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🔗 Resistor–Transistor Logic (RTL)
Resistor–transistor logic (RTL) (sometimes also transistor–resistor logic (TRL)) is a class of digital circuits built using resistors as the input network and bipolar junction transistors (BJTs) as switching devices. RTL is the earliest class of transistorized digital logic circuit; it was succeeded by diode–transistor logic (DTL) and transistor–transistor logic (TTL).
RTL circuits were first constructed with discrete components, but in 1961 it became the first digital logic family to be produced as a monolithic integrated circuit. RTL integrated circuits were used in the Apollo Guidance Computer, whose design begun in 1961 and which first flew in 1966.
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- "Resistor–Transistor Logic (RTL)" | 2023-08-23 | 84 Upvotes 34 Comments
🔗 RIP Bob Givens, Looney Tunes and Tom and Jerry Artist
Robert Herman "Bob" Givens (March 2, 1918 – December 14, 2017) was an American animator, character designer, and layout artist. He worked for numerous animation studios during his career, including Walt Disney Animation Studios, Warner Bros. Cartoons, Hanna-Barbera, and DePatie–Freleng Enterprises, beginning his career during the late 1930s and continuing until the early 2000s. He was a frequent collaborator with director Chuck Jones, working with Jones both at Warner Bros. and Jones' own production company.
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- "RIP Bob Givens, Looney Tunes and Tom and Jerry Artist" | 2017-12-26 | 44 Upvotes 3 Comments
🔗 Coffin Texts
The Coffin Texts are a collection of ancient Egyptian funerary spells written on coffins beginning in the First Intermediate Period. They are partially derived from the earlier Pyramid Texts, reserved for royal use only, but contain substantial new material related to everyday desires, indicating a new target audience of common people. Ordinary Egyptians who could afford a coffin had access to these funerary spells and the pharaoh no longer had exclusive rights to an afterlife.
As the modern name of this collection of some 1,185 spells implies, they were mostly inscribed on Middle Kingdom coffins. They were also sometimes written on tomb walls, stelae, canopic chests, papyri and mummy masks. Due to the limited writing surfaces of some of these objects, the spells were often abbreviated, giving rise to long and short versions, some of which were later copied in the Book of the Dead.
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- "Coffin Texts" | 2019-12-21 | 21 Upvotes 4 Comments
🔗 Eagle Cash
Eagle Cash (stylized as EagleCash), and sister program EZpay, are cash management applications that use stored-value card technology to process financial transactions in "closed-loop" operating environments. The United States Department of the Treasury sponsors the programs for the U.S. Armed Forces. The Federal Reserve Bank of Boston administers the programs for the Treasury, and they are in use at approved U.S. military facilities inside and outside the continental United States. The systems use a plastic payment card, similar to a credit or debit card, which has an embedded microchip that tracks the card's balance and interfaces with encrypted card readers. This method allows soldiers to purchase goods and services at U.S. military posts and canteens, without carrying cash, or manage their personal bank accounts while on deployment or in training. The program reduces the amount of American currency required overseas, reduces theft, saves thousands of man-hours in labor, helps reduce the risk of transporting cash in combat environments, and increases security and convenience for service members. It helped reduce or eliminate the need for cash and money orders.
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- "Eagle Cash" | 2021-01-01 | 137 Upvotes 103 Comments
🔗 Cognitive Architecture
A cognitive architecture refers to both a theory about the structure of the human mind and to a computational instantiation of such a theory used in the fields of artificial intelligence (AI) and computational cognitive science. One of the main goals of a cognitive architecture is to summarize the various results of cognitive psychology in a comprehensive computer model. However, the results need to be formalized so far as they can be the basis of a computer program. The formalized models can be used to further refine a comprehensive theory of cognition, and more immediately, as a commercially usable model. Successful cognitive architectures include ACT-R (Adaptive Control of Thought - Rational) and SOAR.
The Institute for Creative Technologies defines cognitive architecture as: "hypothesis about the fixed structures that provide a mind, whether in natural or artificial systems, and how they work together – in conjunction with knowledge and skills embodied within the architecture – to yield intelligent behavior in a diversity of complex environments."
🔗 Rotterdam harbor storm barrier closes for the first time in its history
The Maeslantkering ("Maeslant barrier" in Dutch) is a storm surge barrier on the Nieuwe Waterweg, in South Holland, Netherlands. It was constructed from 1991 to 1997. As part of the Delta Works the barrier responds to water level predictions calculated by a centralized computer system called BOS. It automatically closes when Rotterdam (especially the Port of Rotterdam) is threatened by floods.
