The Streisand effect is a phenomenon whereby an attempt to hide, remove, or censor a piece of information has the unintended consequence of publicizing the information more usually facilitated by the internet. It is an example of psychological reactance, wherein once people are aware that some information is being kept from them, their motivation to access and spread it is increased, it is named after American entertainer Barbra Streisand, whose 2003 attempt to suppress photographs of her residence in Malibu, California inadvertently drew further public attention to it. Similar attempts have been made, for example, in cease-and-desist letters to suppress files and numbers. Instead of being suppressed, the information receives extensive publicity and media extensions such as videos and spoof songs being mirrored on the Internet or distributed on file-sharing networks. Mike Masnick of Techdirt coined the term in 2005 in relation to a holiday resort issuing a takedown notice to urinal.net over use of the resort's name.
How long is it going to take before lawyers realize that the simple act of trying to repress something they don't like online is to make it so that something that most people would never see is now seen by many more people? Let's call it the Streisand Effect; the term alluded to Barbra Streisand, who had sued photographer Kenneth Adelman and Pictopia.com for violation of privacy. The US$50 million lawsuit endeavored to remove an aerial photograph of Streisand's mansion from the publicly available collection of 12,000 California coastline photographs. Adelman photographed the beachfront property to document coastal erosion as part of the California Coastal Records Project, intended to influence government policymakers. Before Streisand filed her lawsuit, "Image 3850" had been downloaded from Adelman's website only six times; as a result of the case, public knowledge of the picture increased greatly. The lawsuit was dismissed and Streisand was ordered to pay Adelman's legal fees, which amounted to $155,567.
In November 2007, Tunisia blocked access to YouTube and Dailymotion after material was posted depicting Tunisian political prisoners. Activists and their supporters started to link the location of then-President Zine El Abidine Ben Ali's palace on Google Earth to videos about civil liberties in general; the Economist said this "turned a low-key human-rights story into a fashionable global campaign". The French intelligence agency DCRI's deletion of the French-language Wikipedia article about the military radio station of Pierre-sur-Haute resulted in the article temporarily becoming the most-viewed page on the French Wikipedia. A 2013 libel suit by Theodore Katsanevas against a Greek Wikipedia editor resulted in members of the project bringing the story to the attention of journalists; the government of South Africa stated their intention to ban the 2017 book The President's Keepers, detailing corruption within the government of Jacob Zuma. This caused sales of the book to spike causing the book to sell out within 24 hours before the ban would be put into effect.
This led to multiple reprints. In March 2019, California Representative Devin Nunes filed a defamation lawsuit against Twitter and three users for US$250 million in damages. One user named in the lawsuit, the parody account @DevinCow, had 1,204 followers before the lawsuit; the follower count for @DevinCow jumped to over 282,000 by the next day, climbed to over 545,000 the day after that - surpassing the number of followers of Nunes himself. In April 2007, a group of companies that used Advanced Access Content System encryption issued cease-and-desist letters demanding that the system's numerical key be removed from several high-profile websites, including Digg; this led to the key's proliferation across other sites and chat rooms in various formats, with one commentator describing it as having become "the most famous number on the Internet". Within a month, the key had been reprinted on over 280,000 pages, had been printed on T-shirts and tattoos, had appeared on YouTube in a song played over 45,000 times.
In September 2009, multi-national oil company Trafigura obtained a super-injunction to prevent The Guardian newspaper from reporting on an internal Trafigura investigation into the 2006 Ivory Coast toxic waste dump scandal, from reporting on the existence of the injunction. Using parliamentary privilege, Labour MP Paul Farrelly referred to the super-injunction in a parliamentary question, on October 12, 2009, The Guardian reported that it had been gagged from reporting on the parliamentary question, in violation of the 1689 Bill of Rights. Blogger Richard Wilson identified the blocked question as referring to the Trafigura waste dump scandal, after which The Spectator suggested the same. Not long after, Trafigura began trending on Twitter, helped along by Stephen Fry's retweeting the story to his followers. Twitter users soon tracked down all details of the case, by October 16, the super-injunction had been lifted and the report published. In November 2012, Casey Movers, a Boston moving company, threatened to sue a woman in Hingham District Court for libel in response to a negative Yelp review.
