1.
Software developer
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A software developer is a person concerned with facets of the software development process, including the research, design, programming, and testing of computer software. Other job titles which are used with similar meanings are programmer, software analyst. According to developer Eric Sink, the differences between system design, software development, and programming are more apparent, even more so that developers become systems architects, those who design the multi-leveled architecture or component interactions of a large software system. In a large company, there may be employees whose sole responsibility consists of one of the phases above. In smaller development environments, a few people or even an individual might handle the complete process. The word software was coined as a prank as early as 1953, before this time, computers were programmed either by customers, or the few commercial computer vendors of the time, such as UNIVAC and IBM. The first company founded to provide products and services was Computer Usage Company in 1955. The software industry expanded in the early 1960s, almost immediately after computers were first sold in mass-produced quantities, universities, government, and business customers created a demand for software. Many of these programs were written in-house by full-time staff programmers, some were distributed freely between users of a particular machine for no charge. Others were done on a basis, and other firms such as Computer Sciences Corporation started to grow. The computer/hardware makers started bundling operating systems, systems software and programming environments with their machines, new software was built for microcomputers, so other manufacturers including IBM, followed DECs example quickly, resulting in the IBM AS/400 amongst others. The industry expanded greatly with the rise of the computer in the mid-1970s. In the following years, it created a growing market for games, applications. DOS, Microsofts first operating system product, was the dominant operating system at the time, by 2014 the role of cloud developer had been defined, in this context, one definition of a developer in general was published, Developers make software for the world to use. The job of a developer is to crank out code -- fresh code for new products, code fixes for maintenance, code for business logic, bus factor Software Developer description from the US Department of Labor
2.
BlackBerry Limited
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QNX, a subsidiary of BlackBerry, produces automotive software. BlackBerrys software and hardware products are used worldwide by various agencies and by car makers. The company is headquartered in Waterloo, Ontario, Canada and it was founded by Mike Lazaridis and Douglas Fregin in 1984. Fregin left the company in 2007, in 1992 Lazaridis hired Jim Balsillie, and Lazaridis and Balsillie served as co-CEOs until January 22,2012. In November 2013, John S. Chen took over as CEO and his strategy is to subcontract manufacturing to Foxconn, and to focus on software technology. Research In Motion Limited was founded in March 1984 by Mike Lazaridis, at the time, Lazaridis was an engineering student at the University of Waterloo while Fregin was an engineering student at the University of Windsor. In 1990, RIM introduced the DigiSync Film KeyKode Reader, in 1991, RIM introduced the first Mobitex protocol converter. In 1992, RIM introduced the first Mobitex point-of-sale solution, a converter box that interfaced with existing point-of-sale terminal equipment to enable wireless communication. In 1993, RIM introduced the RIMGate, the first general purpose Mobitex X.25 gateway, in the same year, RIM launched Ericsson Mobidem AT and Intel wireless modem containing RIM modem firmware. In 1994, RIM introduced the first Mobitex mobile point-of-sale terminal, in the same year, RIM received the Emmy Award for Technical Innovation and the KPMG High Technology Award. In 1995, RIM introduced Freedom, the first Type II PCMCIA radio modem for Mobitex, in 1995, RIM was financed by Canadian institutional and venture capital investors through a private placement in the privately held company. A total of C$30,000,000 in pre-IPO financing was raised by the prior to its initial public offering on the Toronto Stock Exchange in January 1998 under the symbol RIM. In 1996, RIM introduced the Inter@ctive Pager, the first two-way messaging pager, the company worked with RAM Mobile Data and Ericsson to turn the Ericsson-developed Mobitex wireless data network into a two-way paging and wireless e-mail network. Pivotal in this development was the release of the Inter@ctive Pager 950, about the size of a bar of soap, this device competed against the Skytel two-way paging network developed by Motorola. In 1999, RIM introduced the BlackBerry 850 pager, the introduction of the BlackBerry set the stage for future enterprise-oriented products from the company, such as the BlackBerry 957 in April 2000, the first BlackBerry smartphone. During fiscal 1999-2001, total assets declared in the RIMs balance sheet grew eight-fold due to massive capacity expansion, the introduction of the Pearl series was highly successful, as was the subsequent Curve 8300 series and Bold 9000. Extensive carrier partnerships fuelled the expansion of BlackBerry users globally in both enterprise and consumer markets. Despite the arrival of the first Apple iPhone in 2007, BlackBerry sustained unprecedented market share growth well into 2011, the Storm sold well but suffered from mixed to poor reviews and poor customer satisfaction
3.
