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.
IBM
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International Business Machines Corporation is an American multinational technology company headquartered in Armonk, New York, United States, with operations in over 170 countries. The company originated in 1911 as the Computing-Tabulating-Recording Company and was renamed International Business Machines in 1924, IBM manufactures and markets computer hardware, middleware and software, and offers hosting and consulting services in areas ranging from mainframe computers to nanotechnology. IBM is also a research organization, holding the record for most patents generated by a business for 24 consecutive years. IBM has continually shifted its business mix by exiting commoditizing markets and focusing on higher-value, also in 2014, IBM announced that it would go fabless, continuing to design semiconductors, but offloading manufacturing to GlobalFoundries. Nicknamed Big Blue, IBM is one of 30 companies included in the Dow Jones Industrial Average and one of the worlds largest employers, with nearly 380,000 employees. Known as IBMers, IBM employees have been awarded five Nobel Prizes, six Turing Awards, ten National Medals of Technology, in the 1880s, technologies emerged that would ultimately form the core of what would become International Business Machines. On June 16,1911, their four companies were amalgamated in New York State by Charles Ranlett Flint forming a fifth company, the Computing-Tabulating-Recording Company based in Endicott, New York. The five companies had 1,300 employees and offices and plants in Endicott and Binghamton, New York, Dayton, Ohio, Detroit, Michigan, Washington, D. C. and Toronto. They manufactured machinery for sale and lease, ranging from commercial scales and industrial time recorders, meat and cheese slicers, to tabulators and punched cards. Thomas J. Watson, Sr. fired from the National Cash Register Company by John Henry Patterson, called on Flint and, Watson joined CTR as General Manager then,11 months later, was made President when court cases relating to his time at NCR were resolved. Having learned Pattersons pioneering business practices, Watson proceeded to put the stamp of NCR onto CTRs companies and his favorite slogan, THINK, became a mantra for each companys employees. During Watsons first four years, revenues more than doubled to $9 million, Watson had never liked the clumsy hyphenated title of the CTR and in 1924 chose to replace it with the more expansive title International Business Machines. By 1933 most of the subsidiaries had been merged into one company, in 1937, IBMs tabulating equipment enabled organizations to process unprecedented amounts of data, its clients including the U. S. During the Second World War the company produced small arms for the American war effort, in 1949, Thomas Watson, Sr. created IBM World Trade Corporation, a subsidiary of IBM focused on foreign operations. In 1952, he stepped down after almost 40 years at the company helm, in 1957, the FORTRAN scientific programming language was developed. In 1961, IBM developed the SABRE reservation system for American Airlines, in 1963, IBM employees and computers helped NASA track the orbital flight of the Mercury astronauts. A year later it moved its headquarters from New York City to Armonk. The latter half of the 1960s saw IBM continue its support of space exploration, on April 7,1964, IBM announced the first computer system family, the IBM System/360
3.
Programming language
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A programming language is a formal computer language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to programs to control the behavior of a machine or to express algorithms. From the early 1800s, programs were used to direct the behavior of such as Jacquard looms. Thousands of different programming languages have created, mainly in the computer field. Many programming languages require computation to be specified in an imperative form while other languages use forms of program specification such as the declarative form. The description of a language is usually split into the two components of syntax and semantics. Some languages are defined by a document while other languages have a dominant implementation that is treated as a reference. Some languages have both, with the language defined by a standard and extensions taken from the dominant implementation being common. A programming language is a notation for writing programs, which are specifications of a computation or algorithm, some, but not all, authors restrict the term programming language to those languages that can express all possible algorithms. For example, PostScript programs are created by another program to control a computer printer or display. More generally, a language may describe computation on some, possibly abstract. It is generally accepted that a specification for a programming language includes a description, possibly idealized. In most practical contexts, a programming language involves a computer, consequently, abstractions Programming languages usually contain abstractions for defining and manipulating data structures or controlling the flow of execution. Expressive power The theory of computation classifies languages by the computations they are capable of expressing, all Turing complete languages can implement the same set of algorithms. ANSI/ISO SQL-92 and Charity are examples of languages that are not Turing complete, markup languages like XML, HTML, or troff, which define structured data, are not usually considered programming languages. Programming languages may, however, share the syntax with markup languages if a computational semantics is defined, XSLT, for example, is a Turing complete XML dialect. Moreover, LaTeX, which is used for structuring documents. The term computer language is used interchangeably with programming language
4.
C (programming language)
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C was originally developed by Dennis Ritchie between 1969 and 1973 at Bell Labs, and used to re-implement the Unix operating system. C has been standardized by the American National Standards Institute since 1989, C is an imperative procedural language. Therefore, C was useful for applications that had formerly been coded in assembly language. Despite its low-level capabilities, the language was designed to encourage cross-platform programming, a standards-compliant and portably written C program can be compiled for a very wide variety of computer platforms and operating systems with few changes to its source code. The language has become available on a wide range of platforms. In C, all code is contained within subroutines, which are called functions. Function parameters are passed by value. Pass-by-reference is simulated in C by explicitly passing pointer values, C program source text is free-format, using the semicolon as a statement terminator and curly braces for grouping blocks of statements. The C language also exhibits the characteristics, There is a small, fixed number of keywords, including a full set of flow of control primitives, for, if/else, while, switch. User-defined names are not distinguished from keywords by any kind of sigil, There are a large number of arithmetical and logical operators, such as +, +=, ++, &, ~, etc. More than one assignment may be performed in a single statement, function return values can be ignored when not needed. Typing is static, but weakly enforced, all data has a type, C has no define keyword, instead, a statement beginning with the name of a type is taken as a declaration. There is no function keyword, instead, a function is indicated by the parentheses of an argument list, user-defined and compound types are possible. Heterogeneous aggregate data types allow related data elements to be accessed and assigned as a unit, array indexing is a secondary notation, defined in terms of pointer arithmetic. Unlike structs, arrays are not first-class objects, they cannot be assigned or compared using single built-in operators, There is no array keyword, in use or definition, instead, square brackets indicate arrays syntactically, for example month. Enumerated types are possible with the enum keyword and they are not tagged, and are freely interconvertible with integers. Strings are not a data type, but are conventionally implemented as null-terminated arrays of characters. Low-level access to memory is possible by converting machine addresses to typed pointers
5.
Unix
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Among these is Apples macOS, which is the Unix version with the largest installed base as of 2014. Many Unix-like operating systems have arisen over the years, of which Linux is the most popular, Unix was originally meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmer users. The system grew larger as the system started spreading in academic circles, as users added their own tools to the system. Unix was designed to be portable, multi-tasking and multi-user in a time-sharing configuration and these concepts are collectively known as the Unix philosophy. By the early 1980s users began seeing Unix as a universal operating system. Under Unix, the system consists of many utilities along with the master control program. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space, the microkernel concept was introduced in an effort to reverse the trend towards larger kernels and return to a system in which most tasks were completed by smaller utilities. In an era when a standard computer consisted of a disk for storage and a data terminal for input and output. However, modern systems include networking and other new devices, as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, and semaphores. In microkernel implementations, functions such as network protocols could be moved out of the kernel, Multics introduced many innovations, but had many problems. Frustrated by the size and complexity of Multics but not by the aims and their last researchers to leave Multics, Ken Thompson, Dennis Ritchie, M. D. McIlroy, and J. F. Ossanna, decided to redo the work on a much smaller scale. The name Unics, a pun on Multics, was suggested for the project in 1970. Peter H. Salus credits Peter Neumann with the pun, while Brian Kernighan claims the coining for himself, in 1972, Unix was rewritten in the C programming language. Bell Labs produced several versions of Unix that are referred to as Research Unix. In 1975, the first source license for UNIX was sold to faculty at the University of Illinois Department of Computer Science, UIUC graduate student Greg Chesson was instrumental in negotiating the terms of this license. During the late 1970s and early 1980s, the influence of Unix in academic circles led to adoption of Unix by commercial startups, including Sequent, HP-UX, Solaris, AIX. In the late 1980s, AT&T Unix System Laboratories and Sun Microsystems developed System V Release 4, in the 1990s, Unix-like systems grew in popularity as Linux and BSD distributions were developed through collaboration by a worldwide network of programmers
6.
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
7.