The woman's husband wrote a blog post about the situation, picked up by Techdirt and Consumerist. By the end of the week, the company was reviewed by the Better Business Bureau, which revoked its accreditation. In December 2013, YouTube user ghostlyrich uploaded video proof that his Samsung Galaxy S4 b
WikiLeaks is an international non-profit organisation that publishes secret information, news leaks, classified media provided by anonymous sources. Its website, initiated in 2006 in Iceland by the organisation Sunshine Press, claims a database of 10 million documents in 10 years since its launch. Julian Assange, an Australian Internet activist, is described as its founder and director. Since September 2018, Kristinn Hrafnsson has served as its editor-in-chief; the group has released a number of prominent document dumps. Early releases included documentation of equipment expenditures and holdings in the Afghanistan war and a report informing a corruption investigation in Kenya. In April 2010, WikiLeaks released the Collateral Murder footage from the 12 July 2007 Baghdad airstrike in which Iraqi journalists were among those killed. Other releases in 2010 included the Afghan War Diary and the "Iraq War Logs"; the latter allowed the mapping of 109,032 deaths in "significant" attacks by insurgents in Iraq, reported to Multi-National Force – Iraq, including about 15,000 that had not been published.
In 2010, WikiLeaks released the US State Department diplomatic "cables", classified cables, sent to the US State Department. In April 2011, WikiLeaks began publishing 779 secret files relating to prisoners detained in the Guantanamo Bay detention camp. During the 2016 US presidential election campaign, WikiLeaks released emails and other documents from the Democratic National Committee and from Hillary Clinton's campaign manager, John Podesta; these releases caused significant harm to the Clinton campaign, have been attributed as a potential contributing factor to her loss. The U. S. intelligence community expressed "high confidence" that the leaked emails had been hacked by Russia and supplied to WikiLeaks, while WikiLeaks denied their source was Russia or any other state. During the campaign, WikiLeaks promoted conspiracy theories about Hillary Clinton and the Democratic Party. In private conversations from November 2015 that were leaked, Julian Assange expressed a preference for a GOP victory in the 2016 election, explaining that "Dems+Media+liberals woudl form a block to reign in their worst qualities.
With Hillary in charge, GOP will be pushing for her worst qualities, dems+media+neoliberals will be mute." In private correspondence with the Trump campaign on election day, WikiLeaks encouraged the Trump campaign to contest the election results in case they lost. WikiLeaks has drawn criticism for its absence of whistleblowing on or criticism of Russia, for criticising the Panama Papers' exposé of businesses and individuals with offshore bank accounts. WikiLeaks has been criticised for inadequately curating its content and violating the personal privacy of individuals. WikiLeaks has, for instance, revealed Social Security numbers, medical information, credit card numbers and details of suicide attempts; the wikileaks.org domain name was registered on 4 October 2006. The website was established and published its first document in December 2006. WikiLeaks is represented in public by Julian Assange, described as "the heart and soul of this organisation, its founder, spokesperson, original coder, organiser and all the rest".
Sarah Harrison, Kristinn Hrafnsson and Joseph Farrell are the only other publicly known and acknowledged associates of Assange who are living. Harrison is a member of Sunshine Press Productions along with Assange and Ingi Ragnar Ingason. Gavin MacFadyen was acknowledged by Assange as a ″beloved director of WikiLeaks″ shortly after his death in 2016. WikiLeaks was established with a "wiki" communal publication method, terminated by May 2010. Original volunteers and founders were once described as a mixture of Asian dissidents, journalists and start-up company technologists from the United States, Europe and South Africa; as of June 2009, the website had more than 1,200 registered volunteers. Despite some popular confusion, related to the fact both sites use the "wiki" name and website design template, WikiLeaks and Wikipedia are not affiliated. Wikia, a for-profit corporation affiliated loosely with the Wikimedia Foundation, purchased several WikiLeaks-related domain names as a "protective brand measure" in 2007.
