Clean-room Design
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Clean-room Design
Clean-room design (also known as the Chinese wall#Computer science, Chinese wall technique) is the method of copying a design by reverse engineering and then recreating it without infringing any of the copyrights associated with the original design. Clean-room design is useful as a defense against copyright infringement because it relies on independent creation. However, because independent invention is not a defense against patents, clean-room designs typically cannot be used to circumvent patent restrictions. The term implies that the design team works in an environment that is "clean" or demonstrably uncontaminated by any knowledge of the proprietary techniques used by the competitor. Typically, a clean-room design is done by having someone examine the system to be reimplemented and having this person write a specification. This specification is then reviewed by a lawyer to ensure that no copyrighted material is included. The specification is then implemented by a team with no ...
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Chinese Wall
A Chinese wall or ethical wall is an information barrier protocol within an organization designed to prevent exchange of information or communication that could lead to conflicts of interest. For example, a Chinese wall may be established to separate people who make investments from those who are privy to confidential information that could improperly influence the investment decisions. Firms are generally required by law to safeguard insider information and ensure that improper trading does not occur. Etymology Bryan Garner's ''Dictionary of Modern Legal Usage'' states that the metaphor title "derives ''of course'' from the Great Wall of China",, italics added although an alternative explanation links the idea to the screen walls of Chinese internal architecture. The term was popularized in the United States following the stock market crash of 1929, when the U.S. government legislated information separation between investment bankers and brokerage firms, in order to limit ...
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Read-only Memory
Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing software that is rarely changed during the life of the system, also known as firmware. Software applications, such as video games, for programmable devices can be distributed as ROM cartridge, plug-in cartridges containing ROM. Strictly speaking, ''read-only memory'' refers to hard-wired memory, such as diode matrix or a #Solid-state ROM, mask ROM integrated circuit (IC), that cannot be electronically changed after manufacture. Although discrete circuits can be altered in principle, through the addition of Jump wire, bodge wires and the removal or replacement of components, ICs cannot. Correction of errors, or updates to the software, require new devices to be manufactured and to replace the installed device. Floating-gate ROM semiconductor ...
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NEC V20
The NEC V20 is a microprocessor that was designed and produced by NEC. It is both pin compatible and object-code compatible with the Intel 8088, with an instruction set architecture (ISA) similar to that of the Intel 80188 with some extensions. The V20 was introduced in March 1984. Features The V20's die comprised 63,000 transistors; more than double the 29,000 of the 8088 CPU. The chip was designed for a clock duty cycle of 50%, compared to the 33% duty cycle used by the 8088. The V20 has two 16-bit wide internal databuses, allowing two data transfers to occur concurrently. Differences like that meant that a V20 could typically complete more instructions in a given time than an Intel 8088 running at the same frequency. The V20 was fabricated in 2-micron CMOS technology. Early versions ran at speeds of 5, 8, and 10 MHz. In 1990, an upgrade to the fabrication process technology resulted in the V20H and V20HL, with improved performance and reduced power consumption. La ...
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8086
The 8086 (also called iAPX 86) is a 16-bit microprocessor chip designed by Intel between early 1976 and June 8, 1978, when it was released. The Intel 8088, released July 1, 1979, is a slightly modified chip with an external 8-bit data bus (allowing the use of cheaper and fewer supporting ICs),Fewer TTL buffers, latches, multiplexers (although the amount of TTL logic was not drastically reduced). It also permits the use of cheap 8080-family ICs, where the 8254 CTC, 8255 PIO, and 8259 PIC were used in the IBM PC design. In addition, it makes PCB layout simpler and boards cheaper, as well as demanding fewer (1- or 4-bit wide) DRAM chips. and is notable as the processor used in the original IBM PC design. The 8086 gave rise to the x86 architecture, which eventually became Intel's most successful line of processors. On June 5, 2018, Intel released a limited-edition CPU celebrating the 40th anniversary of the Intel 8086, called the Intel Core i7-8086K. History Background In 1972 ...
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Microcode
In processor design, microcode serves as an intermediary layer situated between the central processing unit (CPU) hardware and the programmer-visible instruction set architecture of a computer. It consists of a set of hardware-level instructions that implement the higher-level machine code instructions or control internal finite-state machine sequencing in many digital processing components. While microcode is utilized in Intel and AMD general-purpose CPUs in contemporary desktops and laptops, it functions only as a fallback path for scenarios that the faster hardwired control unit is unable to manage. Housed in special high-speed memory, microcode translates machine instructions, state machine data, or other input into sequences of detailed circuit-level operations. It separates the machine instructions from the underlying electronics, thereby enabling greater flexibility in designing and altering instructions. Moreover, it facilitates the construction of complex multi-step inst ...