Workstation
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A workstation is a special computer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are connected to a local area network. Workstations offered higher performance than mainstream personal computers, especially with respect to CPU and graphics, memory capacity, and multitasking capability. Typically, the factor is that of a desktop computer, consist of a high resolution display, a keyboard and a mouse at a minimum. Workstations were the first segment of the market to present advanced accessories. The increasing capabilities of mainstream PCs in the late 1990s have blurred the lines somewhat with technical/scientific workstations, perhaps the first computer that might qualify as a workstation was the IBM1620, a small scientific computer designed to be used interactively by a single person sitting at the console. One peculiar feature of the machine was that it lacked any actual arithmetic circuitry, to perform addition, it required a memory-resident table of decimal addition rules. This saved on the cost of logic circuitry, enabling IBM to make it inexpensive, the machine was code-named CADET and rented initially for $1000 a month. In 1965, IBM introduced the IBM1130 scientific computer, which was meant as the successor to the 1620, both of these systems came with the ability to run programs written in Fortran and other languages. Both the 1620 and the 1130 were built into roughly desk-sized cabinets, both were available with add-on disk drives, printers, and both paper-tape and punched-card I/O. A console typewriter for direct interaction was standard on each, early examples of workstations were generally dedicated minicomputers, a system designed to support a number of users would instead be reserved exclusively for one person. A notable example was the PDP-8 from Digital Equipment Corporation, regarded to be the first commercial minicomputer, Lisp Machines were commercialized beginning 1980 by companies like Symbolics, Lisp Machines, Texas Instruments and Xerox. The first computer designed for single-users, with high-resolution graphics facilities was the Xerox Alto developed at Xerox PARC in 1973, other early workstations include the Terak 8510/a, Three Rivers PERQ and the later Xerox Star. Meanwhile, DARPAs VLSI Project created several spinoff graphics products as well, notably the SGI3130 and it was not uncommon to differentiate the target market for the products, with Sun and Apollo considered to be network workstations, while the SGI machines were graphics workstations. As RISC microprocessors became available in the mid-1980s, these were adopted by many workstation vendors, workstations tended to be very expensive, typically several times the cost of a standard PC and sometimes costing as much as a new car. However, minicomputers sometimes cost as much as a house, additionally, workstations, given their more specialized nature, tend to have higher profit margins than commodity-driven PCs. Additionally, the companies that make the products tend to have very good repair/replacement plans, some low-cost workstations are still expensive by PC standards, but offer binary compatibility with higher-end workstations and servers made by the same vendor. This allows software development to take place on low-cost desktop machines, Graphics workstations often shipped with graphics accelerators
8.
Server (computing)
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In computing, a server is a computer program or a device that provides functionality for other programs or devices, called clients. This architecture is called the model, and a single overall computation is distributed across multiple processes or devices. Servers can provide various functionalities, often called services, such as sharing data or resources among multiple clients, a single server can serve multiple clients, and a single client can use multiple servers. A client process may run on the device or may connect over a network to a server on a different device. Typical servers are database servers, file servers, mail servers, print servers, web servers, game servers, designating a computer as server-class hardware implies that it is specialized for running servers on it. The use of the server in computing comes from queueing theory, where it dates to the mid 20th century, being notably used in Kendall. In earlier papers, such as the Erlang, more terms such as operators are used. In computing, server dates at least to RFC5, one of the earliest documents describing ARPANET, the use of serving also dates to early documents, such as RFC4, contrasting serving-host with using-host. The Jargon File defines server in the sense of a process performing service for requests, usually remote, with the 1981 version reading. A kind of DAEMON which performs a service for the requester, strictly speaking, the term server refers to a computer program or process. Through metonymy, it refers to a used to running one or several server programs. On a network, such a device is called a host, in addition to server, the words serve and service are frequently used, though servicer and servant are not. The word service may refer to either the form of functionality. Alternatively, it may refer to a program that turns a computer into a server. Originally used as servers serve users, in the sense of obey, today one says that servers serve data. For instance, web servers serve web pages to users or service their requests, the server is part of the client–server model, in this model, a server serves data for clients. The nature of communication between a client and server is request and response and this is in contrast with peer-to-peer model in which the relationship is on-demand reciprocation. In principle, any computerized process that can be used or called by another process is a server, thus any general purpose computer connected to a network can host servers
9.
ROMP
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The ROMP or Research OPD Micro Processor was a 10 MHz RISC microprocessor designed by IBM in the early 1980s. It is also known in circles as 032. OPD stands for Office Products Division, the division of IBM which originated the processor, the ROMP was manufactured on a 2 µm process with 45,000 transistors, saw first in silicon in 1981, and was originally developed to be used in office equipment and small computers. It was intended as a follow-on to a mid-1970s processor called the OPD Mini Processor, ROMP originally was shipped in the IBM RT/PC line, announced in 1986, and was later used in an IBM laser printer. For a time the IBM RT/PC was planned to be a personal computer, however, the software was targeted more towards engineering workstations. The original ROMP had a 24-bit Reduced Instruction Set Computer architecture developed by IBM and it was originally implemented in a 2 µm NMOS technology. It had sixteen 32-bit general purpose registers and used 32-bit addresses, the microprocessor was controlled by 118 simple two- and four-byte instructions. Internal processor organization enabled the CPU to execute most register-to-register instructions in a single cycle, an IBM-developed advanced memory management chip provided virtual memory address translation functions and memory control. The architectural work started in spring of 1977, as a spin-off of the T. J. Most of the changes were for cost reductions, such as adding 16-bit instructions for byte-efficiency. The first chips were ready in early 1981 and this delay was caused by overly ambitious software plans for the RT/PC and its operating system. This OS virtualized the hardware and could host multiple other operating systems and this technology, called virtualization, while commonplace in mainframe systems, only began to gain traction in smaller systems in the 21st century. The IBM RT/PC consequently fell behind competitors such as Sun Microsystems, the IBM RT PC ROMP processor and memory management unit architecture VLSI RISC Architecture and Organization, Stephen Bo Furber
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.
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
12.
IBM Personal System/2
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The Personal System/2 or PS/2 was IBMs third generation of personal computers. Released in 1987, it replaced the IBM PC, XT, AT. The PS/2 line was created by IBM in an attempt to control of the PC market by introducing an advanced yet proprietary architecture. IBMs considerable market presence plus the reliability of the PS/2 ensured that the systems would sell in large numbers. Also the evolving Wintel architecture was seeing a period of dramatic reductions in price, the OS/2 operating system was announced at the same time as the PS/2 line and was intended to be the primary operating system for models with Intel 286 or later processors. However, at the time of the first shipments, only PC DOS was available, OS/21.0 and Microsofts Windows 2.0 became available several months later. IBM also released AIX PS/2, a UNIX operating system for PS/2 models with Intel 386 or later processors, for years before IBM released the PS/2, rumors spread about IBMs plans for successors to its IBM PC, XT, and AT personal computers. Among the rumors that did not come true, The company would use proprietary, the company would release a version of its VM mainframe operating system for them. The company would design the new computers to make third-party communications products more difficult to design, IBMs PS/2 was designed to remain software compatible with their PC/AT/XT line of computers upon which the large PC clone market was built, but the hardware was quite different. CBIOS was so compatible that it even included Cassette BASIC, while IBM did not publish the BIOS source code, it did promise to publish BIOS entry points. With the IBM PS/2 line, Micro Channel Architecture was also introduced, MCA was conceptually similar to the channel architecture of the IBM System/360 mainframes. MCA was technically superior to ISA and allowed for higher speed communications within the system, MCA featured many advances not seen in other standards until several years later. Transfer speeds were on par with the much later PCI standard, MCA allowed one-to-one, card to card, and multi-card to processor simultaneous transaction management which is a feature of the PCI-X bus format. Bus mastering capability, bus arbitration, and a form of plug-and-play BIOS management of hardware were all benefits of MCA. (One book from the year 2000 writes, MCA used a version of what we know now as “Plug-N′-Play”, requiring a special setup disk for each machine. MCA never gained wide acceptance outside of the PS/2 line due to IBMs anti-clone practices and incompatibilities with ISA, IBM offered to sell an MCA license to anyone who could afford the royalty. However, royalties were required for every MCA-compatible machine sold and a payment for every IBM-compatible machine the particular maker had made in the past, there was nothing unique in IBM insisting on payment of royalties on the use of its patents applied to Micro Channel based machines. However, up until that time, some companies had failed to pay IBM for the use of its patents on the generation of Personal Computer
13.