On 26 September 2018, it was announced that Julian Assange had appointed Kristinn Hrafnsson as editor-in-chief of WikiLeaks while the organisation's statement said Assange was remaining as its publisher. His access to the internet had been ended by his hosts in the Ecuadorian embassy in March 2019 as he had broken a commitment "not to issue messages that might interfere with other states". According to the WikiLeaks website, its goal is "to bring important news and information to the public... One of our most important activities is to publish original source material alongside our news stories so readers and historians alike can see evidence of the truth." Another of the organisation's goals is to ensure that journalists and whistleblowers are not prosecuted for emailing sensitive or classified documents. The online "drop box" is described by the WikiLeaks website as "an innovative and anonymous way for sources to leak information to journalists"; some describe WikiLeaks as journalistic organisation.
For example, in a 2013 resolution, the International Federation of Journalists, a trade union of journalists, called WikiLeaks a "new breed of media organisation" that "offers important opportunities for media organisations". Harvard professor Yochai Benkler praised WikiLeaks as a new form of journalistic enterprise, testifying at the court-martial of Chelsea Manning that "WikiLeaks did serve a
WordPress is a free and open-source content management system based on PHP & MySQL. Features include a template system, it is most associated with blogging but supports other types of web content including more traditional mailing lists and forums, media galleries, online stores. Used by more than 60 million websites, including 33.6% of the top 10 million websites as of April 2019, WordPress is the most popular website management system in use. WordPress has been used for other application domains such as pervasive display systems. WordPress was released on May 27, 2003, by its founders, Matt Mullenweg and Mike Little, as a fork of b2/cafelog; the software is released under the GPLv2 license. To function, WordPress has to be installed on a web server, either part of an Internet hosting service like WordPress.com or a computer running the software package WordPress.org in order to serve as a network host in its own right. A local computer may be used for single-user learning purposes. "WordPress is a factory that makes webpages" is a core analogy designed to clarify what WordPress is & does.
It stores your content that allows you to create & publish webpages only requiring a domain and a hosting site to work. WordPress has a web template system using a template processor, its architecture is a front controller, routing all requests for non-static URIs to a single PHP file which parses the URI and identifies the target page. This allows support for more human-readable permalinks. WordPress users may switch among different themes. Themes allow users to change the look and functionality of a WordPress website without altering the core code or site content; every WordPress website requires at least one theme to be present and every theme should be designed using WordPress standards with structured PHP, valid HTML, Cascading Style Sheets. Themes may be directly installed using the WordPress "Appearance" administration tool in the dashboard, or theme folders may be copied directly into the themes directory, for example via FTP; the PHP, HTML and CSS found in themes can be directly modified to alter theme behavior, or a theme can be a "child" theme which inherits settings from another theme and selectively overrides features.
WordPress themes are classified into two categories: free and premium. Many free themes are listed in the WordPress theme directory, premium themes are available for purchase from marketplaces and individual WordPress developers. WordPress users may create and develop their own custom themes; the free theme Underscores created by the WordPress developers has become a popular basis for new themes. WordPress' plugin architecture allows users to extend the features and functionality of a website or blog; as of February 2019, WordPress.org has 54,402 plugins available, each of which offers custom functions and features enabling users to tailor their sites to their specific needs. However, this does not include the premium plugins that are available, which may not be listed in the WordPress.org repository. These customizations range from search engine optimization, to client portals used to display private information to logged in users, to content management systems, to content displaying features, such as the addition of widgets and navigation bars.
Not all available plugins are always abreast with the upgrades and as a result they may not function properly or may not function at all. Most plugins are available through WordPress themselves, either via downloading them and installing the files manually via FTP or through the WordPress dashboard. However, many third parties offer plugins through their own websites, many of which are paid packages. Web developers who wish to develop plugins need to learn WordPress' hook system which consists of over 300 hooks divided into two categories: action hooks and filter hooks. Native applications exist for WebOS, Android, iOS, Windows Phone, BlackBerry; these applications, designed by Automattic, have options such as adding new blog posts and pages, moderating comments, replying to comments in addition to the ability to view the stats. WordPress features integrated link management. Automatic filters are included, providing standardized formatting and styling of text in posts. WordPress supports the Trackback and Pingback standards for displaying links to other sites that have themselves linked to a post or an article.
