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Bi-quinary Coded Decimal
Bi-quinary coded decimal is a numeral encoding scheme used in many abacuses and in some early computers, including the Colossus. The term ''bi-quinary'' indicates that the code comprises both a two-state (''bi'') and a five-state (''quin''ary) component. The encoding resembles that used by many abacuses, with four beads indicating either 0 through 4 or 5 through 9 and another bead indicating which of those ranges. Several human languages, most notably Fula and Wolof also use biquinary systems. For example, the Fula word for 6, ''jowi e go'o'', literally means ''five lusone''. Roman numerals use a symbolic, rather than positional, bi-quinary base, even though Latin is completely decimal. Examples Several different representations of bi-quinary coded decimal have been used by different machines. The two-state component is encoded as one or two bits, and the five-state component is encoded using three to five bits. Some examples are: * Roman and Chinese abacuses * Stibitz rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code Biquinaer
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication channel or storage in a storage medium. An early example is an invention of language, which enabled a person, through speech, to communicate what they thought, saw, heard, or felt to others. But speech limits the range of communication to the distance a voice can carry and limits the audience to those present when the speech is uttered. The invention of writing, which converted spoken language into visual symbols, extended the range of communication across space and time. The process of encoding converts information from a source into symbols for communication or storage. Decoding is the reverse process, converting code symbols back into a form that the recipient understands, such as English or/and Spanish. One reason for coding is to ena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-out-of-five Code
A two-out-of-five code is a constant-weight code that provides exactly ten possible combinations of two bits, and is thus used for representing the decimal digits using five bits. Each bit is assigned a weight, such that the set bits sum to the desired value, with an exception for zero. According to Federal Standard 1037C: * each decimal digit is represented by a binary numeral consisting of five bits of which two are of one kind, called ''ones'', and three are of the other kind, called ''zeros'', and * the usual weights assigned to the bit positions are 0-1-2-3-6. However, in this scheme, zero is encoded as binary ''01100''; strictly speaking the 0-1-2-3-6 previously claimed is just a mnemonic device. The weights give a unique encoding for most digits, but allow two encodings for 3: 0+3 or 10010 and 1+2 or 01100. The former is used to encode the digit 3, and the latter is used to represent the otherwise unrepresentable zero. The IBM 7070, IBM 7072, and IBM 7074 computers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinary
Quinary (base-5 or pental) is a numeral system with five as the base. A possible origination of a quinary system is that there are five digits on either hand. In the quinary place system, five numerals, from 0 to 4, are used to represent any real number. According to this method, five is written as 10, twenty-five is written as 100 and sixty is written as 220. As five is a prime number, only the reciprocals of the powers of five terminate, although its location between two highly composite numbers ( 4 and 6) guarantees that many recurring fractions have relatively short periods. Today, the main usage of base 5 is as a biquinary system, which is decimal using five as a sub-base. Another example of a sub-base system, is sexagesimal, base 60, which used 10 as a sub-base. Each quinary digit can hold log25 (approx. 2.32) bits of information. Comparison to other radices Usage Many languagesHarald Hammarström, Rarities in Numeral Systems: "Bases 5, 10, and 20 are omni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finger Binary
Finger binary is a system for counting and displaying binary numbers on the fingers of either or both hands. Each finger represents one binary digit or bit. This allows counting from zero to 31 using the fingers of one hand, or 1023 using both: that is, up to 25−1 or 210−1 respectively. Using all ten toes as well would theoretically increase this to 1,048,575, but it seems unlikely that many people have the dexterity for this. Modern computers typically store values as some whole number of 8-bit bytes, making the fingers of both hands together equivalent to 1 bytes of storage—in contrast to less than half a byte when using ten fingers to count up to 10.Since computers typically store data in a minimum size of one whole byte, fractions of a byte are used here only for comparison. Mechanics In the binary number system, each numerical digit has two possible states (0 or 1) and each successive digit represents an increasing power of two. Note: What follows is but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chisanbop
Chisanbop or chisenbop (from Korean ''chi (ji)'' finger + ''sanpŏp (sanbeop)'' calculation 지산법/指算法), sometimes called Fingermath, is an abacus-like finger counting method used to perform basic mathematical operations. According to ''The Complete Book of Chisanbop'' by Hang Young Pai, chisanbop was created in the 1940s in Korea by Sung Jin Pai and revised by his son Hang Young Pai, who brought the system to the United States in 1977. With the ''chisanbop'' method it is possible to display all numbers from 0 to 99 on two hands, and to perform the addition, subtraction, multiplication and division of numbers. The system has been described as being easier to use than a physical abacus for students with visual impairments. Basic concepts Each finger (but not the thumb) of the right hand has a value of one. Holding both hands above the table, press the index finger of the right hand onto the table to indicate "one". Press the index and middle fingers for "two", the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Number