IBM System/370
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The IBM System/370 was a model range of IBM mainframe computers announced on June 30,1970 as the successors to the System/360 family. A Dynamic Address Translation option was not announced until 1972, 128-bit floating point arithmetic on all models, the original System/370 line underwent several architectural improvements during its roughly 20-year lifetime. The first System/370 machines, the Model 155, the Model 165, and these changes included,13 new instructions, among which were MOVE LONG, COMPARE LOGICAL LONG, thereby permitting operations on up to 2^24-1 bytes, vs. They did not include support for virtual memory, in 1972, a very significant change was made when support for virtual memory was introduced with IBMs System/370 Advanced Function announcement. IBM had initially chosen to exclude virtual storage from the S/370 line, the S/370-145 had an associative memory used by the microcode for the DOS compatibility feature from its first shipments in June 1971, the same hardware was used by the microcode for DAT. The 145 microcode architecture simplified the addition of virtual memory, allowing this capability to be present in early 145s without the extensive modifications needed in other models. The Reference and Change bits of the Storage-protection Keys, however, were labeled on the rollers, existing S/370-145 customers were happy to learn that they did not have to purchase a hardware upgrade in order to run DOS/VS or OS/VS1. After installation, these models were known as the S/370-155-II and S/370-165-II, IBM wanted customers to upgrade their 155 and 165 systems to the widely sold S/370-158 and -168. This led to the original S/370-155 and S/370-165 models being described as boat anchors, later architectural changes primarily involved expansions in memory – both physical memory and virtual address space – to enable larger workloads and meet client demands for more storage. This was the trend as Moores Law eroded the unit cost of memory. As with all IBM mainframe development, preserving backward compatibility was paramount, in October 1981, the 3033 and 3081 processors added extended real addressing, which allowed 26-bit addressing for physical storage. This capability appeared later on other systems, such as the 4381 and 3090, the cross-memory services capability which facilitated movement of data between address spaces was actually available just prior to S/370-XA architecture on the 3031,3032 and 3033 processors. As described above, the S/370 product line underwent a major architectural change, the evolution of S/370 addressing was always complicated by the basic S/360 instruction set design, and its large installed code base, which relied on a 24-bit logical address. Most shops thus continued to run their 24-bit applications in a higher-performance 31-bit world and this evolutionary implementation had the characteristic of solving the most urgent problems first, relief for real memory addressing being needed sooner than virtual memory addressing. IBMs choice of 31-bit addressing for 370-XA involved various factors, the System/360 Model 67 had included a full 32-bit addressing mode, but this feature was not carried forward to the System/370 series, which began with only 24-bit addressing. When IBM later expanded the S/370 address space in S/370-XA, several reasons are cited for the choice of 31 bits, in particular, the standard subroutine calling convention marked the final parameter word by setting its high bit. Interaction between 32-bit addresses and two instructions that treated their arguments as signed numbers, input from key initial Model 67 sites, which had debated the alternatives during the initial system design period, and had recommended 31 bits. The following table summarizes the major S/370 series and models, the second column lists the principal architecture associated with each series
14.
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
15.
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
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User interface
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The user interface, in the industrial design field of human–computer interaction, is the space where interactions between humans and machines occur. Examples of this concept of user interfaces include the interactive aspects of computer operating systems, hand tools, heavy machinery operator controls. The design considerations applicable when creating user interfaces are related to or involve such disciplines as ergonomics and psychology. Generally, the goal of user interface design is to produce a user interface makes it easy, efficient. This generally means that the needs to provide minimal input to achieve the desired output. Other terms for user interface are man–machine interface and when the machine in question is a computer human–computer interface, the user interface or human–machine interface is the part of the machine that handles the human–machine interaction. Membrane switches, rubber keypads and touchscreens are examples of the part of the Human Machine Interface which we can see. In complex systems, the interface is typically computerized. The term human–computer interface refers to this kind of system, in the context of computing the term typically extends as well to the software dedicated to control the physical elements used for human-computer interaction. The engineering of the interfaces is enhanced by considering ergonomics. The corresponding disciplines are human factors engineering and usability engineering, which is part of systems engineering, tools used for incorporating human factors in the interface design are developed based on knowledge of computer science, such as computer graphics, operating systems, programming languages. Nowadays, we use the graphical user interface for human–machine interface on computers. There is a difference between a user interface and an interface or a human–machine interface. A human-machine interface is typically local to one machine or piece of equipment, an operator interface is the interface method by which multiple equipment that are linked by a host control system is accessed or controlled. The system may expose several user interfaces to serve different kinds of users, for example, a computerized library database might provide two user interfaces, one for library patrons and the other for library personnel. The user interface of a system, a vehicle or an industrial installation is sometimes referred to as the human–machine interface. HMI is a modification of the original term MMI, in practice, the abbreviation MMI is still frequently used although some may claim that MMI stands for something different now. Another abbreviation is HCI, but is commonly used for human–computer interaction
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KornShell
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KornShell is a Unix shell which was developed by David Korn at Bell Labs in the early 1980s and announced at USENIX on July 14,1983. The initial development was based on Bourne shell source code, other early contributors were Bell Labs developers Mike Veach and Pat Sullivan, who wrote the Emacs- and vi-style line editing modes code, respectively. KornShell is backward-compatible with the Bourne shell and includes features of the C shell. Job control was added to the Bourne Shell in 1989, a choice of three command line editing styles based on vi, Emacs, and XEmacs. Associative arrays and built-in floating point arithmetic operations, in 2000 the source code was released under a license particular to AT&T, but since the 93q release in early 2005 it has been licensed under the Eclipse Public License. KornShell is available as part of the AT&T Software Technology Open Source Software Collection, as KornShell was initially only available through a proprietary license from AT&T, a number of free and open source alternatives were created. These include pdksh, mksh, GNU bash, and zsh, ksh93 is still maintained by its author. This version also provides shell-level mappings for Motif widgets and it was intended as competitor to Tcl/Tk. The original KornShell, ksh88, became the default shell on AIX in version 4, unixWare 7 includes both ksh88 and ksh93. The default Korn shell is ksh93, which is supplied as /usr/bin/ksh, unixWare also includes dtksh when CDE is installed. There are several software products related to KornShell, dtksh – a fork of ksh93 included as part of CDE. tksh – a fork of ksh93 that provides access to the Tk widget toolkit, oksh – a Linux-based fork of OpenBSDs flavour of KornShell. It is used as the shell in DeLi Linux. Mksh – a free implementation of the KornShell language, forked from pdksh and it was originally developed for MirOS BSD and is licensed under permissive terms, specifically, the MirOS Licence. In addition to its usage on BSD, this variant has replaced pdksh on Debian, sKsh – an AmigaOS flavour that provides several Amiga-specific features, such as ARexx interoperability. KornShell is included in UWIN, a Unix compatibility package by David Korn, comparison of computer shells List of Unix utilities The test program Morris I. The new KornShell command and programming language, David G. Korn, Charles J. Northrup and Jeffery Korn The New KornShell—ksh93, Linux Journal, Issue 27, July 1996 Korn shell home page github for AT&T Software Technology, including ksh source code. Official KSH mailing lists, ast-developers and ast-users, ksh93 man page at the Wayback Machine ksh88 man page Public Domain Korn shell MirBSD Korn Shell mksh – MirOS BSD i386 General Commands Manual
