X86 is a family of instruction set architectures based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a 16-bit extension of Intel's 8-bit 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address; the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors. Many additions and extensions have been added to the x86 instruction set over the years consistently with full backward compatibility; the architecture has been implemented in processors from Intel, Cyrix, AMD, VIA and many other companies. Of those, only Intel, AMD, VIA hold x86 architectural licenses, are producing modern 64-bit designs; the term is not synonymous with IBM PC compatibility, as this implies a multitude of other computer hardware. As of 2018, the majority of personal computers and laptops sold are based on the x86 architecture, while other categories—especially high-volume mobile categories such as smartphones or tablets—are dominated by ARM.
In the 1980s and early 1990s, when the 8088 and 80286 were still in common use, the term x86 represented any 8086 compatible CPU. Today, however, x86 implies a binary compatibility with the 32-bit instruction set of the 80386; this is due to the fact that this instruction set has become something of a lowest common denominator for many modern operating systems and also because the term became common after the introduction of the 80386 in 1985. A few years after the introduction of the 8086 and 8088, Intel added some complexity to its naming scheme and terminology as the "iAPX" of the ambitious but ill-fated Intel iAPX 432 processor was tried on the more successful 8086 family of chips, applied as a kind of system-level prefix. An 8086 system, including coprocessors such as 8087 and 8089, as well as simpler Intel-specific system chips, was thereby described as an iAPX 86 system. There were terms iRMX, iSBC, iSBX – all together under the heading Microsystem 80. However, this naming scheme was quite temporary.
Although the 8086 was developed for embedded systems and small multi-user or single-user computers as a response to the successful 8080-compatible Zilog Z80, the x86 line soon grew in features and processing power. Today, x86 is ubiquitous in both stationary and portable personal computers, is used in midrange computers, workstations and most new supercomputer clusters of the TOP500 list. A large amount of software, including a large list of x86 operating systems are using x86-based hardware. Modern x86 is uncommon in embedded systems and small low power applications as well as low-cost microprocessor markets, such as home appliances and toys, lack any significant x86 presence. Simple 8-bit and 16-bit based architectures are common here, although the x86-compatible VIA C7, VIA Nano, AMD's Geode, Athlon Neo and Intel Atom are examples of 32- and 64-bit designs used in some low power and low cost segments. There have been several attempts, including by Intel itself, to end the market dominance of the "inelegant" x86 architecture designed directly from the first simple 8-bit microprocessors.
Examples of this are the iAPX 432, the Intel 960, Intel 860 and the Intel/Hewlett-Packard Itanium architecture. However, the continuous refinement of x86 microarchitectures and semiconductor manufacturing would make it hard to replace x86 in many segments. AMD's 64-bit extension of x86 and the scalability of x86 chips such as the eight-core Intel Xeon and 12-core AMD Opteron is underlining x86 as an example of how continuous refinement of established industry standards can resist the competition from new architectures; the table below lists processor models and model series implementing variations of the x86 instruction set, in chronological order. Each line item is characterized by improved or commercially successful processor microarchitecture designs. At various times, companies such as IBM, NEC, AMD, TI, STM, Fujitsu, OKI, Cyrix, Intersil, C&T, NexGen, UMC, DM&P started to design or manufacture x86 processors intended for personal computers as well as embedded systems; such x86 implementations are simple copies but employ different internal microarchitectures as well as different solutions at the electronic and physical levels.
Quite early compatible microprocessors were 16-bit, while 32-bit designs were developed much later. For the personal computer market, real quantities started to appear around 1990 with i386 and i486 compatible processors named to Intel's original chips. Other companies, which designed or manufactured x86 or x87 processors, include ITT Corporation, National Semiconductor, ULSI System Technology, Weitek. Following the pipelined i486, Intel introduced the Pentium brand name for their new set of superscalar x86 designs.
Machine code is a computer program written in machine language instructions that can be executed directly by a computer's central processing unit. Each instruction causes the CPU to perform a specific task, such as a load, a store, a jump, or an ALU operation on one or more units of data in CPU registers or memory. Machine code is a numerical language, intended to run as fast as possible, may be regarded as the lowest-level representation of a compiled or assembled computer program or as a primitive and hardware-dependent programming language. While it is possible to write programs directly in machine code, it is tedious and error prone to manage individual bits and calculate numerical addresses and constants manually. For this reason, programs are rarely written directly in machine code in modern contexts, but may be done for low level debugging, program patching, assembly language disassembly; the overwhelming majority of practical programs today are written in higher-level languages or assembly language.