Unix-like
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A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell, there is no standard for defining the term, and some difference of opinion is possible as to the degree to which a given operating system or application is Unix-like. The Open Group owns the UNIX trademark and administers the Single UNIX Specification and they do not approve of the construction Unix-like, and consider it a misuse of their trademark. Other parties frequently treat Unix as a genericized trademark, in 2007, Wayne R. Gray sued to dispute the status of UNIX as a trademark, but lost his case, and lost again on appeal, with the court upholding the trademark and its ownership. Unix-like systems started to appear in the late 1970s and early 1980s, many proprietary versions, such as Idris, UNOS, Coherent, and UniFlex, aimed to provide businesses with the functionality available to academic users of UNIX. These largely displaced the proprietary clones, growing incompatibility among these systems led to the creation of interoperability standards, including POSIX and the Single UNIX Specification. Various free, low-cost, and unrestricted substitutes for UNIX emerged in the 1980s and 1990s, including 4. 4BSD, Linux, some of these have in turn been the basis for commercial Unix-like systems, such as BSD/OS and OS X. The various BSD variants are notable in that they are in fact descendants of UNIX, however, the BSD code base has evolved since then, replacing all of the AT&T code. Since the BSD variants are not certified as compliant with the Single UNIX Specification, dennis Ritchie, one of the original creators of Unix, expressed his opinion that Unix-like systems such as Linux are de facto Unix systems. Eric S. Raymond and Rob Landley have suggested there are three kinds of Unix-like systems, Genetic UNIX Those systems with a historical connection to the AT&T codebase. Most commercial UNIX systems fall into this category, so do the BSD systems, which are descendants of work done at the University of California, Berkeley in the late 1970s and early 1980s. Some of these systems have no original AT&T code but can trace their ancestry to AT&T designs. Trademark or branded UNIX These systems—largely commercial in nature—have been determined by the Open Group to meet the Single UNIX Specification and are allowed to carry the UNIX name, many ancient UNIX systems no longer meet this definition. Around 2001, Linux was given the opportunity to get a certification including free help from the POSIX chair Andrew Josey for the price of one dollar. Some non-Unix-like operating systems provide a Unix-like compatibility layer, with degrees of Unix-like functionality. IBM z/OSs UNIX System Services is sufficiently complete to be certified as trademark UNIX, cygwin and MSYS both provide a GNU environment on top of the Microsoft Windows user API, sufficient for most common open source software to be compiled and run. Subsystem for Unix-based Applications provides Unix-like functionality as a Windows NT subsystem, Windows Subsystem for Linux provides a Linux-compatible kernel interface developed by Microsoft and containing no Linux code, with Ubuntu user-mode binaries running on top of it
4.
Software release life cycle
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Usage of the alpha/beta test terminology originated at IBM. As long ago as the 1950s, IBM used similar terminology for their hardware development, a test was the verification of a new product before public announcement. B test was the verification before releasing the product to be manufactured, C test was the final test before general availability of the product. Martin Belsky, a manager on some of IBMs earlier software projects claimed to have invented the terminology, IBM dropped the alpha/beta terminology during the 1960s, but by then it had received fairly wide notice. The usage of beta test to refer to testing done by customers was not done in IBM, rather, IBM used the term field test. Pre-alpha refers to all activities performed during the project before formal testing. These activities can include requirements analysis, software design, software development, in typical open source development, there are several types of pre-alpha versions. Milestone versions include specific sets of functions and are released as soon as the functionality is complete, the alpha phase of the release life cycle is the first phase to begin software testing. In this phase, developers generally test the software using white-box techniques, additional validation is then performed using black-box or gray-box techniques, by another testing team. Moving to black-box testing inside the organization is known as alpha release, alpha software can be unstable and could cause crashes or data loss. Alpha software may not contain all of the features that are planned for the final version, in general, external availability of alpha software is uncommon in proprietary software, while open source software often has publicly available alpha versions. The alpha phase usually ends with a freeze, indicating that no more features will be added to the software. At this time, the software is said to be feature complete, Beta, named after the second letter of the Greek alphabet, is the software development phase following alpha. Software in the stage is also known as betaware. Beta phase generally begins when the software is complete but likely to contain a number of known or unknown bugs. Software in the phase will generally have many more bugs in it than completed software, as well as speed/performance issues. The focus of beta testing is reducing impacts to users, often incorporating usability testing, the process of delivering a beta version to the users is called beta release and this is typically the first time that the software is available outside of the organization that developed it. Beta version software is useful for demonstrations and previews within an organization
5.
Embedded system
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An embedded system is a computer system with a dedicated function within a larger mechanical or electrical system, often with real-time computing constraints. It is embedded as part of a device often including hardware. Embedded systems control many devices in use today. Ninety-eight percent of all microprocessors are manufactured as components of embedded systems, examples of properties of typically embedded computers when compared with general-purpose counterparts are low power consumption, small size, rugged operating ranges, and low per-unit cost. This comes at the price of limited processing resources, which make them more difficult to program. For example, intelligent techniques can be designed to power consumption of embedded systems. Modern embedded systems are based on microcontrollers, but ordinary microprocessors are also common. In either case, the processor used may be ranging from general purpose to those specialised in certain class of computations. A common standard class of dedicated processors is the signal processor. Since the embedded system is dedicated to tasks, design engineers can optimize it to reduce the size and cost of the product and increase the reliability. Some embedded systems are mass-produced, benefiting from economies of scale, complexity varies from low, with a single microcontroller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure. One of the very first recognizably modern embedded systems was the Apollo Guidance Computer, an early mass-produced embedded system was the Autonetics D-17 guidance computer for the Minuteman missile, released in 1961. When the Minuteman II went into production in 1966, the D-17 was replaced with a new computer that was the first high-volume use of integrated circuits. Since these early applications in the 1960s, embedded systems have come down in price and there has been a rise in processing power. An early microprocessor for example, the Intel 4004, was designed for calculators and other systems but still required external memory. By the early 1980s, memory, input and output system components had been integrated into the chip as the processor forming a microcontroller. Microcontrollers find applications where a computer would be too costly. A comparatively low-cost microcontroller may be programmed to fulfill the role as a large number of separate components
6.