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Common Desktop Environment
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The Common Desktop Environment is a desktop environment for Unix and OpenVMS, based on the Motif widget toolkit. It was part of the UNIX98 Workstation Product Standard, and was long the classic Unix desktop associated with commercial Unix workstations. After a long history as proprietary software, CDE was released as software on 6 August 2012, under the GNU Lesser General Public License. Since its release as free software, CDE has been ported to Linux, hewlett-Packard, IBM, SunSoft, and USL announced CDE in June 1993 as a joint development within the Common Open Software Environment initiative. Each development group contributed its own technology to CDE, HP contributed the primary environment for CDE, HP VUE was itself derived from the Motif Window Manager. IBM contributed its Common User Access model from OS/2s Workplace Shell, Sun contributed its ToolTalk application interaction framework and a port of its DeskSet productivity tools, including mail and calendar clients, from its OpenWindows environment. USL provided desktop manager components and scalable systems technologies from UNIX System V, after its release, HP endorsed CDE as the new standard desktop for Unix, and provided documentation and software for migrating HP VUE customizations to CDE. OSF became part of the newly formed Open Group in 1996, in February 1997, the Open Group released their last major version of CDE, version 2.1. Red Hat Linux was the only Linux distribution to which proprietary CDE was ported, in 1997, Red Hat began offering a version of CDE licensed from TriTeal Corporation. In 1998, Xi Graphics, a company specializing in the X Windowing System, offered a version of CDE bundled with Red Hat Linux and these were phased out, and Red Hat moved to the GNOME desktop. In 2001, Sun Microsystems announced that they would phase out CDE as the standard Solaris desktop environment in favor of GNOME, Solaris 10, released in early 2005, includes both CDE and the GNOME-based Java Desktop System. The Solaris 11 release in November 2011 only contains GNOME as a desktop, though some CDE libraries, such as Motif and Tooltalk. The OpenSolaris open source project did not include CDE, and had no intent to make Solaris CDE available as open source, IBM AIX Digital UNIX HP-UX, from version 10.10, released in 1996. IRIX, for a short time CDE was an alternative to IID, OpenVMS Solaris, available starting with 2.3, standard in 2.6 to 10. Tru64 UNIX UnixWare UXP/DS Red Hat Linux, Two versions ported by Triteal and Xi Graphics From its launch until 2012, Motif, the toolkit on which CDE is built, was released by The Open Group in 2000 as Open Motif, under a revenue sharing license. That license did not meet either the source or free software definitions. The Open Group had wished to make Motif open source, in 2006, a petition was created asking The Open Group to release the source code for CDE and Motif under a free license. On August 6,2012, CDE was open-sourced under the LGPL free software license, the CDE source code was then released to SourceForge
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KDE Plasma Workspaces
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KDE is an international free software community that develops Free and Libre software. Well-known products include the Plasma Desktop, KDE Frameworks and a range of applications designed to run on modern Unix-like. It further provides tools and documentation for developers that enables them to write software and this supporting role makes KDE a central development hub and home for many popular applications and projects like Calligra Suite, Krita or digiKam. The Plasma Desktop, being one of the most recognized projects of KDE, is the desktop environment on many Linux distributions, such as openSUSE, Mageia, Chakra, Kubuntu. It was also the default desktop environment on PC-BSD, but was replaced with Lumina. The work of the KDE community can be measured in the following figures, more than 1800 contributors participate in developing KDE software. About 20 new developers contribute their first code each month, KDE Software consists of over 6 million lines of code. KDE Software is translated in over 108 languages, KDE Software is available on more than 114 official FTP mirrors in over 34 countries. A read-only mirror of all repositories can be found on Github, K Desktop Environment was founded in 1996 by Matthias Ettrich, who was then a student at the Eberhard Karls University of Tübingen. At the time, he was troubled by certain aspects of the Unix desktop, among his concerns was that none of the applications looked, felt, or worked alike. He proposed the creation of not merely a set of applications but a desktop environment in which users could expect things to look, feel, and work consistently. He also wanted to make this easy to use, one of his complaints about desktop applications of the time was that it is too complicated for end user. His initial Usenet post spurred a lot of interest, and the KDE project was born, the name KDE was intended as a wordplay on the existing Common Desktop Environment, available for Unix systems. CDE is an X11-based user environment jointly developed by HP, IBM and it was supposed to be an intuitively easy-to-use desktop computer environment. The K was originally suggested to stand for Kool, but it was decided that the K should stand for nothing in particular. Therefore, the KDE initialism expanded to K Desktop Environment before it was dropped altogether in favor of KDE = Community due to the rebranding effort. The rebranding focused on de-emphasizing the desktop environment as just another product, what would have been previously known as KDE4 was split into three products, Plasma Workspaces, KDE Applications, and KDE Platform – bundled as KDE Software Compilation 4. As of today the name KDE no longer stands for K Desktop Environment, the financial and legal matters of KDE are handled by KDE e. V
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GNOME
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GNOME is a desktop environment composed of free and open-source software that runs on Linux and most BSD derivatives. GNOME was originally an acronym for GNU Network Object Model Environment, GNOME is developed by The GNOME Project, which is composed of both volunteers and paid contributors, the largest corporate contributor being Red Hat. GNOME is part of the GNU Project, since GNOME2, productivity has been a key focus for GNOME. To this end, the GNOME Human Interface Guidelines were created, all GNOME programs share a coherent style of graphical user interface but are not limited to the employment of the same GUI widgets. Rather, the design of the GNOME GUI is guided by concepts described in the GNOME HIG, following the HIG, developers can create high-quality, consistent, and usable GUI programs, as it addresses everything from GUI design to recommended pixel-based layout of widgets. During the GNOME2 rewrite, many settings deemed of value to the majority of users were removed. Or even configurable to be the union of all applications that anyones ever seen on any historical platform and it turns out that preferences have a cost. Of course, some also have important benefits – and can be crucial interface features. But each one has a price, and you have to consider its value. Many users and developers dont understand this, and end up with a lot of cost, GNOME aims to make and keep the desktop environment physically and cognitively ergonomic for people with disabilities. The GNOME HIG tries to take this account as far as possible. Particular utilities are registered with ATK using Assistive Technology Service Provider Interface, several assistive technology providers, including Orca screen reader and Dasher input method, were developed specifically for use with GNOME. GNOME Shell is the user interface of the GNOME desktop environment. It features a top bar holding an Activities button, a menu, a clock. The status menu holds various system status indicators, shortcuts to system settings, and session actions including logging out, switching users, locking the screen, clicking on the Activities button, moving the mouse to the top-left hot corner or pressing the Super key brings up the Overview. The Overview gives users an overview of current activities and provides a way to switch between windows and workspaces and to launch applications, the Dash on the left houses shortcuts to favorite applications and open windows and an application picker button to show a list of all installed applications. A search bar appears at the top and a workspace list for switching between workspaces is on the right, notifications appear from the bottom of the screen. Beginning with GNOME3.8, GNOME provides a Classic Mode for those who prefer a traditional desktop experience, GNOME3.24 will extend Wayland compatibility to NVidia drivers
21.