The source code is translated to executable machine code by utilities such as compilers and linkers, with the important exception of interpreted programs, which are not translated into machine code. However, the interpreter itself, which may be seen as an executor or processor, performing the instructions of the source code consists of directly executable machine code. Machine code is by definition the lowest level of programming detail visible to the programmer, but internally many processors use microcode or optimise and transform machine code instructions into sequences of micro-ops, this is not considered to be a machine code per se; every processor or processor family has its own instruction set. Instructions are patterns of bits that by physical design correspond to different commands to the machine. Thus, the instruction set is specific to a class of processors using the same architecture. Successor or derivative processor designs include all the instructions of a predecessor and may add additional instructions.
A successor design will discontinue or alter the meaning of some instruction code, affecting code compatibility to some extent. Systems may differ in other details, such as memory arrangement, operating systems, or peripheral devices; because a program relies on such factors, different systems will not run the same machine code when the same type of processor is used. A processor's instruction set may have all instructions of the same length, or it may have variable-length instructions. How the patterns are organized varies with the particular architecture and also with the type of instruction. Most instructions have one or more opcode fields which specifies the basic instruction type and the actual operation and other fields that may give the type of the operand, the addressing mode, the addressing offset or index, or the actual value itself. Not all machines or individual instructions have explicit operands. An accumulator machine has a combined left operand and result in an implicit accumulator for most arithmetic instructions.
Other architectures have accumulator versions of common instructions, with the accumulator regarded as one of the general registers by longer instructions. A stack machine has all of its operands on an implicit stack. Special purpose instructions often lack explicit operands; this distinction between explicit and implicit operands is important in code generators in the register allocation and live range tracking parts. A good code optimizer can track implicit as well as explicit operands which may allow more frequent constant propagation, constant folding of registers and other code enhancements. A computer program is a list of instructions. A program's execution is done in order for the CPU, executing it to solve a specific problem and thus accomplish a specific result. While simple processors are able to execute instructions one after another, superscalar processors are capable of executing a variety of different instructions at once. Program flow may be influenced by special'jump' instructions that transfer execution to an instruction other than the numerically following one.
Conditional jumps are not depending on some condition. A much more readable rendition of machine language, called assembly language, uses mnemonic codes to refer to machine code instructions, rather than using the instructions' numeric values directly. For example, on the Zilog Z80 processor, the machine code 00000101, which causes the CPU to decrement the B processor register, would be represented in assembly language as DEC B; the MIPS architecture provides a specific example for a machine code whose instructions are always 32 bits long. The general type of instruction is given by the op field. J-type and I-type instructions are specified by op. R-type instructions include an additional field funct to determine the exact operation; the fields used in the
Couchbase Server known as Membase, is an open-source, distributed multi-model NoSQL document-oriented database software package, optimized for interactive applications. These applications may serve many concurrent users by creating, retrieving, aggregating and presenting data. In support of these kinds of application needs, Couchbase Server is designed to provide easy-to-scale key-value or JSON document access with low latency and high sustained throughput, it is designed to be clustered from a single machine to large-scale deployments spanning many machines. A version called Couchbase Lite was marketed as Couchbase Mobile combined with other software. Couchbase Server provided client protocol compatibility with memcached, but added disk persistence, data replication, live cluster reconfiguration and multitenancy with data partitioning. Membase was developed by several leaders of the memcached project, who had founded a company, NorthScale, to develop a key-value store with the simplicity and scalability of memcached, but the storage and querying capabilities of a database.
The original membase source code was contributed by NorthScale, project co-sponsors Zynga and Naver Corporation to a new project on membase.org in June 2010. On February 8, 2011, the Membase project founders and Membase, Inc. announced a merger with CouchOne with an associated project merger. The merged company was called Inc.. In January 2012, Couchbase released Couchbase Server 1.8. In September, 2012, Orbitz said. On December 2012, Couchbase Server 2.0 was released and included a new JSON document store and querying, incremental MapReduce and replication across data centers. Every Couchbase node consists of a data service, index service, query service, cluster manager component. Starting with the 4.0 release, the three services can be distributed to run on separate nodes of the cluster if needed. In the parlance of Eric Brewer’s CAP theorem, Couchbase is a CP type system meaning it provides consistency and partition tolerance, or it can be set up as an AP system with multiple clusters; the cluster manager supervises the configuration and behavior of all the servers in a Couchbase cluster.