Package manager
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A package manager deals with packages, distributions of software and data in archive files. Packages contain metadata, such as the name, description of its purpose, version number, vendor, checksum. Upon installation, metadata is stored in a package database. Package managers typically maintain a database of software dependencies and version information to prevent software mismatches and they work closely with software repositories, binary repository managers, and app stores. Package managers are designed to eliminate the need for manual installs, a software package is an archive file containing a computer program as well as necessary metadata for its deployment. The computer program can be in source code that has to be compiled, Package metadata include package description, package version, and dependencies. Package managers are charged with the task of finding, installing, maintaining or uninstalling software packages upon the users command, in these systems, complex relationships between different packages requiring different versions of libraries results in a challenge colloquially known as dependency hell. On Microsoft Windows systems, this is also called DLL hell when working with dynamically linked libraries, good package management is vital on these systems. System administrators may install and maintain software using other than package management software. For example, an administrator may download unpackaged source code, compile it. This may cause the state of the system to fall out of synchronization with the state of the package managers database. The local administrator will be required to take measures, such as manually managing some dependencies or integrating the changes into the package manager. There are tools available to ensure that locally compiled packages are integrated with the package management, particularly troublesome with software upgrades are upgrades of configuration files. There are exceptions to this that usually apply to kernel configuration, problems can be caused if the format of configuration files changes. For instance, if the old configuration file does not explicitly disable new options that should be disabled, some package managers, such as Debians dpkg, allow configuration during installation. In other situations, it is desirable to install packages with the configuration and then overwrite this configuration, for instance. This kind of pre-configured installation is also supported by dpkg, to give users more control over the kinds of software that they are allowing to be installed on their system, software is often downloaded from a number of software repositories. This process is called version pinning
7.
Intel 8088
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The Intel 8088 microprocessor is a variant of the Intel 8086. Introduced on July 1,1979, the 8088 had an 8-bit external data bus instead of the 16-bit bus of the 8086, the 16-bit registers and the one megabyte address range were unchanged, however. In fact, according to the Intel documentation, the 8086 and 8088 have the execution unit —only the bus interface unit is different. The original IBM PC was based on the 8088, the 8088 was designed in Israel, at Intels Haifa laboratory, as were a large number of Intels processors. The prefetch queue of the 8088 was shortened to four bytes, from the 8086s six bytes, and these modifications of the basic 8086 design were one of the first jobs assigned to Intels then new design office and laboratory in Haifa, Israel. Later followed the 80C88, a fully static CHMOS design, which could operate with clock speeds from 0 to 8 MHz, there were also several other, more or less similar, variants from other manufacturers. For instance, the NEC V20 was a pin compatible and slightly faster variant of the 8088, successive NEC8088 compatible processors would run at up to 16 MHz. In 1984, Commodore International signed a deal to manufacture the 8088 for use in a licensed Dynalogic Hyperion clone, when announced, the list price of the 8088 was US $124.80. The 8088 is architecturally similar to the 8086. The main difference is there are only 8 data lines instead of the 8086s 16 lines. All of the pins of the device perform the same function as they do with the 8086 with two exceptions. First, pin 34 is no longer BHE, instead it outputs a maximum mode status, SSO. Combined with the IO/M and DT/R signals, the bus cycles can be decoded, the second change is the pin that signals if a memory access or input/output access is being made has had it sense reversed. The pin on the 8088 is IO/M, on the 8086 part it is IO/M. The reason for the reversal is that it makes the 8088 compatible with the 8085. 33–1 million instructions per second. The speed of the unit and the bus of the 8086 CPU was well balanced, with a typical instruction mix. Cutting down the bus to 8 bits made it a bottleneck in the 8088. With the speed of instruction fetch reduced by 50% in the 8088 as compared to the 8086, when the queue is empty, instructions take as long to complete as they take to fetch
8.
X86
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X86 is a family of backward-compatible instruction set architectures based on the Intel 8086 CPU and its Intel 8088 variant. The term x86 came into being because the names of several successors to Intels 8086 processor end in 86, many additions and extensions have been added to the x86 instruction set over the years, almost consistently with full backward compatibility. The architecture has been implemented in processors from Intel, Cyrix, AMD, VIA and many companies, there are also open implementations. In the 1980s and early 1990s, when the 8088 and 80286 were still in common use, today, however, x86 usually implies a binary compatibility also with the 32-bit instruction set of the 80386. An 8086 system, including such as 8087 and 8089. There were also terms iRMX, iSBC, and iSBX – all together under the heading Microsystem 80, however, this naming scheme was quite temporary, lasting for a few years during the early 1980s. Today, x86 is ubiquitous in both stationary and portable computers, and is also used in midrange computers, workstations, servers. A large amount of software, including operating systems such as DOS, Windows, Linux, BSD, Solaris and macOS, functions with x86-based hardware. There have been 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 iAPX432, the Intel 960, Intel 860, however, the continuous refinement of x86 microarchitectures, circuitry and semiconductor manufacturing would make it hard to replace x86 in many segments. The table below lists processor models and model series implementing variations of the x86 instruction set, each line item is characterized by significantly improved or commercially successful processor microarchitecture designs. Such x86 implementations are seldom simple copies but often employ different internal microarchitectures as well as different solutions at the electronic, quite naturally, 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, other companies, which designed or manufactured x86 or x87 processors, include ITT Corporation, National Semiconductor, ULSI System Technology, and Weitek. Some early versions of these microprocessors had heat dissipation problems, AMD later managed to establish itself as a serious contender with the K6 set of processors, which gave way to the very successful Athlon and Opteron. There were also other contenders, such as Centaur Technology, Rise Technology, VIA Technologies energy efficient C3 and C7 processors, which were designed by the Centaur company, have been sold for many years. Centaurs newest design, the VIA Nano, is their first processor with superscalar and it was, perhaps interestingly, introduced at about the same time as Intels first in-order processor since the P5 Pentium, the Intel Atom. The instruction set architecture has twice been extended to a word size. In 1999-2003, AMD extended this 32-bit architecture to 64 bits and referred to it as x86-64 in early documents, Intel soon adopted AMDs architectural extensions under the name IA-32e, later using the name EM64T and finally using Intel 64
9.