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
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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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Reduced instruction set computer
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A computer based on this strategy is a reduced instruction set computer, also called RISC. The opposing architecture is called complex instruction set computing, although a number of systems from the 1960s and 70s have been identified as being forerunners of RISC, the modern version of the design dates to the 1980s. In particular, two projects at Stanford University and University of California, Berkeley are most associated with the popularization of this concept. Stanfords design would go on to be commercialized as the successful MIPS architecture, while Berkeleys RISC gave its name to the entire concept, another success from this era were IBMs efforts that eventually led to the Power Architecture. RISC families include DEC Alpha, AMD Am29000, ARC, ARM, Atmel AVR, Blackfin, Intel i860 and i960, MIPS, Motorola 88000, PA-RISC, Power, RISC-V, SuperH, and SPARC. In the 21st century, the use of ARM architecture processors in smart phones and tablet computers such as the iPad, a number of systems, going back to the 1960s, have been credited as the first RISC architecture, partly based on their use of load/store approach. The term RISC was coined by David Patterson of the Berkeley RISC project, michael J. Flynn views the first RISC system as the IBM801 design which began in 1975 by John Cocke, and completed in 1980. The 801 was eventually produced in a form as the ROMP in 1981. As the name implies, this CPU was designed for tasks, and was also used in the IBM RT-PC in 1986. But the 801 inspired several research projects, including new ones at IBM that would lead to the IBM POWER instruction set architecture. The most public RISC designs, however, were the results of university research programs run with funding from the DARPA VLSI Program, the VLSI Program, practically unknown today, led to a huge number of advances in chip design, fabrication, and even computer graphics. The Berkeley RISC project started in 1980 under the direction of David Patterson, Berkeley RISC was based on gaining performance through the use of pipelining and an aggressive use of a technique known as register windowing. In a traditional CPU, one has a number of registers. In a CPU with register windows, there are a number of registers, e. g.128. The Berkeley RISC project delivered the RISC-I processor in 1982, consisting of only 44,420 transistors RISC-I had only 32 instructions, and yet completely outperformed any other single-chip design. They followed this up with the 40,760 transistor,39 instruction RISC-II in 1983, which ran over three times as fast as RISC-I. The MIPS architecture grew out of a course by John L. Hennessy at Stanford University in 1981, resulted in a functioning system in 1983. The MIPS approach emphasized an aggressive clock cycle and the use of the pipeline, the MIPS system was followed by the MIPS-X and in 1984 Hennessy and his colleagues formed MIPS Computer Systems
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RS/6000
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RISC System/6000, or RS/6000 for short, is a family of RISC-based UNIX servers, workstations and supercomputers made by IBM in the 1990s. The RS/6000 family replaced the IBM RT computer platform in February 1990 and was the first computer line to see the use of IBMs POWER, RS/6000 was renamed eServer pSeries in October 2000. The first generations of RS/6000 systems used the Micro Channel bus technology, some later models used the standardized PReP and CHRP platforms, co-developed with Apple and Motorola, with Open Firmware. Linux is widely used on CHRP based RS/6000s, but support was added after the RS/6000 name was changed to eServer pSeries in 2000, RS/6000 types of computers are the POWERserver servers, POWERstation workstations and Scalable POWERparallel supercomputer platform. While most machines were desktops, desksides, or rack mounted, there was a laptop model too, some models were marketed under the RS/6000 POWERstation and POWERserver names. The Model N40 was PowerPC-based notebook developed and manufactured by Tadpole Technology for IBM and it became available on 25 March 1994, priced at US$12,000. The internal batteries could power the system for 45 minutes only and these workstations were marketed under the PowerStation name. This type was for Xstations, IBMs line of X terminal, the 380,390, and 39H servers correspond to the 3AT, 3BT, and 3CT workstations. Many RS/6000 and subsequent pSeries machines came with a service processor, the service processor could call a phone number in case of serious failure with the machine. Late in the RS/6000 cycle, the processor was converged with the one used on the AS/400 machines. IBM POWER microprocessors IBM AIX IBM Scalable POWERparallel IBM pSeries IBM System p General 27 years of IBM RISC IBM Archives, A Brief History of RISC, the IBM RS/6000 and the IBM eServer pSeries
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IBM POWER microprocessors
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IBM has a series of high performance microprocessors called POWER followed by a number designating generation, i. e. POWER1, POWER2, POWER3 and so forth up to the latest POWER9. These processors have used by IBM in their RS/6000, AS/400, pSeries, iSeries, System p, System i. They have also used in data storage devices by IBM and by other server manufacturers like Bull. The POWERn family of processors were developed in the late 1980s and are still in active development nearly 30 years later, in the beginning, they utilized the POWER instruction set architecture, but that evolved into PowerPC in later generations and then to Power Architecture. Today, only the naming scheme remains the same, modern POWER processors do not use the POWER ISA, in 1974 IBM started a project to build a telephone switching computer with, for the time, immense computational power. When the telephone switch project was cancelled IBM kept the design for the general purpose processor, many changes were made to the 801 design to allow for multiple execution units and the Cheetah processor had separate branch prediction, fixed-point, and floating-point execution units. By 1984 CMOS was chosen since it allowed an increase in the level of integration while improving transistor-logic performance. This was to become the first POWER processors using the first POWER ISA, in February 1990, the first computers from IBM to incorporate the POWER ISA were called the RISC System/6000 or RS/6000. These RS/6000 computers were divided into two classes, workstations and servers, and hence introduced as the POWERstation and POWERserver, the RS/6000 CPU had 2 configurations, called the RIOS-1 and RIOS.9. The POWER1 is the first microprocessor that used register renaming and out-of-order execution, a simplified and less powerful version of the 10 chip RIOS-1 was made in 1992 was developed for lower-end RS/6000s. It used only one chip and was called RISC Single Chip or RSC, RIOS-1 – the original 10-chip version RIOS. The POWER2 was a design, but IBM also made a single chip design of it. At the time of its introduction in 1996, the P2SC was the largest processor with the highest transistor count in the industry and was a leader in floating point operations. IBM joined the discussion and the three founded the AIM alliance to build the PowerPC ISA, heavily based on the POWER ISA, but with additions from both Apple and Motorola. It was to be a complete 32/64 bit RISC architecture, with a promise to range from low end embedded microcontrollers to the very high end supercomputer and server applications. After two years of development, the resulting PowerPC ISA was introduced in 1993 and it also added a 64-bit version of the ISA and support for SMP. The POWER3 began its life as PowerPC630, a successor of the commercially unsuccessful PowerPC620 and it used a combination of the POWER2 ISA and the 32/64-bit PowerPC ISA set with support for SMP and single-chip implementation. It was used to great extent in IBMs RS/6000 computers, while the second generation version, the POWER3 was the last processor to use a POWER instruction set, all subsequent models used some version of the PowerPC instruction set
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IBM System i
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The IBM System i is IBMs previous generation of midrange computer systems for IBM i users, and was subsequently replaced by the IBM Power Systems in April 2008. The platform was first introduced as the AS/400 on June 21,1988, as part of IBMs Systems branding initiative in 2006, it was again renamed to System i. The codename of the AS/400 project was Silver Lake, named for the lake in downtown Rochester, Minnesota, in April 2008, IBM announced its integration with the System p platform. The unified product line is called IBM Power Systems and features support for the IBM i, AIX, the predecessor to AS/400, IBM System/38, was first made available in August 1979 and was marketed as a minicomputer for general business and departmental use. It was sold alongside other product lines, each with a different architecture, realizing the importance of compatibility with the thousands of programs written in legacy code, IBM launched the AS/400 midrange computer line in 1988. Great effort was made during development of the AS/400 to enable programs written for the System/34, in 2000, in accordance with IBMs eServer initiative, the AS/400 series was rebranded as the eServer iSeries. In 2006, it was rebranded as the IBM System i. In 2008, almost 20 years after being introduced, the System i, the AS/400 operating system was originally named OS/400. The operating system has undergone name changes along with the rebranding of IBMs server lineup, the operating system was rebranded as i5/OS to correspond with the introduction of POWER5 processors and the rebranding of the hardware to eServer iSeries. For the 6.1 release, the system was again renamed to IBM i. Features include a RDBMS, an interface, support for multiple users, block-oriented terminal support. Unlike the everything is a feature of Unix and its derivatives. IBM i offers Unix-like file directories using the Integrated File System, Java compatibility is implemented through a native port of the Java virtual machine. Like IBMs mainframe operating systems, IBM i uses EBCDIC as the inherent encoding, OS/400 Version 4, Release 4 introduced LPARs allowing multiple virtual systems to run on a single hardware footprint. The IBM System i platform extended the System/38 architecture of a system with an integrated DB2 relational database. Equally important are the machine and single-level storage concepts which established the platform as an advanced business computer. TIMI is an instruction set independent of the underlying machine instruction set of the CPU. User-mode programs contain both TIMI instructions and the instructions of the CPU, thus ensuring hardware independence
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Personal computer
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A personal computer is a multi-purpose electronic computer whose size, capabilities, and price make it feasible for individual use. PCs are intended to be operated directly by a end-user, rather than by an expert or technician. In the 2010s, PCs are typically connected to the Internet, allowing access to the World Wide Web, personal computers may be connected to a local area network, either by a cable or a wireless connection. In the 2010s, a PC may be, a multi-component desktop computer, designed for use in a location a laptop computer, designed for easy portability or a tablet computer. In the 2010s, PCs run using a system, such as Microsoft Windows, Linux. The very earliest microcomputers, equipped with a front panel, required hand-loading of a program to load programs from external storage. Before long, automatic booting from permanent read-only memory became universal, in the 2010s, users have access to a wide range of commercial software, free software and free and open-source software, which are provided in ready-to-run or ready-to-compile form. Since the early 1990s, Microsoft operating systems and Intel hardware have dominated much of the computer market, first with MS-DOS. Alternatives to Microsofts Windows operating systems occupy a minority share of the industry and these include Apples OS X and free open-source Unix-like operating systems such as Linux and Berkeley Software Distribution. Advanced Micro Devices provides the alternative to Intels processors. PC is an initialism for personal computer, some PCs, including the OLPC XOs, are equipped with x86 or x64 processors but not designed to run Microsoft Windows. PC is used in contrast with Mac, an Apple Macintosh computer and this sense of the word is used in the Get a Mac advertisement campaign that ran between 2006 and 2009, as well as its rival, Im a PC campaign, that appeared in 2008. Since Apples transition to Intel processors starting 2005, all Macintosh computers are now PCs, the “brain” may one day come down to our level and help with our income-tax and book-keeping calculations. But this is speculation and there is no sign of it so far, in the history of computing there were many examples of computers designed to be used by one person, as opposed to terminals connected to mainframe computers. Using the narrow definition of operated by one person, the first personal computer was the ENIAC which became operational in 1946 and it did not meet further definitions of affordable or easy to use. An example of an early single-user computer was the LGP-30, created in 1956 by Stan Frankel and used for science and it came with a retail price of $47, 000—equivalent to about $414,000 today. Introduced at the 1965 New York Worlds Fair, the Programma 101 was a programmable calculator described in advertisements as a desktop computer. It was manufactured by the Italian company Olivetti and invented by the Italian engineer Pier Giorgio Perotto, the Soviet MIR series of computers was developed from 1965 to 1969 in a group headed by Victor Glushkov
28.
