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UNIVAC 1050
The UNIVAC 1050 was a variable word-length (one to 16 characters) decimal and binary computer. Instructions were fixed length (30 bits – five characters), consisting of a five-bit "op code", a three-bit index register specifier, one reserved bit, a 15-bit address, and a six-bit "detail field" whose function varies with each instruction. The memory was up to 32K of six-bit characters. Like the IBM 1401, the 1050 was commonly used as an off-line peripheral controller in many installations of both large "scientific computers and large "business computers". In these installations the big computer (e.g., a UNIVAC III) did all of its input-output on magnetic tapes and the 1050 was used to format input data from other peripherals (e.g., punched card readers) on the tapes and transfer output data from the tapes to other peripherals (e.g., punched card punches or the lineprinter). A version used by the U.S. Air Force, the U1050-II real-time system, had some extra peripherals. The m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Word-length (computer Hardware)
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word size'', ''word width'', or ''word length'') is an important characteristic of any specific processor design or computer architecture. The size of a word is reflected in many aspects of a computer's structure and operation; the majority of the registers in a processor are usually word-sized and the largest datum that can be transferred to and from the working memory in a single operation is a word in many (not all) architectures. The largest possible address size, used to designate a location in memory, is typically a hardware word (here, "hardware word" means the full-sized natural word of the processor, as opposed to any other definition used). Documentation for older computers with fixed word size commonly states memory sizes in words ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set
In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, such as a central processing unit (CPU), is called an ''implementation''. In general, an ISA defines the supported instructions, data types, registers, the hardware support for managing main memory, fundamental features (such as the memory consistency, addressing modes, virtual memory), and the input/output model of a family of implementations of the ISA. An ISA specifies the behavior of machine code running on implementations of that ISA in a fashion that does not depend on the characteristics of that implementation, providing binary compatibility between implementations. This enables multiple implementations of an ISA that differ in characteristics such as performance, physical size, and monetary cost (among other things), but that are capable of running the same machine code, so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opcode
In computing, an opcode (abbreviated from operation code, also known as instruction machine code, instruction code, instruction syllable, instruction parcel or opstring) is the portion of a machine language instruction that specifies the operation to be performed. Beside the opcode itself, most instructions also specify the data they will process, in the form of operands. In addition to opcodes used in the instruction set architectures of various CPUs, which are hardware devices, they can also be used in abstract computing machines as part of their byte code specifications. Overview Specifications and format of the opcodes are laid out in the instruction set architecture ( ISA) of the processor in question, which may be a general CPU or a more specialized processing unit. Opcodes for a given instruction set can be described through the use of an opcode table detailing all possible opcodes. Apart from the opcode itself, an instruction normally also has one or more specifiers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Register
An index register in a computer's CPU is a processor register (or an assigned memory location) used for pointing to operand addresses during the run of a program. It is useful for stepping through strings and arrays. It can also be used for holding loop iterations and counters. In some architectures it is used for read/writing blocks of memory. Depending on the architecture it maybe a dedicated index register or a general-purpose register. Some instruction sets allow more than one index register to be used; in that case additional instruction fields may specify which index registers to use. Generally, the contents of an index register is added to (in some cases subtracted from) an ''immediate'' address (that can be part of the instruction itself or held in another register) to form the "effective" address of the actual data (operand). Special instructions are typically provided to test the index register and, if the test fails, increments the index register by an immediate con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 1401
The IBM 1401 is a variable-wordlength decimal computer that was announced by IBM on October 5, 1959. The first member of the highly successful IBM 1400 series, it was aimed at replacing unit record equipment for processing data stored on punched cards and at providing peripheral services for larger computers. The 1401 is considered to be the Ford Model-T of the computer industry, because it was mass-produced and because of its sales volume. Over 12,000 units were produced and many were leased or resold after they were replaced with newer technology. The 1401 was withdrawn on February 8, 1971. History The 1401 project evolved from an IBM project named World Wide Accounting Machine (WWAM), which in turn was a reaction to the success of Bull Gamma 3 (fr). The 1401 was operated as an independent system, in conjunction with IBM punched card equipment, or as auxiliary equipment to IBM 700 or 7000 series systems. Monthly rental for 1401 configurations started at US$2,500 (wort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC III