MIPS architecture
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MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies. The early MIPS architectures were 32-bit, with 64-bit versions added later, multiple revisions of the MIPS instruction set exist, including MIPS I, MIPS II, MIPS III, MIPS IV, MIPS V, MIPS32, and MIPS64. The current revisions are MIPS32 and MIPS64, MIPS32 and MIPS64 define a control register set as well as the instruction set. Computer architecture courses in universities and technical schools often study the MIPS architecture, the architecture greatly influenced later RISC architectures such as Alpha. It used to be popular in supercomputers but all systems have dropped off the TOP500 list. Until late 2006, they were used in many of SGIs computer products. MIPS implementations were also used by Digital Equipment Corporation, NEC, Pyramid Technology, Siemens Nixdorf, in the mid to late 1990s, it was estimated that one in three RISC microprocessors produced was a MIPS implementation. Windows NT supported MIPS until the release of Windows NT4.0 SP3 in 1997, MIPS is a modular architecture supporting up to four coprocessors. In MIPS terminology, COP0 is the System Control Coprocessor, COP1 is an optional FPU, for example, in the original Playstation game console, COP0 is the System Control Coprocessor and COP2 is Geometry Transformation Engine. In the Playstation 2 game console, COP0 is a Toshiba R5900 chip, COP1 is a FPU, MIPS is a load-store architecture, meaning it only performs arithmetic and logic operations between CPU registers, requiring load/store instructions to access memory. Processors based upon the MIPS instruction set have been in production since 1988, over time several enhancements of the instruction set were made. The different revisions which have introduced are MIPS I, MIPS II, MIPS III, MIPS IV. Each revision is a superset of its predecessors, when MIPS Technologies was spun out of Silicon Graphics again in 1998, they refocused on the embedded market. At that time, this property was found to be a problem, and the architecture definition was changed to define a 32-bit MIPS32. Introduced in 1985 with the R2000, introduced in 1990 with the R6000. Introduced in 1992 in the R4000 and it adds 64-bit registers and integer instructions and a floating point square root instruction. MIPS IV is the version of the architecture. It is a superset of MIPS III and is compatible with all existing versions of MIPS, the first implementation of MIPS IV was the R8000, which was introduced in 1994
10.
PowerPC
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PowerPC is a RISC instruction set architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM. PowerPC was the cornerstone of AIMs PReP and Common Hardware Reference Platform initiatives in the 1990s and it has since become niche in personal computers, but remain popular as embedded and high-performance processors. Its use in game consoles and embedded applications provided an array of uses. In addition, PowerPC CPUs are still used in AmigaOne and third party AmigaOS4 personal computers, the history of RISC began with IBMs 801 research project, on which John Cocke was the lead developer, where he developed the concepts of RISC in 1975–78. 801-based microprocessors were used in a number of IBM embedded products, the RT was a rapid design implementing the RISC architecture. The result was the POWER instruction set architecture, introduced with the RISC System/6000 in early 1990, the original POWER microprocessor, one of the first superscalar RISC implementations, was a high performance, multi-chip design. IBM soon realized that a microprocessor was needed in order to scale its RS/6000 line from lower-end to high-end machines. Work on a one-chip POWER microprocessor, designated the RSC began, in early 1991, IBM realized its design could potentially become a high-volume microprocessor used across the industry. IBM approached Apple with the goal of collaborating on the development of a family of single-chip microprocessors based on the POWER architecture and this three-way collaboration became known as AIM alliance, for Apple, IBM, Motorola. In 1991, the PowerPC was just one facet of an alliance among these three companies. The PowerPC chip was one of joint ventures involving the three, in their efforts to counter the growing Microsoft-Intel dominance of personal computing. For Motorola, POWER looked like an unbelievable deal and it allowed them to sell a widely tested and powerful RISC CPU for little design cash on their own part. It also maintained ties with an important customer, Apple, and seemed to offer the possibility of adding IBM too, at this point Motorola already had its own RISC design in the form of the 88000 which was doing poorly in the market. Motorola was doing well with their 68000 family and the majority of the funding was focused on this, the 88000 effort was somewhat starved for resources. However, the 88000 was already in production, Data General was shipping 88000 machines, the 88000 had also achieved a number of embedded design wins in telecom applications. The result of various requirements was the PowerPC specification. The differences between the earlier POWER instruction set and PowerPC is outlined in Appendix E of the manual for PowerPC ISA v.2.02, when the first PowerPC products reached the market, they were met with enthusiasm. In addition to Apple, both IBM and the Motorola Computer Group offered systems built around the processors, Microsoft released Windows NT3.51 for the architecture, which was used in Motorolas PowerPC servers, and Sun Microsystems offered a version of its Solaris OS
11.
