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Densely Packed Decimal
Densely packed decimal (DPD) is an efficient method for binary encoding decimal digits. The traditional system of binary encoding for decimal digits, known as binary-coded decimal (BCD), uses four bits to encode each digit, resulting in significant wastage of binary data bandwidth (since four bits can store 16 states and are being used to store only 10), even when using packed BCD. Densely packed decimal is a more efficient code that packs three digits into ten bits using a scheme that allows compression from, or expansion to, BCD with only two or three hardware gate delays. The densely packed decimal encoding is a refinement of Chen–Ho encoding; it gives the same compression and speed advantages, but the particular arrangement of bits used confers additional advantages: * Compression of one or two digits (into the optimal four or seven bits respectively) is achieved as a subset of the three-digit encoding. This means that arbitrary numbers of decimal digits (not only multi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Coding
A binary code represents text, computer processor instructions, or any other data using a two-symbol system. The two-symbol system used is often "0" and "1" from the binary number system. The binary code assigns a pattern of binary digits, also known as bits, to each character, instruction, etc. For example, a binary string of eight bits (which is also called a byte) can represent any of 256 possible values and can, therefore, represent a wide variety of different items. In computing and telecommunications, binary codes are used for various methods of encoding data, such as character strings, into bit strings. Those methods may use fixed-width or variable-width strings. In a fixed-width binary code, each letter, digit, or other character is represented by a bit string of the same length; that bit string, interpreted as a binary number, is usually displayed in code tables in octal, decimal or hexadecimal notation. There are many character sets and many character encodings for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Don't Care
In digital logic, a don't-care term (abbreviated DC, historically also known as ''redundancies'', ''irrelevancies'', ''optional entries'', ''invalid combinations'', ''vacuous combinations'', ''forbidden combinations'', ''unused states'' or ''logical remainders'') for a function is an input-sequence (a series of bits) for which the function output does not matter. An input that is known never to occur is a can't-happen term. Both these types of conditions are treated the same way in logic design and may be referred to collectively as ''don't-care conditions'' for brevity. The designer of a logic circuit to implement the function need not care about such inputs, but can choose the circuit's output arbitrarily, usually such that the simplest, smallest, fastest or cheapest circuit results (circuit minimization, minimization) or the power-consumption is minimized. Don't-care terms are important to consider in minimizing logic circuit design, including graphical methods like Karnaugh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Arithmetic
A binary number is a number expressed in the Radix, base-2 numeral system or binary numeral system, a method for representing numbers that uses only two symbols for the natural numbers: typically "0" (zero) and "1" (one). A ''binary number'' may also refer to a rational number that has a finite representation in the binary numeral system, that is, the quotient of an integer by a power of two. The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit, or binary digit. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used by almost all modern computer, computers and computer-based devices, as a preferred system of use, over various other human techniques of communication, because of the simplicity of the language and the noise immunity in physical implementation. History The modern binary number system was studied in Europe in the 16th and 17th centuries by Thoma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Business Machines Corporation
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is a publicly traded company and one of the 30 companies in the Dow Jones Industrial Average. IBM is the largest industrial research organization in the world, with 19 research facilities across a dozen countries; for 29 consecutive years, from 1993 to 2021, it held the record for most annual U.S. patents generated by a business. IBM was founded in 1911 as the Computing-Tabulating-Recording Company (CTR), a holding company of manufacturers of record-keeping and measuring systems. It was renamed "International Business Machines" in 1924 and soon became the leading manufacturer of punch-card tabulating systems. During the 1960s and 1970s, the IBM mainframe, exemplified by the System/360 and its successors, was the world's dominant computing platform, with the company p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) organization, 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE has a corporate office in New York City and an operations center in Piscataway, New Jersey. The IEEE was formed in 1963 as an amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers. History The IEEE traces its founding to 1884 and the American Institute of Electrical Engineers. In 1912, the rival Institute of Radio Engineers was formed. Although the AIEE was initially larger, the IRE attracted more students and was larger by the mid-1950s. The AIEE and IRE merged in 1963. The IEEE is headquartered in New York City, but most business is done at the IEEE Operations Center in Piscataway, New Jersey, opened in 1975. The Australian Section of the IEEE existed between 1972 and 1985, after which it s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Institution Of Electrical Engineers