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Declaratory Judgment
A declaratory judgment, also called a declaration, is the legal determination of a court that resolves legal uncertainty for the litigants. It is a form of legally binding preventive by which a party involved in an actual or possible legal matter can ask a court to conclusively rule on and affirm the rights, duties, or obligations of one or more parties in a civil dispute (subject to any appeal). The declaratory judgment is generally considered a statutory remedy and not an equitable remedy in the United States, and is thus not subject to equitable requirements, though there are analogies that can be found in the remedies granted by courts of equity.''Samuels v. Mackell'', 401 U.S. 66, 70 (1971) (“Although the declaratory judgment sought by the plaintiffs was a statutory remedy rather than a traditional form of equitable relief, the Court made clear that a suit for declaratory judgment was nevertheless ‘essentially an equitable cause of action,’ and was ‘analogous to ...
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NEC Corp
is a Japanese multinational information technology and electronics corporation, headquartered at the NEC Supertower in Minato, Tokyo, Japan. It provides IT and network solutions, including cloud computing, artificial intelligence (AI), Internet of Things (IoT) platform, and telecommunications equipment and software to business enterprises, communications services providers and to government agencies. NEC has also been the largest PC vendor in Japan since the 1980s when it launched the PC-8000 series; it currently operates its domestic PC business in a joint venture with Lenovo. NEC was the world's fourth-largest PC manufacturer by 1990. Its semiconductors business unit was the world's largest semiconductor company by annual revenue from 1985 to 1992, the second largest in 1995, one of the top three in 2000, and one of the top 10 in 2006. NEC spun off its semiconductor business to Renesas Electronics and Elpida Memory. Once Japan's major electronics company, NEC has largely ...
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Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ...
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Coherent (operating System)
Coherent is a clone of the Unix operating system for IBM PC compatibles and other microcomputers, developed and sold by the now-defunct Mark Williams Company (MWC). Historically, the operating system was a proprietary product, but it became Open-source software, open source in 2015, released under the BSD licenses, BSD-3-Clause license. Development Coherent was not Unix; the Mark Williams Company had no rights to either the Unix trademark or the AT&T Corporation, AT&T/Bell Labs source code. In the early years of its existence, MWC received a visit from an AT&T delegation looking to determine whether MWC was infringing on AT&T Unix property. The delegation included Dennis Ritchie, who concluded that "it was very hard to believe that Coherent and its basic applications were not created without considerable study of the OS code and details of its applications." However, he also stated that: Much of the operating system was written by alumni from the University of Waterloo: Tom ...
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Microsoft Windows
Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sectors of the computing industry – Windows (unqualified) for a consumer or corporate workstation, Windows Server for a Server (computing), server and Windows IoT for an embedded system. Windows is sold as either a consumer retail product or licensed to Original equipment manufacturer, third-party hardware manufacturers who sell products Software bundles, bundled with Windows. The first version of Windows, Windows 1.0, was released on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces (GUIs). The name "Windows" is a reference to the windowing system in GUIs. The 1990 release of Windows 3.0 catapulted its market success and led to various other product families ...
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GNU General Public License
The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first copyleft license available for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. The GPL is more restrictive than the GNU Lesser General Public License, and even more distinct from the more widely used permissive software licenses such as BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domai ...
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ReactOS
ReactOS is a Free and open-source software, free and open-source operating system for i586/amd64 personal computers that is intended to be binary-code compatibility, binary-compatible with computer programs and device drivers developed for Windows Server 2003 and later versions of Microsoft Windows. ReactOS has been noted as a potential open-source drop-in replacement for Windows and has been of interest for its information on undocumented feature, undocumented Windows APIs. ReactOS has been in development since 1996. , it is still considered to be feature-incomplete Software release life cycle#Alpha, alpha software. Therefore, it is recommended by the developers to be used only for evaluation and testing purposes. However, many Windows applications are working, such as Adobe Acrobat, Adobe Reader 9.3, GIMP 2.6, and LibreOffice 5.4.Tests for ...
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