SuperH
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SuperH is a 32-bit reduced instruction set computing instruction set architecture developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems, as of 2015, many of the original patents for the SuperH architecture are expiring and the SH2 CPU has been reimplemented as open source hardware under the name J2. The SuperH processor core family was first developed by Hitachi in the early 1990s, Hitachi has developed a complete group of upward compatible instruction set CPU cores. The SH-1 and the SH-2 were used in the Sega Saturn and these cores have 16-bit instructions for better code density than 32-bit instructions, which was a great benefit at the time, due to the high cost of main memory. A few years later the SH-3 core was added to the SH CPU family, new features included another interrupt concept, a management unit. The SH-3 core also got a DSP extension, then called SH-3-DSP, with extended data paths for efficient DSP processing, special accumulators and a dedicated MAC-type DSP engine, this core was unifying the DSP and the RISC processor world. A derivative was also used with the original SH-2 core, between 1994 and 1996,35.1 million SuperH devices were shipped worldwide. For the Dreamcast, Hitachi developed the SH-4 architecture, superscalar instruction execution and a vector floating point unit were the highlights of this architecture. SH-4 based standard chips were introduced around 1998, the SH-3 and SH-4 architectures support both big-endian and little-endian byte ordering. Hitachi and STMicroelectronics started collaborating as early as 1997 on the design of the SH-4, in 2003, Hitachi and Mitsubishi Electric formed a joint-venture called Renesas Technology, with Hitachi controlling 55% of it. In 2004, Renesas Technology bought STMicroelectronicss share of ownership in the SuperH Inc. Renesas Technology later became Renesas Electronics, following their merger with NEC Electronics. The SH-5 design supported two modes of operation, sHcompact mode is equivalent to the user-mode instructions of the SH-4 instruction set. SHmedia mode is different, using 32-bit instructions with sixty-four 64-bit integer registers. In SHmedia mode the destination of a branch is loaded into a branch register separately from the branch instruction. This allows the processor to prefetch instructions for a branch without having to snoop the instruction stream, however, SH-5 differs because its backward compatibility mode is the 16-bit encoding rather than the 32-bit encoding. The evolution of the SuperH architecture still continues, the last of the SH-2 patents expired in 2014. At LinuxCon Japan 2015, j-core developers presented a cleanroom reimplemention of the SH-2 ISA with extensions, subsequently, a design walkthrough was presented at ELC2016. The open source BSD licensed VHDL code for the J2 core has been proven on Xilinx FPGAs and on ASICs manufactured on TSMCs 180 nm process, additional instructions are easy to add
12.
ARM architecture
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ARM, originally Acorn RISC Machine, later Advanced RISC Machine, is a family of reduced instruction set computing architectures for computer processors, configured for various environments. It also 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, a RISC-based computer design approach means processors require fewer transistors than typical complex instruction set computing x86 processors in most personal computers. This approach reduces costs, heat and power use and these characteristics are desirable for light, portable, battery-powered devices—including smartphones, laptops and tablet computers, and other embedded systems. For supercomputers, which large amounts of electricity, ARM could also be a power-efficient solution. ARM Holdings periodically releases updates to architectures and core designs, some older cores can also provide hardware execution of Java bytecodes. The ARMv8-A architecture, announced in October 2011, adds support for a 64-bit address space, with over 100 billion ARM processors produced as of 2017, ARM is the most widely used instruction set architecture in terms of quantity produced. Currently, the widely used Cortex cores, older classic cores, 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, according to Sophie Wilson, all the tested processors 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 white papers on the Berkeley RISC project, Acorn considered designing its own processor. Wilson developed the 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 they were on the right track, Wilson approached Acorns CEO, Hermann Hauser, and requested more resources. Hauser gave his approval and assembled a team to implement Wilsons model in hardware. The official Acorn RISC Machine project started in October 1983 and 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 and 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 6502s 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, Wilson subsequently rewrote BBC BASIC in ARM assembly language. The in-depth knowledge gained from designing the instruction set enabled the code to be very dense, 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 Queens Award for Technology for the ARM, the ARM2 featured a 32-bit data bus, 26-bit address space and 27 32-bit registers
13.