WordPress posts can be edited in HTML, using the visual editor, or using one of a number of plugins that allow for a variety of customized editing features. Prior to version 3, WordPress supported one blog per installation, although multiple concurrent copies may be run from different directories if configured to use separate database tables. WordPress Multisites was a fork of WordPress created to allow multiple blogs to exist within one installation but is able to be administered by a centralized maintainer. WordPress MU makes it possible for those with websites to host their own blogging communities, as well as control and moderate all the blogs from a single dashboard. WordPress MS adds eight new data tables for each blog; as of the release of WordPress 3, WordPress MU has merged with WordPress. B2/cafelog, more known as b2 or cafelog, was the precursor to WordPress. B2/cafelog was estimated to have been installed on 2,000 blogs as of May 2003, it was written in PHP for use with MySQL by Michel Valdrighi
ARM Advanced RISC Machine Acorn RISC Machine, is a family of reduced instruction set computing architectures for computer processors, configured for various environments. Arm Holdings develops the architecture and licenses it to other companies, who design their own products that implement one of those architectures—including systems-on-chips and systems-on-modules that incorporate memory, radios, etc, it designs cores that implement this instruction set and licenses these designs to a number of companies that incorporate those core designs into their own products. Processors that have a RISC architecture require fewer transistors than those with a complex instruction set computing architecture, which improves cost, power consumption, heat dissipation; these characteristics are desirable for light, battery-powered devices—including smartphones and tablet computers, other embedded systems. For supercomputers, which consume large amounts of electricity, ARM could be a power-efficient solution.
ARM Holdings periodically releases updates to the architecture. Architecture versions ARMv3 to ARMv7 support 32-bit arithmetic; the Thumb version supports a variable-length instruction set that provides both 32- and 16-bit instructions for improved code density. Some older cores can provide hardware execution of Java bytecodes. Released in 2011, the ARMv8-A architecture added support for a 64-bit address space and 64-bit arithmetic with its new 32-bit fixed-length instruction set. With over 100 billion ARM processors produced as of 2017, ARM is the most used instruction set architecture and the instruction set architecture produced in the largest quantity; the used Cortex cores, older "classic" cores, specialized SecurCore cores variants are available for each of these to include or exclude optional capabilities. The British computer manufacturer Acorn Computers first developed the Acorn RISC Machine architecture in the 1980s to use in its personal computers, its first ARM-based products were coprocessor modules for the BBC Micro series of computers.
After the successful BBC Micro computer, Acorn Computers considered how to move on from the simple MOS Technology 6502 processor to address business markets like the one, soon dominated by the IBM PC, launched in 1981. The Acorn Business Computer plan required that a number of second processors be made to work with the BBC Micro platform, but processors such as the Motorola 68000 and National Semiconductor 32016 were considered unsuitable, the 6502 was not powerful enough for a graphics-based user interface. According to Sophie Wilson, all the processors tested at that time performed about the same, with about a 4 Mbit/second bandwidth. After testing all available processors and finding them lacking, Acorn decided it needed a new architecture. Inspired by papers from the Berkeley RISC project, Acorn considered designing its own processor. A visit to the Western Design Center in Phoenix, where the 6502 was being updated by what was a single-person company, showed Acorn engineers Steve Furber and Sophie Wilson they did not need massive resources and state-of-the-art research and development facilities.
Wilson developed the instruction set, writing a simulation of the processor in BBC BASIC that ran on a BBC Micro with a 6502 second processor. This convinced Acorn engineers. Wilson approached Acorn's CEO, Hermann Hauser, requested more resources. Hauser assembled a small team to implement Wilson's model in hardware; the official Acorn RISC Machine project started in October 1983. They chose VLSI Technology as the silicon partner, as they were a source of ROMs and custom chips for Acorn. Wilson and Furber led the design, they implemented it with a similar efficiency ethos as the 6502. A key design goal was achieving low-latency input/output handling like the 6502; the 6502's memory access architecture had let developers produce fast machines without costly direct memory access hardware. The first samples of ARM silicon worked properly when first received and tested on 26 April 1985; the first ARM application was as a second processor for the BBC Micro, where it helped in developing simulation software to finish development of the support chips, sped up the CAD software used in ARM2 development.