The Institution of Electrical Engineers (IEE) was a British professional organisation of electronics, electrical, manufacturing, and information technology professionals, especially electrical engineers. It began in 1871 as the Society of Telegraph Engineers. In 2006, it merged with the Institution of Incorporated Engineers and the new organisation is Institution of Engineering and Technology (IET). Notable past presidents have included Lord Kelvin (1889), Sir Joseph Swan (1898) and Sebastian de Ferranti (1910–11). Notable chairmen include John M. M. Munro (1910–11). History The IEE was founded in 1871 as the Society of Telegraph Engineers, changed its name in 1880 to the Society of Telegraph Engineers and Electricians and changed to the Institution of Electrical Engineers in 1888. It was Incorporated by a Royal Charter in 1921. In 1988 the Institution of Electrical Engineers (IEE) merged with the Institution of Electronic and Radio Engineers (IERE), originally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEE Proceedings - Computers And Digital Techniques
''Proceedings of the Institution of Electrical Engineers'' was a series journals which published the proceedings of the Institution of Electrical Engineers. It was originally established as the ''Journal of the Society of Telegraph Engineers'' in 1872, and was known under several titles over the years, such as ''Journal of the Institution of Electrical Engineers'', ''Proceedings of the IEE'' and ''IEE Proceedings''. History The journal was originally established in 1872, as *''Journal of the Society of Telegraph Engineers'' (1872–1880) Then underwent a series of name changes *''Journal of the Society of Telegraph Engineers and of Electricians'' (1881–1882) *''Journal of the Society of Telegraph-Engineers and Electricians'' (1883–1888) Until in 1889 it settled into *''Journal of the Institution of Electrical Engineers'' (1889–1940) The journal remained under that name for over 50 years. From 1926 to 1940, a new journal was started * ''Institution of Electrical Engineers - ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM SQUOZE
SQUOZE (abbreviated as SQZ) is a memory-efficient representation of a combined source and relocatable object program file with a symbol table on punched cards which was introduced in 1958 with the SCAT assembler on the SHARE Operating System (SOS) for the IBM 709. A program in this format was called a ''SQUOZE deck''. It was also used on later machines including the IBM 7090 and 7094. SQUOZE deck A SQUOZE deck contains an encoded binary form of the original assembly language code; SQUOZE decks are converted to absolute machine code and stored in memory by a loader program. Identifier name character encoding In the ''SQUOZE encoding'', identifiers in the symbol table were represented in a 50-character alphabet, allowing a 36-bit machine word to represent six alphanumeric characters plus two flag bits, thus saving two bits per six characters, because the six bits normally allocated for each character could store up to 64 states rather than only the 50 states needed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEC MOD40
RADIX 50 or RAD50 (also referred to as RADIX50, RADIX-50 or RAD-50), is an uppercase-only character encoding created by Digital Equipment Corporation (DEC) for use on their DECsystem, PDP, and VAX computers. RADIX 50's 40-character repertoire (050 in octal) can encode six characters plus four additional bits into one 36-bit machine word (PDP-6, PDP-10/DECsystem-10, DECSYSTEM-20), three characters plus two additional bits into one 18-bit word (PDP-9, PDP-15), or three characters into one 16-bit word (PDP-11, VAX). The actual encoding differs between the 36-bit and 16-bit systems. 36-bit systems In 36-bit DEC systems RADIX 50 was commonly used in symbol tables for assemblers or compilers which supported six-character symbol names from a 40-character alphabet. This left four bits to encode properties of the symbol. For its similarities to the SQUOZE character encoding scheme used in IBM's SHARE Operating System for representing object code symbols, DEC's variant wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decimal128 Floating-point Format
In computing, decimal128 is a decimal floating-point number format that occupies 128 bits in memory. Formally introduced in IEEE 754-2008, it is intended for applications where it is necessary to emulate decimal rounding exactly, such as financial and tax computations. Format The decimal128 format supports 34 decimal digits of significand and an exponent range of −6143 to +6144, i.e. to . Because the significand is not normalized, most values with less than 34 significant digits have multiple possible representations; , etc. This set of representations for a same value is called a '' cohort''. Zero has 12288 possible representations (24576 if both signed zeros are included, in two different cohorts). Encoding of decimal128 values The IEEE 754 standard allows two alternative encodings for decimal128 values: * The binary encoding, based on binary integer decimal (BID): The significand is encoded as an unsigned integer written in binary. * The decimal encoding, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decimal64 Floating-point Format
In computing, decimal64 is a decimal floating-point computer number format that occupies 8 bytes (64 bits) in computer memory. Decimal64 is a decimal floating-point format, formally introduced in the 2008 revision of the IEEE 754 standard, also known as ISO/IEC/IEEE 60559:2011. Format Decimal64 supports 'normal' values that can have 16 digit precision from to , plus 'denormal' values with ramp-down relative precision down to ±1.×10−398, signed zeros, signed infinities and NaN (Not a Number). This format supports two different encodings. The binary format of the same size supports a range from denormal-min , over normal-min with full 53-bit precision to max . Because the significand for the IEEE 754 decimal formats is not normalized, most values with less than 16 significant digits have multiple possible representations; 1000000 × 10−2=100000 × 10−1=10000 × 100=1000 × 101 all have the value 10000. These sets of representations for a same value are called '' c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