StrongARM
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The StrongARM is a family of computer microprocessors developed by Digital Equipment Corporation and manufactured in the late 1990s which implemented the ARM v4 instruction set architecture. It was later sold to Intel in 1997, who continued to manufacture it before replacing it with the XScale in the early 2000s, the StrongARM was a collaborative project between DEC and Advanced RISC Machines to create a faster ARM microprocessor. The StrongARM was designed to address the upper-end of the embedded market. Targets were devices such as personal digital assistants and set-top boxes. Traditionally, the division of DEC was located in Massachusetts. In order to access to the design talent in Silicon Valley, DEC opened a design center in Palo Alto. This design center was led by Dan Dobberpuhl and was the main site for the StrongARM project. Another design site which worked on the project was in Austin, Texas that was created by some ex-DEC designers returning from Apple Computer, the project was set up in 1995, and quickly delivered their first design, the SA-110. DEC agreed to sell StrongARM to Intel as part of a settlement in 1997. Intel used the StrongARM to replace their ailing line of RISC processors, the Austin design group spun off to become Alchemy Semiconductor, another start-up company designing MIPS SoCs for the hand-held market. A new StrongARM core was developed by Intel and introduced in 2000 as the XScale, the SA-110 was the first microprocessor in the StrongARM family. The first versions, operating at 100,160, and 200 MHz, were announced on 5 February 1996, when announced, samples of these versions were available, with volume production slated for mid-1996. Faster 166 and 233 MHz versions were announced on 12 September 1996, samples of these versions were available at announcement, with volume production slated for December 1996. Throughout 1996, the SA-110 was the highest performing microprocessor for portable devices, towards the end of 1996 it was a leading CPU for internet/intranet appliances and thin client systems. The SA-110s first design win was the Apple MessagePad 2000 and it was also used in a number of products including the Acorn Computers Risc PC and Eidos Optima video editing system. The SA-110s lead designers were Daniel W. Dobberpuhl, Gregory W. Hoeppner, Liam Madden, the SA-110 had a simple microarchitecture. It was a design that executed instructions in-order with a five-stage classic RISC pipeline. The microprocessor was partitioned into several blocks, the IBOX, EBOX, IMMU, DMMU, BIU, WB, the IBOX contained hardware that operated in the first two stages of the pipeline such as the program counter
14.
XScale
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XScale is a microarchitecture for central processing units initially designed by Intel implementing the ARM architecture instruction set. XScale comprises several distinct families, IXP, IXC, IOP, PXA and CE, Intel sold the PXA family to Marvell Technology Group in June 2006. Marvell then extended the brand to include processors with other microarchitectures, the XScale architecture is based on the ARMv5TE ISA without the floating point instructions. XScale uses an integer and an eight-stage memory super-pipelined microarchitecture. Intel used the StrongARM to replace its ailing line of outdated RISC processors, all the generations of XScale are 32-bit ARMv5TE processors manufactured with a 0.18 µm or 0.13 µm process and have a 32 KB data cache and a 32 KB instruction cache. First and second generation XScale multi-core processors also have a 2 KB mini data cache, products based on the 3rd generation XScale have up to 512 KB unified L2 cache. The XScale core is used in a number of microcontroller families manufactured by Intel and Marvell, there are four generations of XScale application processors, described below, PXA210/PXA25x, PXA26x, PXA27x, and PXA3xx. There are also standalone processors, the 80200 and 80219, the PXA210 was Intels entry-level XScale targeted at mobile phone applications. It was released with the PXA250 in February 2002 and comes clocked at 133 MHz and 200 MHz, the PXA25x family consists of the PXA250 and PXA255. The PXA250 was Intels first generation of XScale processors, there was a choice of three clock speeds,200 MHz,300 MHz and 400 MHz. It came out in February 2002, in March 2003, the revision C0 of the PXA250 was renamed to PXA255. The PXA26x family consists of the PXA260 and PXA261-PXA263, the PXA260 is a stand-alone processor clocked at the same frequency as the PXA25x, but features a TPBGA package which is about 53% smaller than the PXA25xs PBGA package. The PXA26x family was released in March 2003, the PXA27x family consists of the PXA270 and PXA271-PXA272 processors. This revision is an update to the XScale family of processors. The PXA270 is clocked in four different speeds,312 MHz,416 MHz,520 MHz and 624 MHz and is a processor with no packaged memory. The PXA271 can be clocked to 13,104,208 MHz or 416 MHz and has 32 MB of 16-bit stacked StrataFlash memory and 32 MB of 16-bit SDRAM in the same package. The PXA272 can be clocked to 312 MHz,416 MHz or 520 MHz and has 64 MB of 32-bit stacked StrataFlash memory. Intel also added new technologies to the PXA27x family such as, SpeedStep
15.