Wilson subsequently rewrote BBC BASIC in ARM assembly language. The in-depth knowledge gained from designing the instruction set enabled the code to be dense, making ARM BBC BASIC an good test for any ARM emulator; the original aim of a principally ARM-based computer was achieved in 1987 with the release of the Acorn Archimedes. In 1992, Acorn once more won the Queen's Award for Technology for the ARM; the ARM2 featured 26-bit address space and 27 32-bit registers. Eight bits from the program counter register were available for other purposes; the address bus was extended to 32 bits in the ARM6, but program code still had to lie within the first 64 MB of memory in 26-bit compatibility mode, due to the reserved bits for the status flags. The ARM2 had a transistor count of just 30,000, compared to Motorola's six-year-older 68000 model with around 40,000. Much of this simplicity came from the lack of mic
A sine wave or sinusoid is a mathematical curve that describes a smooth periodic oscillation. A sine wave is a continuous wave, it is named after the function sine. It occurs in pure and applied mathematics, as well as physics, signal processing and many other fields, its most basic form as a function of time is: y = A sin = A sin where: A, the peak deviation of the function from zero. F, ordinary frequency, the number of oscillations that occur each second of time. Ω = 2πf, angular frequency, the rate of change of the function argument in units of radians per second φ, specifies where in its cycle the oscillation is at t = 0. When φ is non-zero, the entire waveform appears to be shifted in time by the amount φ /ω seconds. A negative value represents a delay, a positive value represents an advance; the sine wave is important in physics because it retains its wave shape when added to another sine wave of the same frequency and arbitrary phase and magnitude. It is the only periodic waveform; this property makes it acoustically unique.
In general, the function may have: a spatial variable x that represents the position on the dimension on which the wave propagates, a characteristic parameter k called wave number, which represents the proportionality between the angular frequency ω and the linear speed ν. The wavenumber is related to the angular frequency by:. K = ω v = 2 π f v = 2 π λ where λ is the wavelength, f is the frequency, v is the linear speed; this equation gives a sine wave for a single dimension. This could, for example, be considered the value of a wave along a wire. In two or three spatial dimensions, the same equation describes a travelling plane wave if position x and wavenumber k are interpreted as vectors, their product as a dot product. For more complex waves such as the height of a water wave in a pond after a stone has been dropped in, more complex equations are needed; this wave pattern occurs in nature, including wind waves, sound waves, light waves. A cosine wave is said to be sinusoidal, because cos = sin , a sine wave with a phase-shift of π/2 radians.
Because of this head start, it is said that the cosine function leads the sine function or the sine lags the cosine. The human ear can recognize single sine waves as sounding clear because sine waves are representations of a single frequency with no harmonics. To the human ear, a sound, made of more than one sine wave will have perceptible harmonics. Presence of higher harmonics in addition to the fundamental causes variation in the timbre, the reason why the same musical note played on different instruments sounds different. On the other hand, if the sound contains aperiodic waves along with sine waves the sound will be perceived to be noisy, as noise is characterized as being aperiodic or having a non-repetitive pattern. In 1822, French mathematician Joseph Fourier discovered that sinusoidal waves can be used as simple building blocks to describe and approximate any periodic waveform, including square waves. Fourier used it as an analytical tool in the study of waves and heat flow, it is used in signal processing and the statistical analysis of time series.
Since sine waves propagate without changing form in distributed linear systems, they are used to analyze wave propagation. Sine waves traveling in two directions in space can be represented as u = A sin When two waves having the same amplitude and frequency, traveling in opposite directions, superpose each other a standing wave pattern is created. Note that, on a plucked string, the interfering waves are the waves reflected from the fixed end
RSA is one of the first public-key cryptosystems and is used for secure data transmission. In such a cryptosystem, the encryption key is public and it is different from the decryption key, kept secret. In RSA, this asymmetry is based on the practical difficulty of the factorization of the product of two large prime numbers, the "factoring problem"; the acronym RSA is made of the initial letters of the surnames of Ron Rivest, Adi Shamir, Leonard Adleman, who first publicly described the algorithm in 1978. Clifford Cocks, an English mathematician working for the British intelligence agency Government Communications Headquarters, had developed an equivalent system in 1973, but this was not declassified until 1997. A user of RSA creates and publishes a public key based on two large prime numbers, along with an auxiliary value; the prime numbers must be kept secret. Anyone can use the public key to encrypt a message, but with published methods, if the public key is large enough, only someone with knowledge of the prime numbers can decode the message feasibly.