Apple Network Server
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The Apple Network Server was a short-lived line of PowerPC-based server computers manufactured by Apple Computer from February 1996 to April 1997, when it was discontinued due to poor sales. They are not a part of the Apple Macintosh line of computers, they were designed to run IBMs AIX operating system and this makes them the last non-Macintosh desktop computers made by Apple to date. The 500/132, 700/150, and 700/200 sold in the U. S. market for $11,000, $15,000 and $19,000, Apple did not have comparable server hardware in their product lineup again until the introduction of the Xserve in 2002. The Apple Network Servers hardware was supposed to be based on a new board design specific to the product. During the development of the hardware, Apple abandoned the original design for unconfirmed reasons. In order to forward and ship the product, Apple made modifications to the Power Macintosh 9500 logic board and ROM. Whether related to the change or by coincidence, Apple also abandoned its NetWare on PowerPC development at this time. The general logic board layout seems to suggest a relationship with PowerPC-based RS/6000 systems by IBM. On the other hand, many logic board components, especially the Open Firmware boot ROM, are similar to the Tsunami board used in the Power Macintosh 9500 and some Macintosh clones. Starting at the top level bus and working downward in the bus hierarchy, the CPU, as mentioned, is a PowerPC604 or 604e. The CPU bus-to-PCI bus bridges are Bandit controllers, both the ANS and the PM9500 have two Bandit controllers and two separate PCI busses. All devices at the CPU bus level are identical between the ANS and PM9500, on both systems the CPU Bus Clock is supplied by the removable CPU card. However, on the ANS the clock buffer which splits the System Clock for all the CPU Bus Devices is on the logic board, the memory data lane controllers are different on the ANS from the ones on the PM9500, presumably because of added support for parity memory. The ANS memory data lane controllers are 343S1161 instead of 343S1141 as on the PM9500, however, the memory structure is the same with two banks of DIMM slots and support for memory interleaving when corresponding slots in different banks contain identical memory DIMMs. The ANS does have eight memory DIMM slots instead of the PM9500s twelve, on the PCI bus, as mentioned above, the ANS uses the Bandit PCI bridge, just as the PM9500 does. The PCI bus arbiters are also identical, the bus arbiters receive the PCI Bus Request signals and issue the Bus Grant Signals to the PCI slots and to the PCI bridge chips. The interrupt manager and logic board IO controller is also the same, Grand Central is a device on the PCI bus. At the PCI bus, ANS parts ways with the PM9500 in a few ways, the ANS has two 53C825A SCSI chips with support for Fast & Wide SCSI operations, which are not present in the PM9500
29.
UNIX System V
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UNIX System V is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983, four major versions of System V were released, numbered 1,2,3, and 4. It was the source of common commercial Unix features. System V is sometimes abbreviated to SysV, as of 2012, the Unix market is divided between three System V variants, IBMs AIX, Hewlett-Packards HP-UX and Oracles Solaris. System V was the successor to 1982s UNIX System III, while AT&T sold their own hardware that ran System V, most customers instead ran a version from a reseller, based on AT&Ts reference implementation. A standards document called the System V Interface Definition outlined the default features, in the 1980s and early-1990s, System V was considered one of the two major versions of UNIX, the other being the Berkeley Software Distribution. Historically, BSD was also commonly called BSD Unix or Berkeley Unix, the dispute had several levels, some technical and some cultural. The divide was roughly between longhairs and shorthairs, programmers and technical people tended to line up with Berkeley and BSD, more business-oriented types with AT&T and System V. While HP, IBM and others chose System V as the basis for their Unix offerings, other such as Sun Microsystems. Throughout its development, though, System V was infused with features from BSD, since the early 1990s, due to standardization efforts such as POSIX and the commercial success of Linux, the division between System V and BSD has become less important. System V, known inside Bell Labs as Unix 5.0, there was never an external release of Unix 4.0, which would have been System IV. This first release of System V was developed by AT&Ts UNIX Support Group, System V also included features such as the vi editor and curses from 4.1 BSD, developed at the University of California, Berkeley, it also improved performance by adding buffer and inode caches. It also added support for communication using messages, semaphores. SVR1 ran on DEC PDP-11 and VAX minicomputers, System V Release 2 was released in April,1984. It added shell functions and the SVID, new kernel features included record and file locking, demand paging, and copy on write. The concept of the base was formalized, and the DEC VAX-11/780 was chosen for this release. The porting base is the original version of a release. Educational source licenses for SVR2 were offered by AT&T for US$800 for the first CPU, a commercial source license was offered for $43,000, with three months of support, and a $16,000 price per additional CPU
30.
Berkeley Software Distribution
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Berkeley Software Distribution is a Unix operating system derivative developed and distributed by the Computer Systems Research Group of the University of California, Berkeley, from 1977 to 1995. Today the term BSD is often used non-specifically to refer to any of the BSD descendants which together form a branch of the family of Unix-like operating systems, operating systems derived from the original BSD code remain actively developed and widely used. Historically, BSD has been considered a branch of Unix, Berkeley Unix, because it shared the initial codebase, in the 1980s, BSD was widely adopted by vendors of workstation-class systems in the form of proprietary Unix variants such as DEC ULTRIX and Sun Microsystems SunOS. This can be attributed to the ease with which it could be licensed, FreeBSD, OpenBSD, NetBSD, Darwin, and PC-BSD. The earliest distributions of Unix from Bell Labs in the 1970s included the source code to the system, allowing researchers at universities to modify. A larger PDP-11/70 was installed at Berkeley the following year, using money from the Ingres database project, also in 1975, Ken Thompson took a sabbatical from Bell Labs and came to Berkeley as a visiting professor. He helped to install Version 6 Unix and started working on a Pascal implementation for the system, graduate students Chuck Haley and Bill Joy improved Thompsons Pascal and implemented an improved text editor, ex. Other universities became interested in the software at Berkeley, and so in 1977 Joy started compiling the first Berkeley Software Distribution, 1BSD was an add-on to Version 6 Unix rather than a complete operating system in its own right. Some thirty copies were sent out, some 75 copies of 2BSD were sent out by Bill Joy. 2. 9BSD from 1983 included code from 4. 1cBSD, the most recent release,2. 11BSD, was first issued in 1992. As of 2008, maintenance updates from volunteers are still continuing, a VAX computer was installed at Berkeley in 1978, but the port of Unix to the VAX architecture, UNIX/32V, did not take advantage of the VAXs virtual memory capabilities. 3BSD was also alternatively called Virtual VAX/UNIX or VMUNIX, and BSD kernel images were normally called /vmunix until 4. 4BSD, 4BSD offered a number of enhancements over 3BSD, notably job control in the previously released csh, delivermail, reliable signals, and the Curses programming library. In a 1985 review of BSD releases, John Quarterman et al, many installations inside the Bell System ran 4. 1BSD. 4. 1BSD was a response to criticisms of BSDs performance relative to the dominant VAX operating system, the 4. 1BSD kernel was systematically tuned up by Bill Joy until it could perform as well as VMS on several benchmarks. Back at Bell Labs,4. 1cBSD became the basis of the 8th Edition of Research Unix, to guide the design of 4. The committee met from April 1981 to June 1983, apart from the Fast File System, several features from outside contributors were accepted, including disk quotas and job control. Sun Microsystems provided testing on its Motorola 68000 machines prior to release, the official 4. 2BSD release came in August 1983. On a lighter note, it marked the debut of BSDs daemon mascot in a drawing by John Lasseter that appeared on the cover of the printed manuals distributed by USENIX
31.