A binary number is a number expressed in the base-2 numeral system or binary numeral system, a method of mathematical expression which uses only two symbols: typically "0" (zero) and "1" ( one). 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 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 Thomas Harriot, Juan Caramuel y Lobkowitz, and Gottfried Leibniz. However, systems related to binary numbers have appeared earlier in multiple cultures including ancient Egypt, China, and India. Leibniz was specifica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary-coded Decimal
In computing and electronic systems, binary-coded decimal (BCD) is a class of binary encodings of decimal numbers where each digit is represented by a fixed number of bits, usually four or eight. Sometimes, special bit patterns are used for a sign or other indications (e.g. error or overflow). In byte-oriented systems (i.e. most modern computers), the term ''unpacked'' BCD usually implies a full byte for each digit (often including a sign), whereas ''packed'' BCD typically encodes two digits within a single byte by taking advantage of the fact that four bits are enough to represent the range 0 to 9. The precise 4-bit encoding, however, may vary for technical reasons (e.g. Excess-3). The ten states representing a BCD digit are sometimes called '' tetrades'' (for the nibble typically needed to hold them is also known as a tetrade) while the unused, don't care-states are named , ''pseudo-decimals'' or ''pseudo-decimal digits''. BCD's main virtue, in comparison to binary posit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnson Counter
A ring counter is a type of counter composed of flip-flops connected into a shift register, with the output of the last flip-flop fed to the input of the first, making a "circular" or "ring" structure. There are two types of ring counters: * A straight ring counter, also known as a one-hot counter, connects the output of the last shift register to the first shift register input and circulates a single one (or zero) bit around the ring. * A twisted ring counter, also called switch-tail ring counter, walking ring counter, Johnson counter, or Möbius counter, connects the complement of the output of the last shift register to the input of the first register and circulates a stream of ones followed by zeros around the ring. Four-bit ring-counter sequences Properties Ring counters are often used in hardware design (e.g. ASIC and FPGA design) to create finite-state machines. A binary counter would require an adder circuit which is substantially more complex than a ring count ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC LARC
The UNIVAC LARC, short for the ''Livermore Advanced Research Computer'', is a mainframe computer designed to a requirement published by Edward Teller in order to run hydrodynamic simulations for nuclear weapon design. It was one of the earliest supercomputers. LARC supported multiprocessing with two CPUs (called ''Computer''s) and an input/output (I/O) Processor (called the ''Processor''). Two LARC machines were built, the first delivered to Livermore in June 1960, and the second to the Navy's David Taylor Model Basin. Both examples had only one ''Computer'', so no multiprocessor LARCs were ever built. The LARC CPUs were able to perform addition in about 4 microseconds, corresponding to about 250 kIPS speed. This made it the fastest computer in the world until 1962 when the IBM 7030 took the title. The 7030 started as IBM's entry to the LARC contest, but Teller chose the simpler Univac over the more risky IBM design. Description The LARC was a decimal mainframe computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parity Bit
A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes), although they can also be applied separately to an entire message string of bits. The parity bit ensures that the total number of 1-bits in the string is even or odd. Accordingly, there are two variants of parity bits: even parity bit and odd parity bit. In the case of even parity, for a given set of bits, the bits whose value is 1 are counted. If that count is odd, the parity bit value is set to 1, making the total count of occurrences of 1s in the whole set (including the parity bit) an even number. If the count of 1s in a given set of bits is already even, the parity bit's value is 0. In the case of odd parity, the coding is reversed. For a given set of bits, if the count of bits with a value of 1 is even, the parity bit value is se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC Solid State
The UNIVAC Solid State was a magnetic drum-based solid-state computer announced by Sperry Rand in December 1958 as a response to the IBM 650. It was one of the first computers to be (nearly) entirely solid-state, using 700 transistors, and 3000 magnetic amplifiers (FERRACTOR) for primary logic, and 20 vacuum tubes largely for power control. It came in two versions, the Solid State 80 (IBM-style 80-column cards) and the Solid State 90 (Remington-Rand 90-column cards). In addition to the "80/90" designation, there were two variants of the Solid State the SS I 80/90 and the SS II 80/90. The SS II series included two enhancements the addition of 1,280 words of core memory and support for magnetic tape drives. The SS I had only the standard 5,000-word drum memory described in this article and no tape drives. The memory drum had a regular access speed AREA and a FAST ACCESS AREA. 4,000 words of memory had one set of R/W heads to access. The programmer was required to keep track of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