Breaking RSA encryption is known as the RSA problem. Whether it is as difficult as the factoring problem remains an open question. RSA is a slow algorithm, because of this, it is less used to directly encrypt user data. More RSA passes encrypted shared keys for symmetric key cryptography which in turn can perform bulk encryption-decryption operations at much higher speed; the idea of an asymmetric public-private key cryptosystem is attributed to Whitfield Diffie and Martin Hellman, who published this concept in 1976. They introduced digital signatures and attempted to apply number theory, their formulation used a shared-secret-key created from exponentiation of some number, modulo a prime number. However, they left open the problem of realizing a one-way function because the difficulty of factoring was not well-studied at the time. Ron Rivest, Adi Shamir, Leonard Adleman at the Massachusetts Institute of Technology, made several attempts over the course of a year to create a one-way function, hard to invert.
Rivest and Shamir, as computer scientists, proposed many potential functions, while Adleman, as a mathematician, was responsible for finding their weaknesses. They tried many approaches including "knapsack-based" and "permutation polynomials". For a time, they thought what they wanted to achieve was impossible due to contradictory requirements. In April 1977, they spent Passover at the house of a student and drank a good deal of Manischewitz wine before returning to their homes at around midnight. Rivest, unable to sleep, lay on the couch with a math textbook and started thinking about their one-way function, he spent the rest of the night formalizing his idea, he had much of the paper ready by daybreak. The algorithm is now known as RSA – the initials of their surnames in same order as their paper. Clifford Cocks, an English mathematician working for the British intelligence agency Government Communications Headquarters, described an equivalent system in an internal document in 1973. However, given the expensive computers needed to implement it at the time, RSA was considered to be a curiosity and, as far as is publicly known, was never deployed.
His discovery, was not revealed until 1997 due to its top-secret classification. Kid-RSA is a simplified public-key cipher published in 1997, designed for educational purposes; some people feel that learning Kid-RSA gives insight into RSA and other public-key ciphers, analogous to simplified DES. MIT was granted U. S. Patent 4,405,829 for a "Cryptographic communications system and method" that used the algorithm, on September 20, 1983. Though the patent was going to expire on September 21, 2000, the algorithm was released to the public domain by RSA Security on September 6, 2000, two weeks earlier. Since a paper describing the algorithm had been published in August 1977, prior to the December 1977 filing date of the patent application, regulations in much of the rest of the world precluded patents elsewhere and only the US patent was granted. Had Cocks's work been publicly known, a patent in the United States would not have been legal either. From the DWPI's abstract of the patent, The system includes a communications channel coupled to at least one terminal having an encoding device and to at least one terminal having a decoding device.
A message-to-be-transferred is enciphered to ciphertext at the encoding terminal by encoding the message as a number M in a predetermined set. That number is raised to a first predetermined power and computed; the remainder or residue, C, is... computed when the exponentiated number is divided by the product of two predetermined prime numbers. The RSA algorithm involves four steps: key generation, key distribution and decryption. A basic principle behind RSA is the observation that it is practical to find three large positive integers e, d and n such that with modular exponentiation for all integers m: d ≡ m and that knowing e and n or m it can be difficult to find d. In addition, for some operations it is convenient that the order of the two exponentiations can be changed and that this relation implies: e ≡ m RSA involves a public key
The TI-Nspire product line is a series of graphing calculators developed by Texas Instruments. This line includes the TI-Nspire, TI-Nspire CAS, TI-Nspire CX and TI-Nspire CX CAS. There are models aimed for the Chinese market, named the TI-Nspire CM-C, TI-Nspire CX-C, TI-Nspire CM-C CAS, TI-Nspire CX-C CAS. There is software available for Windows and Mac OS X that act in similar ways to the calculators and allow the user to create compatible files; this software either can only be used for a limited time. However, Texas Instruments provides separate software that can be used for an unlimited time without a license but only allows file transfers and not emulation of the calculator. In 2010, Texas Instruments updated the calculators to the Touchpad versions which come with the Nspire or Nspire CAS computer software and support optional rechargeable batteries. In 2011, TI announced two new models of the TI-Nspire series: Nspire CX and Nspire CX CAS; the main new features are rechargeable battery and thinner design.