It configures and supervises inter-node behavior like managing replication streams and re-balancing operations. It provides metric aggregation and consensus functions for the cluster, a RESTful cluster management interface; the cluster manager uses the Open Telecom Platform. Data replication within the nodes of a cluster can be controlled with several parameters. In December 2012, support was added for replication between different data centers; the data manager retrieves documents in response to data operations from applications. It asynchronously writes data to disk after acknowledging to the client. In version 1.7 and applications can optionally ensure data is written to more than one server or to disk before acknowledging a write to the client. Parameters define item ages that affect when data is persisted, how max memory and migration from main-memory to disk is handled, it supports working sets greater than a memory quota per "node" or "bucket". External systems can subscribe to filtered data streams, for example, full text search indexing, data analytics or archiving.
A document is the most basic unit of data manipulation in Couchbase Server. Documents are stored in JSON document format with no predefined schemas. Couchbase Server includes a built-in multi-threaded object-managed cache that implements memcached compatible APIs such as get, delete, prepend etc. Couchbase Server has a tail-append storage design, immune to data corruption, OOM killers or sudden loss of power. Data is written to the data file in an append-only manner, which enables Couchbase to do sequential writes for update, provide an optimized access patterns for disk I/O. A performance benchmark done by Altoros compared Couchbase Server with other technologies. Cisco Systems published a benchmark that measured the latency and throughput of Couchbase Server with a mixed workload in 2012. Couchbase Server is a packaged version of Couchbase's open source software technology and is available in a community edition without recent bug fixes with Apache 2.0 license. And an edition for commercial use.
Couchbase Server builds are available for Ubuntu, Red Hat, SUSE, Oracle Linux, Microsoft Windows and macOS operating systems. Couchbase has supported software developers' kits for the programming languages. Net, PHP, Python, C, Node.js, Go. A query language called the non-first normal form query language, N1QL, is used for manipulating the JSON data in Couchbase, just like SQL manipulates data in RDBMS, it has INSERT, UPDATE, DELETE, MERGE statements to operate on JSON data. It was announced in March 2015 as "SQL for documents"; the N1QL data model is non-first normal form with support for nested attributes and domain-oriented normalization. The N1QL data model is a proper superset and generalization of the relational model. Like Query SELECT * FROM `bucket` WHERE email LIKE "%@example.org". Getting Started with Couchbase Server. O'Reilly Media. P. 88. ISBN 978-1449331061. Ostrovsky, David.
Opera (web browser)
Opera is a web browser for Microsoft Windows, Android, iOS, macOS, Linux operating systems. Opera Ltd. is publicly listed on the NASDAQ stock exchange, with majority ownership and control belonging to Chinese Businessman Yahui Zhou, creator of Beijing Kunlun Tech which specialises in mobile games and cybersecurity specialist Qihoo 360. Opera is a Chromium-based browser using the Blink layout engine, it differentiates itself because of other features. Opera was conceived at Telenor as a research project in 1994 and was bought by Opera Software in 1995, it had its own proprietary Presto layout engine. The Presto versions of Opera received many awards, but Presto development ended after the big transition to Chromium in 2013. There are three mobile versions called Opera Mobile, Opera Touch and Opera Mini. Opera began in 1994 as a research project at Telenor, the largest Norwegian telecommunications company. In 1995, it branched out into a separate company named Opera Software. Opera was first publicly released in 1996 with version 2.10.
In an attempt to capitalize on the emerging market for Internet-connected handheld devices, a project to port Opera to mobile device platforms was started in 1998. Opera 4.0, released in 2000, included a new cross-platform core that facilitated the creation of editions of Opera for multiple operating systems and platforms. Up to this point, Opera had to be purchased after the trial period ended. Version 5.0 saw the end of this requirement. Instead, Opera became ad-sponsored. Versions of Opera gave the user the choice of seeing banner ads or targeted text advertisements from Google. With version 8.5 the advertisements were removed and the primary financial support for the browser came through revenue from Google. Among the new features introduced in version 9.1 was fraud protection using technology from GeoTrust, a digital certificate provider, PhishTank, an organization that tracks known phishing web sites. This feature was further improved and expanded in version 9.5, when GeoTrust was replaced with Netcraft, malware protection from Haute Secure was added.
Many distinctive Opera features of the previous versions were dropped, Opera Mail was separated into a standalone application derived from Opera 12. In November 2016, the original Norwegian owner of Opera sold his stake in the business to a Chinese consortium under the name Golden Brick Capital Private Equity Fund I Limited Partnership for $600 million. An earlier deal was not approved by regulators. In January 2017, the source code of Opera 12.15 was leaked. To demonstrate how radically different a browser could look, Opera Neon, dubbed a "concept browser", was released in January 2017. PC World compared it to demo models that automakers and hardware vendors release to show their visions of the future. Instead of a Speed Dial, it displays the accessed websites in resemblance to a desktop with computer icons scattered all over it in artistic formation. Opera has originated features adopted by other web browsers, including Speed Dial, pop-up blocking, re-opening closed pages, private browsing, tabbed browsing.