MacOS
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Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows. Launched in 2001 as Mac OS X, the series is the latest in the family of Macintosh operating systems, Mac OS X succeeded classic Mac OS, which was introduced in 1984, and the final release of which was Mac OS9 in 1999. An initial, early version of the system, Mac OS X Server 1.0, was released in 1999, the first desktop version, Mac OS X10.0, followed in March 2001. In 2012, Apple rebranded Mac OS X to OS X. Releases were code named after big cats from the release up until OS X10.8 Mountain Lion. Beginning in 2013 with OS X10.9 Mavericks, releases have been named after landmarks in California, in 2016, Apple rebranded OS X to macOS, adopting the nomenclature that it uses for their other operating systems, iOS, watchOS, and tvOS. The latest version of macOS is macOS10.12 Sierra, macOS is based on technologies developed at NeXT between 1985 and 1997, when Apple acquired the company. The X in Mac OS X and OS X is pronounced ten, macOS shares its Unix-based core, named Darwin, and many of its frameworks with iOS, tvOS and watchOS. A heavily modified version of Mac OS X10.4 Tiger was used for the first-generation Apple TV, Apple also used to have a separate line of releases of Mac OS X designed for servers. Beginning with Mac OS X10.7 Lion, the functions were made available as a separate package on the Mac App Store. Releases of Mac OS X from 1999 to 2005 can run only on the PowerPC-based Macs from the time period, Mac OS X10.5 Leopard was released as a Universal binary, meaning the installer disc supported both Intel and PowerPC processors. In 2009, Apple released Mac OS X10.6 Snow Leopard, in 2011, Apple released Mac OS X10.7 Lion, which no longer supported 32-bit Intel processors and also did not include Rosetta. All versions of the system released since then run exclusively on 64-bit Intel CPUs, the heritage of what would become macOS had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, and then launched in 1989 and its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. This led Apple to purchase NeXT in 1996, allowing NeXTSTEP, then called OPENSTEP, previous Macintosh operating systems were named using Arabic numerals, e. g. Mac OS8 and Mac OS9. The letter X in Mac OS Xs name refers to the number 10 and it is therefore correctly pronounced ten /ˈtɛn/ in this context. However, a common mispronunciation is X /ˈɛks/, consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API, the consumer version of Mac OS X was launched in 2001 with Mac OS X10.0. Reviews were variable, with praise for its sophisticated, glossy Aqua interface
32.
Solaris (operating system)
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Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993, Oracle Solaris, so named as of 2010, has been owned by Oracle Corporation since the Sun acquisition by Oracle in January 2010. Solaris is known for its scalability, especially on SPARC systems, Solaris supports SPARC-based and x86-based workstations and servers from Oracle and other vendors, with efforts underway to port to additional platforms. Solaris is registered as compliant with the Single Unix Specification, historically, Solaris was developed as proprietary software. In June 2005, Sun Microsystems released most of the codebase under the CDDL license, with OpenSolaris, Sun wanted to build a developer and user community around the software. After the acquisition of Sun Microsystems in January 2010, Oracle decided to discontinue the OpenSolaris distribution, in August 2010, Oracle discontinued providing public updates to the source code of the Solaris kernel, effectively turning Solaris 11 back into a closed source proprietary operating system. Following that, in 2011 the Solaris 11 kernel source code leaked to BitTorrent, however, through the Oracle Technology Network, industry partners can still gain access to the in-development Solaris source code. Source code for the source components of Solaris 11 is available for download from Oracle. In 1987, AT&T Corporation and Sun announced that they were collaborating on a project to merge the most popular Unix variants on the market at that time, BSD, System V and this became Unix System V Release 4. On September 4,1991, Sun announced that it would replace its existing BSD-derived Unix, SunOS4 and this was identified internally as SunOS5, but a new marketing name was introduced at the same time, Solaris 2. The justification for this new overbrand was that it encompassed not only SunOS, but also the OpenWindows graphical user interface and Open Network Computing functionality. Although SunOS4.1. x micro releases were retroactively named Solaris 1 by Sun, for releases based on SunOS5, the SunOS minor version is included in the Solaris release number. For example, Solaris 2.4 incorporates SunOS5.4. After Solaris 2.6, the 2. was dropped from the name, so Solaris 7 incorporates SunOS5.7. Although SunSoft stated in its initial Solaris 2 press release their intent to support both SPARC and x86 systems, the first two Solaris 2 releases,2.0 and 2.1, were SPARC-only. An x86 version of Solaris 2.1 was released in June 1993, about 6 months after the SPARC version, as a desktop and it included the Wabi emulator to support Windows applications. At the time, Sun also offered the Interactive Unix system that it had acquired from Interactive Systems Corporation, in 1994, Sun released Solaris 2.4, supporting both SPARC and x86 systems from a unified source code base. Solaris uses a code base for the platforms it supports, SPARC
33.
HP-UX
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HP-UX is Hewlett Packard Enterprises proprietary implementation of the Unix operating system, based on UNIX System V and first released in 1984. Recent versions support the HP9000 series of systems, based on the PA-RISC instruction set architecture. HP-UX was the first Unix to offer access control lists for file access permissions as an alternative to the standard Unix permissions system, HP-UX was also among the first Unix systems to include a built-in logical volume manager. HP has had a partnership with Veritas Software, and uses VxFS as the primary file system. It is one of six operating systems that have versions certified to The Open Groups UNIX03 standard. HP-UX 11i offers a common root disk for its file system. HP Serviceguard is the solution for HP-UX. HPVM supports guests running on HP-UX 11i v3 hosts – guests can run Linux, Windows, HP supports online VM guest migration, where encryption can secure the guest contents during migration. A directory containing such files had its suid bit set and was hidden from both ordinary and root processes under normal use. Such a scheme was sometimes exploited by intruders to hide malicious programs or data, cDFs and the CDF filesystem were dropped with release 10.0. HP-UX operating systems supports a variety of PA-RISC systems, the 11.0 added support for Integrity-based servers for the transition from PA-RISC to Itanium. HP-UX 11i v1.5 is the first version that supported Itanium, on the introduction of HP-UX 11i v2 the operating system supported both of these architectures. HP-UX 11i supports HP Integrity Servers of HP BL server blade family and these servers use the Intel Itanium architecture. HP-UX 11i v2 and 11i v3 support HPs CX series servers, CX stands for carrier grade and is used mainly for telco industry with -48V DC support and is NEBS certified. Both of these systems contain Itanium Mad6M processors and are discontinued, HP-UX supports HPs RX series of servers. Prior to the release of HP-UX version 11.11, HP used a decimal version numbering scheme with the first number giving the major release, with 11.11, HP made a marketing decision to name their releases 11i followed by a v for the version. The i was intended to indicate the OS is Internet-enabled,1.0 First release for HP9000 Series 500. HP-UX for Series 500 was substantially different that HP-UX for any other HP machines, Support for the HP Integral PC
34.
IBM Power Systems
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Power Systems is IBMs Power Architecture-based server line. Before the Power Systems line was announced on April 2,2008 and they merged to use essentially the same hardware platform in 2001/2002 with the introduction of the POWER4 processor. After that, there was little difference between both the p and the i hardware, the differences were in the software and services offerings. With the introduction of the POWER5 processor in 2004, even the product numbering was synchronized, the System i5570 was virtually identical to the System p5570
35.