The UNIVAC III, designed as an improved transistorized replacement for the vacuum tube UNIVAC I and UNIVAC II computers, was introduced in June 1962, with Westinghouse agreeing to furnish system programing and marketing on June 1, 1962. It was designed to be compatible for all data formats. However the word size and instruction set were completely different; this presented significant difficulty as all programs had to be rewritten, so many customers switched to different vendors instead of upgrading existing UNIVACs. The UNIVAC III weighed about . The system was engineered to use as little core memory as possible, as it was a very expensive item. The memory system was 25 bits wide and could be configured with from 8,192 words to 32,768 words of memory. Memory was built in stacks of 29 planes of 4,096 cores: 25 for the data word, two for "modulo-3 check" bits, and two for spares. Each memory cabinet held up to four stacks (16,384 words). It supported the following data formats: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape could with relative ease record and playback audio, visual, and binary computer data. Magnetic tape revolutionized sound recording and reproduction and broadcasting. It allowed radio, which had always been broadcast live, to be recorded for later or repeated airing. Since the early 1950s, magnetic tape has been used with computers to store large quantities of data and is still used for backup purposes. Magnetic tape begins to degrade after 10–20 years and therefore is not an ideal medium for long-term archival storage. Durability While good for short-term use, magnetic tape is highly prone to disintegration. Depending on the environment, this process may begin after 10–20 years. Over time, magnetic tape made in the 197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Punched Card
A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to directly control automated machinery. Punched cards were widely used through much of the 20th century in the data processing industry, where specialized and increasingly complex unit record equipment, unit record machines, organized into semiautomatic data processing systems, used punched cards for data input, output, and storage. The IBM 12-row/80-column punched card format came to dominate the industry. Many early digital computers used punched cards as the primary medium for input of both computer programs and Data (computing), data. While punched cards are now obsolete as a storage medium, as of 2012, some voting machines still used punched cards to record votes. They also had a significant cultural impact. History The idea of contr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lineprinter
A line printer prints one entire line of text before advancing to another line. Most early line printers were impact printers. Line printers are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use. Print speeds of 600 lines per minute (approximately 10 pages per minute) were achieved in the 1950s, later increasing to as much as 1200 lpm. Line printers print a complete line at a time and have speeds in the range of 150 to 2500 lines per minute. The types of line printers are drum printers, band-printers, and chain printers. Other non-impact technologies have also been used, as thermal line printers were popular in the 1970s and 1980s, and some inkjet and laser printers produce output a line or a page at a time. Designs Many impact printers, such as the daisywheel printer and dot matrix printer, used a print head that printed a character then moved on until an entire line was printed. Line printers we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UNIVAC 1050-II
UNIVAC (Universal Automatic Computer) was a line of electronic digital stored-program computers starting with the products of the Eckert–Mauchly Computer Corporation. Later the name was applied to a division of the Remington Rand company and successor organizations. The BINAC, built by the Eckert–Mauchly Computer Corporation, was the first general-purpose computer for commercial use, but it was not a success. The last UNIVAC-badged computer was produced in 1986. History and structure J. Presper Eckert and John Mauchly built the ENIAC (Electronic Numerical Integrator and Computer) at the University of Pennsylvania's Moore School of Electrical Engineering between 1943 and 1946. A 1946 patent rights dispute with the university led Eckert and Mauchly to depart the Moore School to form the Electronic Control Company, later renamed Eckert–Mauchly Computer Corporation (EMCC), based in Philadelphia, Pennsylvania. That company first built a computer called BINAC (BINary Au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FASTRAND
FASTRAND was a magnetic drum mass storage system built by Sperry Rand Corporation (later Sperry Univac) for their UNIVAC 1100 series and 418/490/494 series computers. A FASTRAND subsystem consisted of one or two Control Units and up to eight FASTRAND units. A dual-access FASTRAND subsystem included two complete control units, and provided parallel data paths that allowed simultaneous operations on any two FASTRAND units in the subsystem. Each control unit interfaced to one (optionally two) 1100 Series (36-bit), or 490 Series (30-bit), parallel I/O channels. A voice coil actuator moved a bar containing multiple single track recording heads, so these drums operated much like moving head disk drives with multiple disks. The heads "flew" on self-acting hydrodynamic air bearings. The drums had a plated magnetic recording surface. An optional feature called Fastband included 24 additional tracks with fixed read/write heads. This feature provided rapid access (35 ms. average access time) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contra-rotating
Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. Examples include some aircraft propellers, resulting in the maximum power of a single piston or turboprop engine to drive two propellers in opposite rotation. Contra-rotating propellers are also common in some marine transmission systems, in particular for large speed boats with planing hulls. Two propellers are arranged one behind the other, and power is transferred from the engine via planetary gear transmission. The configuration can also be used in helicopter designs termed coaxial rotors, where similar issues and principles of torque apply. Contra-rotating propellers should not be confused with counter-rotating propellers, a term which describes non-coaxial propellers on separate shafts; one turning clockwise and the other counter-clockwise. Tandem-rotor helicopters such as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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