Opera includes a download manager. Opera has "Speed Dial", which allows the user to add an unlimited number of pages shown in thumbnail form in a page displayed when a new tab is opened. Speed Dial allows the user to more navigate to the selected web pages, it is possible to control some aspects of the browser using the keyboard shortcuts. Page zooming allows text and other content such as Adobe Flash Player, Java platform and Scalable Vector Graphics to be increased or decreased in size to help those with impaired vision. Opera Software claims that when the Opera Turbo mode is enabled, the compression servers compress requested web pages by up to 50%, depending upon the content, before sending them to the users; this process reduces the amount of data transferred and is useful for crowded or slow network connections, making web pages load faster or when there are costs dependent on the total amount of data usage. This technique is used in Opera Mini for mobile devices and smartwatches. One security feature is the option to delete private data, such as HTTP cookies, browsing history
Google LLC is an American multinational technology company that specializes in Internet-related services and products, which include online advertising technologies, search engine, cloud computing and hardware. It is considered one of the Big Four technology companies, alongside Amazon and Facebook. Google was founded in 1998 by Larry Page and Sergey Brin while they were Ph. D. students at Stanford University in California. Together they own about 14 percent of its shares and control 56 percent of the stockholder voting power through supervoting stock, they incorporated Google as a held company on September 4, 1998. An initial public offering took place on August 19, 2004, Google moved to its headquarters in Mountain View, nicknamed the Googleplex. In August 2015, Google announced plans to reorganize its various interests as a conglomerate called Alphabet Inc. Google is Alphabet's leading subsidiary and will continue to be the umbrella company for Alphabet's Internet interests. Sundar Pichai was appointed CEO of Google.
The company's rapid growth since incorporation has triggered a chain of products and partnerships beyond Google's core search engine. It offers services designed for work and productivity, email and time management, cloud storage, instant messaging and video chat, language translation and navigation, video sharing, note-taking, photo organizing and editing; the company leads the development of the Android mobile operating system, the Google Chrome web browser, Chrome OS, a lightweight operating system based on the Chrome browser. Google has moved into hardware. Google has experimented with becoming an Internet carrier. Google.com is the most visited website in the world. Several other Google services figure in the top 100 most visited websites, including YouTube and Blogger. Google is the most valuable brand in the world as of 2017, but has received significant criticism involving issues such as privacy concerns, tax avoidance, antitrust and search neutrality. Google's mission statement is "to organize the world's information and make it universally accessible and useful".
The companies unofficial slogan "Don't be evil" was removed from the company's code of conduct around May 2018. Google began in January 1996 as a research project by Larry Page and Sergey Brin when they were both PhD students at Stanford University in Stanford, California. While conventional search engines ranked results by counting how many times the search terms appeared on the page, the two theorized about a better system that analyzed the relationships among websites, they called this new technology PageRank. Page and Brin nicknamed their new search engine "BackRub", because the system checked backlinks to estimate the importance of a site, they changed the name to Google. The domain name for Google was registered on September 15, 1997, the company was incorporated on September 4, 1998, it was based in the garage of a friend in California. Craig Silverstein, a fellow PhD student at Stanford, was hired as the first employee. Google was funded by an August 1998 contribution of $100,000 from Andy Bechtolsheim, co-founder of Sun Microsystems.
Google received money from three other angel investors in 1998: Amazon.com founder Jeff Bezos, Stanford University computer science professor David Cheriton, entrepreneur Ram Shriram. Between these initial investors and family Google raised around 1 million dollars, what allowed them to open up their original shop in Menlo Park, California After some additional, small investments through the end of 1998 to early 1999, a new $25 million round of funding was announced on June 7, 1999, with major investors including the venture capital firms Kleiner Perkins and Sequoia Capital. In March 1999, the company moved its offices to Palo Alto, home to several prominent Silicon Valley technology start-ups; the next year, Google began selling advertisements associated with search keywords against Page and Brin's initial opposition toward an advertising-funded search engine. To maintain an uncluttered page design, advertisements were text-based. In June 2000, it was announced that Google would become the default search engine provider for Yahoo!, one of the most popular websites at the time, replacing Inktomi.
