binface said he "look[s] forward to both the hustings and to challenging [him] to take part in a receptacle-to-receptacle debate".
When Johnson resigned as an MP in 2023, Binface again stood as a candidate in the Uxbridge and South Ruislip by-election, finishing eighth of 17. Originally standing as an independent, since 2023 his affiliation has been given as Count Binface Party on ballot papers. Count Binface plans to contest the seat of current UK prime minister, Rishi Sunak, in Richmond and Northallerton, in the 2024 general election on 4 July.
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- "Count Binface" | 2024-06-25 | 56 Upvotes 41 Comments
🔗 Basel Problem
The Basel problem is a problem in mathematical analysis with relevance to number theory, first posed by Pietro Mengoli in 1650 and solved by Leonhard Euler in 1734, and read on 5 December 1735 in The Saint Petersburg Academy of Sciences. Since the problem had withstood the attacks of the leading mathematicians of the day, Euler's solution brought him immediate fame when he was twenty-eight. Euler generalised the problem considerably, and his ideas were taken up years later by Bernhard Riemann in his seminal 1859 paper "On the Number of Primes Less Than a Given Magnitude", in which he defined his zeta function and proved its basic properties. The problem is named after Basel, hometown of Euler as well as of the Bernoulli family who unsuccessfully attacked the problem.
The Basel problem asks for the precise summation of the reciprocals of the squares of the natural numbers, i.e. the precise sum of the infinite series:
The sum of the series is approximately equal to 1.644934. The Basel problem asks for the exact sum of this series (in closed form), as well as a proof that this sum is correct. Euler found the exact sum to be π2/6 and announced this discovery in 1735. His arguments were based on manipulations that were not justified at the time, although he was later proven correct, and it was not until 1741 that he was able to produce a truly rigorous proof.
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- "Basel Problem" | 2018-10-27 | 23 Upvotes 6 Comments
🔗 2000-Watt Society
The 2000-watt society is an environmental vision, first introduced in 1998 by the Swiss Federal Institute of Technology in Zürich (ETH Zurich), which pictures the average First World citizen reducing their overall average primary energy usage rate to no more than 2,000 watts (i.e. 2 kWh per hour or 48 kWh per day) by the year 2050, without lowering their standard of living.
The concept addresses not only personal or household energy use, but the total for the whole society, including embodied energy, divided by the population.
Two thousand watts is approximately the current world average rate of total primary energy use. This compared, in 2008, to averages of around 6,000 watts in western Europe, 12,000 watts in the United States, 1,500 watts in China, 1,000 watts in India, 500 watts in South Africa and only 300 watts in Bangladesh. Switzerland itself, then using an average of around 5,000 watts, was last a 2000-watt society in the 1960s.
It is further envisaged that the use of carbon-based fuels would be ultimately cut to no more than 500 watts per person within 50 to 100 years.
The vision was developed in response to concerns about climate change, energy security, and the future availability of energy supplies. It is supported by the Swiss Federal Office of Energy, the Association of Swiss Architects and Engineers, and other bodies.
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- "2000-Watt Society" | 2022-09-19 | 194 Upvotes 296 Comments
🔗 Halton Sequence
In statistics, Halton sequences are sequences used to generate points in space for numerical methods such as Monte Carlo simulations. Although these sequences are deterministic, they are of low discrepancy, that is, appear to be random for many purposes. They were first introduced in 1960 and are an example of a quasi-random number sequence. They generalize the one-dimensional van der Corput sequences.
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- "Halton Sequence" | 2023-05-30 | 47 Upvotes 9 Comments