Kernel (operating system)
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The kernel is a computer program that is the core of a computers operating system, with complete control over everything in the system. It is the first program loaded on start-up and it handles the rest of start-up as well as input/output requests from software, translating them into data-processing instructions for the central processing unit. It handles memory and peripherals like keyboards, monitors, printers, the critical code of the kernel is usually loaded into a protected area of memory, which prevents it from being overwritten by applications or other, more minor parts of the operating system. The kernel performs its tasks, such as running processes and handling interrupts, in contrast, everything a user does is in user space, writing text in a text editor, running programs in a GUI, etc. This separation prevents user data and kernel data from interfering with other and causing instability. The kernels interface is an abstraction layer. When a process makes requests of the kernel, it is called a system call, Kernel designs differ in how they manage these system calls and resources. A monolithic kernel runs all the operating instructions in the same address space. A microkernel runs most processes in space, for modularity. The kernel takes responsibility for deciding at any time which of the running programs should be allocated to the processor or processors. Random-access memory Random-access memory is used to both program instructions and data. Typically, both need to be present in memory in order for a program to execute, often multiple programs will want access to memory, frequently demanding more memory than the computer has available. The kernel is responsible for deciding which memory each process can use, input/output devices I/O devices include such peripherals as keyboards, mice, disk drives, printers, network adapters, and display devices. The kernel allocates requests from applications to perform I/O to an appropriate device, key aspects necessary in resource management are the definition of an execution domain and the protection mechanism used to mediate the accesses to the resources within a domain. Kernels also usually provide methods for synchronization and communication between processes called inter-process communication, finally, a kernel must provide running programs with a method to make requests to access these facilities. The kernel has full access to the memory and must allow processes to safely access this memory as they require it. Often the first step in doing this is virtual addressing, usually achieved by paging and/or segmentation, virtual addressing allows the kernel to make a given physical address appear to be another address, the virtual address. This allows every program to behave as if it is the one running
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Microkernel
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In computer science, a microkernel is the near-minimum amount of software that can provide the mechanisms needed to implement an operating system. These mechanisms include low-level address space management, thread management, If the hardware provides multiple rings or CPU modes, the microkernel may be the only software executing at the most privileged level, which is generally referred to as supervisor or kernel mode. Traditional operating system functions, such as drivers, protocol stacks. In terms of the code size, as a general rule microkernels tend to be smaller than monolithic kernels. The MINIX3 microkernel, for example, has approximately 12,000 lines of code, in 1967, Regnecentralen was installing a RC4000 prototype in a Polish fertilizer plant in Puławy. The computer used a small operating system tailored for the needs of the plant. Brinch Hansen and his team became concerned with the lack of generality and reusability of the RC4000 system and they feared that each installation would require a different operating system so they started to investigate novel and more general ways of creating software for the RC4000. In 1969, their effort resulted in the completion of the RC4000 Multiprogramming System and its nucleus provided inter-process communication based on message-passing for up to 23 unprivileged processes, out of which 8 at a time were protected from one another. Besides these elementary mechanisms, it had no strategy for program execution. This strategy was to be implemented by a hierarchy of running programs in which parent processes had complete control over child processes, microkernels were first developed in the 1980s as a response to changes in the computer world, and to several challenges adapting existing mono-kernels to these new systems. New device drivers, protocol stacks, file systems and other systems were being developed all the time. This code was located in the monolithic kernel, and thus required considerable work. This would not only allow these services to be easily worked on. Moreover, it would allow entirely new operating systems to be built up on a common core, microkernels were a very hot topic in the 1980s when the first usable local area networks were being introduced. The same mechanisms that allowed the kernel to be distributed into user space also allowed the system to be distributed across network links. The first microkernels, notably Mach, proved to have disappointing performance, however, during this time the speed of computers grew greatly in relation to networking systems, and the disadvantages in performance came to overwhelm the advantages in development terms. As of 2012, the Mach-based GNU Hurd is also functional and included in testing versions of Arch Linux, although major work on microkernels had largely ended, experimenters continued development. Microkernels are closely related to exokernels, early operating system kernels were rather small, partly because computer memory was limited
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Software license
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A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law all software is copyright protected, in code as also object code form. The only exception is software in the public domain, most distributed software can be categorized according to its license type. Two common categories for software under copyright law, and therefore with licenses which grant the licensee specific rights, are proprietary software and free, unlicensed software outside the copyright protection is either public domain software or software which is non-distributed, non-licensed and handled as internal business trade secret. Contrary to popular belief, distributed unlicensed software is copyright protected. Examples for this are unauthorized software leaks or software projects which are placed on public software repositories like GitHub without specified license. As voluntarily handing software into the domain is problematic in some international law domains, there are also licenses granting PD-like rights. Therefore, the owner of a copy of software is legally entitled to use that copy of software. Hence, if the end-user of software is the owner of the respective copy, as many proprietary licenses only enumerate the rights that the user already has under 17 U. S. C. §117, and yet proclaim to take away from the user. Proprietary software licenses often proclaim to give software publishers more control over the way their software is used by keeping ownership of each copy of software with the software publisher. The form of the relationship if it is a lease or a purchase, for example UMG v. Augusto or Vernor v. Autodesk. The ownership of goods, like software applications and video games, is challenged by licensed. The Swiss based company UsedSoft innovated the resale of business software and this feature of proprietary software licenses means that certain rights regarding the software are reserved by the software publisher. Therefore, it is typical of EULAs to include terms which define the uses of the software, the most significant effect of this form of licensing is that, if ownership of the software remains with the software publisher, then the end-user must accept the software license. In other words, without acceptance of the license, the end-user may not use the software at all, one example of such a proprietary software license is the license for Microsoft Windows. The most common licensing models are per single user or per user in the appropriate volume discount level, Licensing per concurrent/floating user also occurs, where all users in a network have access to the program, but only a specific number at the same time. Another license model is licensing per dongle which allows the owner of the dongle to use the program on any computer, Licensing per server, CPU or points, regardless the number of users, is common practice as well as site or company licenses
18.