In 2003, after outgrowing two other locations, the company leased an office complex from Silicon Graphics, at 1600 Amphitheatre Parkway in Mountain View, California. The complex became known as the Googleplex, a play on the word googolplex, the number one followed by a googol zeroes. Three years Google bought the property from SGI for $319 million. By that time, the name "Google
The Financial Times is an English-language international daily newspaper owned by Nikkei Inc, headquartered in London, with a special emphasis on business and economic news. The paper was founded in 1888 by James Sheridan and Horatio Bottomley, merged in 1945 with its closest rival, the Financial News; the Financial Times has over 740,000 digital subscribers. On 23 July 2015, Nikkei Inc. agreed to buy the Financial Times from Pearson for £844m and the acquisition was completed on 30 November 2015. The FT was launched as the London Financial Guide on 10 January 1888, renaming itself the Financial Times on 13 February the same year. Describing itself as the friend of "The Honest Financier, the Bona Fide Investor, the Respectable Broker, the Genuine Director, the Legitimate Speculator", it was a four-page journal; the readership was the financial community of the City of London, its only rival being the older and more daring Financial News. On 2 January 1893 the FT began printing on light salmon-pink paper to distinguish it from the named Financial News: at the time it was cheaper to print on unbleached paper, but nowadays it is more expensive as the paper has to be dyed specially.
After 57 years of rivalry the Financial Times and the Financial News were merged in 1945 by Brendan Bracken to form a single six-page newspaper. The Financial Times brought a higher circulation while the Financial News provided much of the editorial talent; the Lex column was introduced from Financial News. Pearson bought the paper in 1957. Over the years the paper grew in size and breadth of coverage, it established correspondents in cities around the world, reflecting a renewed impetus in the world economy towards globalisation. As cross-border trade and capital flows increased during the 1970s, the FT began international expansion, facilitated by developments in technology and the growing acceptance of English as the international language of business. On 1 January 1979 the first FT was printed in Frankfurt. Since with increased international coverage, the FT has become a global newspaper, printed in 22 locations with five international editions to serve the UK, continental Europe, the U. S.
Asia and the Middle East. The European edition is distributed in continental Africa, it is printed Monday to Saturday at five centres across Europe reporting on matters concerning the European Union, the Euro and European corporate affairs. In 1994 FT launched a luxury lifestyle magazine. In 2009 it launched a standalone website for the magazine. On 13 May 1995 the Financial Times group made its first foray into the online world with the launch of FT.com. This provided a summary of news from around the globe, supplemented in February 1996 with stock price coverage; the site was funded by advertising and contributed to the online advertising market in the UK in the late 1990s. Between 1997 and 2000 the site underwent several revamps and changes of strategy, as the FT Group and Pearson reacted to changes online. FT introduced subscription services in 2002. FT.com is one of the few UK news sites funded by individual subscription. In 1997 the FT launched a U. S. edition, printed in New York, Los Angeles, San Francisco, Atlanta and Washington, D.
C. although the newspaper was first printed outside New York City in 1985. In September 1998 the FT became the first UK-based newspaper to sell more copies internationally than within the UK. In 2000 the Financial Times started publishing a German-language edition, Financial Times Deutschland, with a news and editorial team based in Hamburg, its initial circulation in 2003 was 90,000. It was a joint venture with a German publishing firm, Gruner + Jahr. In January 2008 the FT sold its 50% stake to its German partner. FT Deutschland never made a profit and is said to have accumulated losses of €250 million over 12 years, it closed on 7 December 2012. The Financial Times launched a new weekly supplement for the fund management industry on 4 February 2002. FT fund management was and still is distributed with the paper every Monday. FTfm is the world's largest-circulation fund management title. Since 2005 the FT has sponsored the annual"Financial Times" and Goldman Sachs Business Book of the Year Award.
On 23 April 2007 the FT unveiled a "refreshed" version of the newspaper and introduced a new slogan, "We Live in Financial Times."In 2007 the FT pioneered a metered paywall, which lets visitors to its site read a limited number of free articles during any one month before asking them to pay. Four years the FT launched its HTML5 mobile internet app. Smartphones and tablets now drive 19 % of traffic to FT.com. In 2012 the number of digital subscribers surpassed the circulation of the newspaper for the first time and the FT drew half of its revenue from subscriptions rather than advertising. Since 2010 the FT has been available on Bloomberg Terminal. Since 2013 the FT has been available on Wisers platform. In 2016, the Financial Times acquired a controlling stake in Alpha Grid, a London-based media company specialising in the development and production of quality branded content across a range of channels, including broadcast, digital and events. In 2018, the Financial Times acquired a controlling stake in Longitude, a specialist provider of thought leadership and research services to a multinational corporate and institutional client base.
This investment builds on the Financial Times’ recent growth in sev