Maeslantkering has two 210-metre long barrier gates, with two 237-metre long steel trusses holding each. When closed, the barrier will protect the entire width (360 metres) of the Nieuwe Waterweg, the main waterway of Port of Rotterdam. It is one of the largest moving structures on Earth, rivalling the Green Bank Telescope in the United States and the Bagger 288 excavator in Germany.
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- "Rotterdam harbor storm barrier closes for the first time in its history" | 2023-12-21 | 38 Upvotes 16 Comments
🔗 Port Knocking
In computer networking, port knocking is a method of externally opening ports on a firewall by generating a connection attempt on a set of prespecified closed ports. Once a correct sequence of connection attempts is received, the firewall rules are dynamically modified to allow the host which sent the connection attempts to connect over specific port(s). A variant called single packet authorization (SPA) exists, where only a single "knock" is needed, consisting of an encrypted packet.
The primary purpose of port knocking is to prevent an attacker from scanning a system for potentially exploitable services by doing a port scan, because unless the attacker sends the correct knock sequence, the protected ports will appear closed.
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- "Port knocking" | 2020-05-15 | 254 Upvotes 178 Comments
🔗 Surface-conduction electron-emitter display
A surface-conduction electron-emitter display (SED) is a display technology for flat panel displays developed by a number of companies. SEDs use nanoscopic-scale electron emitters to energize colored phosphors and produce an image. In a general sense, an SED consists of a matrix of tiny cathode ray tubes, each "tube" forming a single sub-pixel on the screen, grouped in threes to form red-green-blue (RGB) pixels. SEDs combine the advantages of CRTs, namely their high contrast ratios, wide viewing angles and very fast response times, with the packaging advantages of LCD and other flat panel displays. They also use much less power than an LCD television of the same size.
After considerable time and effort in the early and mid-2000s, SED efforts started winding down in 2009 as LCD became the dominant technology. In August 2010, Canon announced they were shutting down their joint effort to develop SEDs commercially, signalling the end of development efforts. SEDs are closely related to another developing display technology, the field emission display, or FED, differing primarily in the details of the electron emitters. Sony, the main backer of FED, has similarly backed off from their development efforts.
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- "Surface-conduction electron-emitter display" | 2019-11-18 | 26 Upvotes 9 Comments
🔗 M.2
M.2, formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and associated connectors. M.2 replaces the mSATA standard, which uses the PCI Express Mini Card physical card layout and connectors. Employing a more flexible physical specification, the M.2 allows different module widths and lengths, and, paired with the availability of more advanced interfacing features, makes the M.2 more suitable than mSATA in general for solid-state storage applications, and particularly in smaller devices such as ultrabooks and tablets.
Computer bus interfaces provided through the M.2 connector are PCI Express 3.0 (up to four lanes), Serial ATA 3.0, and USB 3.0 (a single logical port for each of the latter two). It is up to the manufacturer of the M.2 host or module to select which interfaces are to be supported, depending on the desired level of host support and device type. The M.2 connector keying notches denote various purposes and capabilities of both M.2 hosts and devices. The unique key notches of M.2 modules also prevent them from being inserted into incompatible host connectors.
The M.2 specification supports NVM Express (NVMe) as the logical device interface for M.2 PCI Express SSDs, in addition to supporting legacy Advanced Host Controller Interface (AHCI) at the logical interface level. While the support for AHCI ensures software-level backward compatibility with legacy SATA devices and legacy operating systems, NVM Express is designed to fully utilize the capability of high-speed PCI Express storage devices to perform many I/O operations in parallel.
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- "M.2" | 2018-06-03 | 17 Upvotes 4 Comments
🔗 Fluidics
Fluidics, or fluidic logic, is the use of a fluid to perform analog or digital operations similar to those performed with electronics.
The physical basis of fluidics is pneumatics and hydraulics, based on the theoretical foundation of fluid dynamics. The term fluidics is normally used when devices have no moving parts, so ordinary hydraulic components such as hydraulic cylinders and spool valves are not considered or referred to as fluidic devices.
A jet of fluid can be deflected by a weaker jet striking it at the side. This provides nonlinear amplification, similar to the transistor used in electronic digital logic. It is used mostly in environments where electronic digital logic would be unreliable, as in systems exposed to high levels of electromagnetic interference or ionizing radiation.
Nanotechnology considers fluidics as one of its instruments. In this domain, effects such as fluid-solid and fluid-fluid interface forces are often highly significant. Fluidics have also been used for military applications.
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- "Fluidics" | 2018-05-24 | 37 Upvotes 14 Comments