In 2019, TI announced another two models of the TI-Nspire series: Nspire CX II and Nspire CX CAS II. The main new features of these new calculators are the updated operating system, new case colors, a faster processor; the TI-Nspire series is different from the previous versions of the Texas Instruments's calculators. Because TI wanted the calculator to feel more familiar for new users, the TI-Nspire uses a user interface, more similar to PCs than regular calculators, it handles documents in a similar way to PCs. The TI-Nspire was the first to be released in two models; the numeric is similar in features to the TI-84, except with a bigger and higher resolution screen and a full keyboard. The higher resolution screen makes it possible to draw graphs; the feature that the numeric lacks is the ability to solve algebraic equations such as indefinite integrals and derivatives. To fill in the gap of needing an algebraic calculator, Texas Instruments introduced the second model with the name TI-Nspire CAS, where CAS stands for Computer Algebra System.
The CAS is designed for college and university students, giving them the feature of calculating many algebraic equations like the Voyage 200 and TI-89. However, the Nspire does lack part of the ability of programming and installing additional apps that the previous models had, although a limited version of TI-BASIC is supported, along with Lua in versions. C and assembly are only possible through the jailbreaking program Ndless. Both the Nspire and Nspire CAS calculators have 16 MB of NAND Flash, 20 MB of SDRAM, 512 KB of NOR Flash; the NAND Flash is not executable. The SDRAM contains an uncompressed version of the OS, a copy of all active documents; the NOR Flash contains boot instructions for loading the operating system. Unlike all other TI graphing calculators, Nspire family models do not contain a backup battery, so when a battery is removed, the SDRAM content is deleted; this necessitates that the calculator load the operating system and file structure from the NAND Flash to the SDRAM, causing a longer loading time.
The standard TI-Nspire calculator is comparable to the TI-84 Plus in features and functionality. It contains a TI-84 Plus emulator; the target of this is secondary schools that make use of the TI-84 Plus or have textbooks that cover the TI-83 and TI-84 Plus lines, to allow them to transition to the TI-Nspire line more easily. Because the TI-Nspire lacks a QWERTY keyboard, it is acceptable for use on the PSAT, SAT, SAT II, ACT, AP, IB Exams, it should be noted, that the CAS version is not allowed on the ACT or IB. The TI-Nspire CAS calculator is capable of displaying and evaluating values symbolically, not just as floating-point numbers, it includes algebraic functions such as a symbolic differential equation solver: deSolve, the complex eigenvectors of a matrix: eigVc, as well as calculus based functions, including limits and integrals. For this reason, the TI-Nspire CAS is more comparable to the TI-89 Titanium and Voyage 200 than to other calculators, its targets are college students and universities.
Unlike the TI-Nspire, it is not compatible with the snap-in TI-84 Plus keypad. It is accepted in the AP exams but not in the ACT, IB or British GCSE and A level; the body color is grey. On 8 March 2010, Texas Instruments announced the new TI-Nspire Touchpad and TI-Nspire CAS Touchpad graphing calculators. In the United States the new calculator was listed on the TI website as a complement to the TI-Nspire with Clickpad while in some other countries, the calculator was introduced as a successor to the previous model; the calculators were released alongside the OS 2.0 update, which featured a number of updates to the user interface and new functions. The keyboards on the touchpad keypads featured a different and less crowded key layout along with the touchpad, used for navigation; the touchpad keypads are compatible with older calculators that are running OS 2.0 or newer. The new calculators that were shipped with touchpad keypads supported an optional rechargeable battery; the second generation is available in two models, the TI-Nspire Touchpad and TI-Nspire CAS Touchpad, each model has maintained the color of itself, with the normal one being white and black while the CAS is black and gray.
To reduce theft of school-owned TI-Nspire calculators, Texas Instruments introduced the EZ-Spot Teacher Packs with a bright, easy-to-spot, "school bus yellow" frame and