IBM i
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IBM i is an operating system that runs on IBM Power Systems and on IBM PureSystems. It is one of the operating systems supported on IBM Power Systems alongside AIX and Linux as well as on IBM PureSystems alongside AIX, Linux, IBM i programs, like System/38 programs before them, contain both processor-independent virtual binary code and processor-dependent executable binary code. Notably, when migrating from a processor, the only effect that most organizations notice is that the program runs somewhat longer when it runs for the first time on the new computer. Migration consists of taking a backup from the old computer, IBM designed IBM i as a turnkey operating system, requiring little or no on-site attention from IT staff during normal operation. For example, IBM i has a built-in DB2 database which does not require separate installation, disks are multiply redundant, and can be replaced on line without interrupting work. Hardware and software maintenance tasks are integrated, system administration has been wizard-driven for years, even before that term was defined. This automatic self-care policy goes so far as to automatically schedule all common system maintenance, detect many failures and even order spare parts, organizations using i sometimes have sticker shock when confronting the cost of system maintenance on other systems. Another peculiar feature is that this system was one of the earliest to be object-based, unlike traditional OSes like UNIX and Windows NT there are no files, only objects of different types. It implemented one of the systems for persistent objects. Further, the objects persist in very large, flat virtual memory, called a single-level store. IBM Systems Director Navigator for i now can be used to manage target servers running IBM i 5.4,6.1 or 7.1 from a single browser environment with the IBM i 7.1. In 1999, IBM introduced logical partitioning with i5/OS to support multiple virtual systems on a single hardware footprint, in 2011, IBM and Zend Technologies announced Zend DBi as replacement for the MySQL on IBM i support with a first General availability release in 2012. In 2013, IBM and PowerRuby Inc. announced PowerRuby as a commercially supported port of the Ruby programming language, PowerRuby will be offered as a free download to be installed on customer machines. In 2014, IBM ported Node. js to IBM i, the latest version of IBM i is 7.3, announced on April 12,2016 and released on April 15,2016. With 7.1, IBM started delivering new updates to the system via Technology Refreshes. Version 7.2 was released in May 2014, version 7.3 was released in April 2016. Auxiliary storage pool Multics for an earlier system which provided persistent objects User groups have played a major part in the evolution of the IBM i. The largest such group is COMMON, the Large User Group, whos membership consists of major corporations, is a major influence for current and future development of IBM i
36.
Linux
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Linux is a Unix-like computer operating system assembled under the model of free and open-source software development and distribution. The defining component of Linux is the Linux kernel, an operating system kernel first released on September 17,1991 by Linus Torvalds, the Free Software Foundation uses the name GNU/Linux to describe the operating system, which has led to some controversy. Linux was originally developed for computers based on the Intel x86 architecture. Because of the dominance of Android on smartphones, Linux has the largest installed base of all operating systems. Linux is also the operating system on servers and other big iron systems such as mainframe computers. It is used by around 2. 3% of desktop computers, the Chromebook, which runs on Chrome OS, dominates the US K–12 education market and represents nearly 20% of the sub-$300 notebook sales in the US. Linux also runs on embedded systems – devices whose operating system is built into the firmware and is highly tailored to the system. This includes TiVo and similar DVR devices, network routers, facility automation controls, televisions, many smartphones and tablet computers run Android and other Linux derivatives. The development of Linux is one of the most prominent examples of free, the underlying source code may be used, modified and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License. Typically, Linux is packaged in a known as a Linux distribution for both desktop and server use. Distributions intended to run on servers may omit all graphical environments from the standard install, because Linux is freely redistributable, anyone may create a distribution for any intended use. The Unix operating system was conceived and implemented in 1969 at AT&Ts Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, first released in 1971, Unix was written entirely in assembly language, as was common practice at the time. Later, in a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie, the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, as a result, Unix grew quickly and became widely adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs, freed of the legal obligation requiring free licensing, the GNU Project, started in 1983 by Richard Stallman, has the goal of creating a complete Unix-compatible software system composed entirely of free software. Later, in 1985, Stallman started the Free Software Foundation, by the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers, daemons, and the kernel were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, although not released until 1992 due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has also stated that if 386BSD had been available at the time, although the complete source code of MINIX was freely available, the licensing terms prevented it from being free software until the licensing changed in April 2000
37.
Reliability engineering
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Reliability engineering is engineering that emphasizes dependability in the lifecycle management of a product. Dependability, or reliability, describes the ability of a system or component to function under stated conditions for a period of time. Reliability may also describe the ability to function at a moment or interval of time. Reliability engineering represents a sub-discipline within systems engineering, Testability, Maintainability and maintenance are often defined as a part of reliability engineering in Reliability Programs. Reliability plays a key role in the cost-effectiveness of systems, Reliability engineering deals with the estimation, prevention and management of high levels of lifetime engineering uncertainty and risks of failure. Although stochastic parameters define and affect reliability, according to some authors on reliability engineering. You cannot really find a cause by only looking at statistics. Reliability engineering relates closely to safety engineering and to safety, in that they use common methods for their analysis. Reliability engineering focuses on costs of failure caused by system downtime, cost of spares, repair equipment, personnel, Safety engineering normally emphasizes not cost, but preserving life and nature, and therefore deals only with particular dangerous system-failure modes. High reliability levels also result from good engineering and from attention to detail, the word reliability can be traced back to 1816, by poet Coleridge. Before World War II the name has been linked mostly to repeatability, a test was considered reliable if the same results would be obtained repeatedly. The development of reliability engineering was here on a path with quality. The modern use of the reliability was defined by the U. S. military in the 1940s, characterizing a product that would operate when expected. In World War II, many reliability issues were due to inherent unreliability of electronics, in 1945, M. A. Miner published the seminal paper titled Cumulative Damage in Fatigue in an ASME journal. The IEEE formed the Reliability Society in 1948, in 1950, on the military side, a group called the Advisory Group on the Reliability of Electronic Equipment, AGREE, was born. The famous military standard 781 was created at that time, around this period also the much-used military handbook 217 was published by RCA and was used for the prediction of failure rates of components. The emphasis on component reliability and empirical research alone slowly decreases, More pragmatic approaches, as used in the consumer industries, are being used. In the 1980s, televisions were made up of solid-state semiconductors
38.
IBM POWER Instruction Set Architecture
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POWER is a reduced instruction set computer instruction set architecture developed by IBM. The name is an acronym for Performance Optimization With Enhanced RISC, the ISA is used as base for high end microprocessors from IBM during the 1990s and were used in many of IBMs servers, minicomputers, workstations, and supercomputers. These processors are called POWER1 and POWER2, the POWER ISA was then abandoned. In 1974, IBM started a project with an objective of creating a large telephone-switching network with a potential capacity to deal with at least 300 calls per second. It was projected that 20,000 machine instructions would be required to each call while maintaining a real-time response. By 1975 the telephone switch project was canceled without a prototype, watson Research Center building #801, on the 801 project. To increase performance, Cheetah had separate branch, fixed-point, many changes were made to the 801 design to allow for multiple-execution-units. In February 1990, the first computers from IBM to incorporate the POWER instruction set were called the RISC System/6000 or RS/6000 and these RS/6000 computers were divided into two classes, workstations and servers, and hence introduced as the POWERstation and POWERserver. The RS/6000 CPU had 2 configurations, called the RIOS-1 and RIOS.9, a single-chip implementation of RIOS, RSC, was developed for lower-end RS/6000s, the first machines using RSC were released in 1992. IBM started the POWER2 processor effort as a successor to the POWER1 two years before the creation of the 1991 Apple/IBM/Motorola alliance in Austin, Texas, despite being impacted by diversion of resources to jump start the Apple/IBM/Motorola effort, the POWER2 took five years from start to system shipment. By adding a second fixed-point unit, a floating point unit, and other performance enhancements to the design. New instructions were added to the instruction set, Quad-word storage instructions. The quad-word load instruction moves two adjacent double-precision values into two adjacent floating-point registers, P2SC combined all of the separate POWER2 instruction cache, fixed point, floating point, storage control, and data cache chips onto one huge die. At the time of its introduction, P2SC was the largest and highest transistor count processor in the industry, P2SC was the processor used in the 1997 IBM Deep Blue chess playing supercomputer which beat chess grandmaster Garry Kasparov. With its twin sophisticated MAF floating point units and huge wide and low latency memory interfaces, P2SC was primarily targeted at engineering and scientific applications. P2SC was eventually succeeded by the POWER3, which included 64-bit, SMP capability, the POWER design is descended directly from the earlier 801 CPU, widely considered to be the first true RISC processor design. The 801 was used in a number of applications inside IBM hardware, at about the same time the PC/RT was being released, IBM started the America Project, to design the most powerful CPU on the market. They were interested primarily in fixing two problems in the 801 design, The 801 required all instructions to complete in one clock cycle, although the decoder was pipelined as a side effect of these single-cycle operations, they didnt use superscalar effects
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