Canada
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Canada is a country in the northern half of North America. Canadas border with the United States is the worlds longest binational land border, the majority of the country has a cold or severely cold winter climate, but southerly areas are warm in summer. Canada is sparsely populated, the majority of its territory being dominated by forest and tundra. It is highly urbanized with 82 per cent of the 35.15 million people concentrated in large and medium-sized cities, One third of the population lives in the three largest cities, Toronto, Montreal and Vancouver. Its capital is Ottawa, and other urban areas include Calgary, Edmonton, Quebec City, Winnipeg. Various aboriginal peoples had inhabited what is now Canada for thousands of years prior to European colonization. Pursuant to the British North America Act, on July 1,1867, the colonies of Canada, New Brunswick and this began an accretion of provinces and territories to the mostly self-governing Dominion to the present ten provinces and three territories forming modern Canada. With the Constitution Act 1982, Canada took over authority, removing the last remaining ties of legal dependence on the Parliament of the United Kingdom. Canada is a parliamentary democracy and a constitutional monarchy, with Queen Elizabeth II being the head of state. The country is officially bilingual at the federal level and it is one of the worlds most ethnically diverse and multicultural nations, the product of large-scale immigration from many other countries. Its advanced economy is the eleventh largest in the world, relying chiefly upon its abundant natural resources, Canadas long and complex relationship with the United States has had a significant impact on its economy and culture. Canada is a country and has the tenth highest nominal per capita income globally as well as the ninth highest ranking in the Human Development Index. It ranks among the highest in international measurements of government transparency, civil liberties, quality of life, economic freedom, Canada is an influential nation in the world, primarily due to its inclusive values, years of prosperity and stability, stable economy, and efficient military. While a variety of theories have been postulated for the origins of Canada. In 1535, indigenous inhabitants of the present-day Quebec City region used the word to direct French explorer Jacques Cartier to the village of Stadacona, from the 16th to the early 18th century Canada referred to the part of New France that lay along the St. Lawrence River. In 1791, the area became two British colonies called Upper Canada and Lower Canada collectively named The Canadas, until their union as the British Province of Canada in 1841. Upon Confederation in 1867, Canada was adopted as the name for the new country at the London Conference. The transition away from the use of Dominion was formally reflected in 1982 with the passage of the Canada Act, later that year, the name of national holiday was changed from Dominion Day to Canada Day
19.
Mobile phone
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A mobile phone is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the systems of a mobile phone operator. Most modern mobile telephone services use a network architecture, and, therefore. Mobile phones which offer these and more general computing capabilities are referred to as smartphones, the first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing c.4.4 lbs. In 1983, the DynaTAC 8000x was the first commercially available mobile phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to seven billion, penetrating 100% of the global population. In first quarter of 2016, the top smartphone manufacturers were Samsung, Apple, a handheld mobile radio telephone service was envisioned in the early stages of radio engineering. In 1917, Finnish inventor Eric Tigerstedt filed a patent for a pocket-size folding telephone with a thin carbon microphone. Early predecessors of cellular phones included analog radio communications from ships, the race to create truly portable telephone devices began after World War II, with developments taking place in many countries. These 0G systems were not cellular, supported few simultaneous calls, the first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing c.4.4 lbs. The first commercial automated cellular network was launched in Japan by Nippon Telegraph and this was followed in 1981 by the simultaneous launch of the Nordic Mobile Telephone system in Denmark, Finland, Norway, and Sweden. Several other countries followed in the early to mid-1980s. These first-generation systems could support far more simultaneous calls but still used analog cellular technology, in 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. In 1991, the digital cellular technology was launched in Finland by Radiolinja on the GSM standard. This sparked competition in the sector as the new operators challenged the incumbent 1G network operators, ten years later, in 2001, the third generation was launched in Japan by NTT DoCoMo on the WCDMA standard. This was followed by 3. 5G, 3G+ or turbo 3G enhancements based on the high-speed packet access family, allowing UMTS networks to have data transfer speeds. By 2009, it had become clear that, at point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications. Consequently, the industry began looking to data-optimized fourth-generation technologies, with the promise of speed improvements up to ten-fold over existing 3G technologies
20.
Operating system
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An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require a system to function. Operating systems are found on many devices that contain a computer – from cellular phones, the dominant desktop operating system is Microsoft Windows with a market share of around 83. 3%. MacOS by Apple Inc. is in place, and the varieties of Linux is in third position. Linux distributions are dominant in the server and supercomputing sectors, other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can run one program at a time. Multi-tasking may be characterized in preemptive and co-operative types, in preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, e. g. Solaris, Linux, cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking, 32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem, a distributed operating system manages a group of distinct computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other gave rise to distributed computing, distributed computations are carried out on more than one machine. When computers in a work in cooperation, they form a distributed system. The technique is used both in virtualization and cloud computing management, and is common in large server warehouses, embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy and they are able to operate with a limited number of resources. They are very compact and extremely efficient by design, Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is a system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could run different programs in succession to speed up processing
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Monolithic kernel
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A monolithic kernel is an operating system architecture where the entire operating system is working in kernel space and is alone in supervisor mode. The monolithic model differs from other operating system architectures in that it defines a high-level virtual interface over computer hardware. A set of primitives or system calls implement all operating system such as process management, concurrency. Device drivers can be added to the kernel as modules and this modularity of the operating system is at the binary level and not at the architecture level. Modular monolithic operating systems are not to be confused with the level of modularity inherent in Server-Client operating systems which use microkernels. Practically speaking, dynamically loading modules is simply a more flexible way of handling the operating system image at runtime — as opposed to rebooting with a different operating system image, the modules allow easy extension of the operating systems capabilities as required. Dynamically loadable modules incur a small overhead when compared to building the module into the system image. Namely, an unloaded module need not be stored in random access memory
