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ND812
The 12-bit ND812, produced by Nuclear Data, Inc., was a commercial minicomputer developed for the scientific computing market. Nuclear Data introduced it in 1970 at a price under $10,000 (). Description The architecture has a simple programmed I/O bus, plus a DMA channel. The programmed I/O bus typically runs low to medium-speed peripherals, such as printers, teletypes, paper tape punches and readers, while DMA is used for cathode ray tube screens with a light pen, analog-to-digital converters, digital-to-analog converters, tape drives, disk drives. The word size, 12 bits, is large enough to handle unsigned integers from 0 to 4095 – wide enough for controlling simple machinery. This is also enough to handle signed numbers from -2048 to +2047. This is higher precision than a slide rule or most analog computers. Twelve bits could also store two six-bit characters (note, six-bit isn't enough for two cases, unlike "fuller" ASCII character set). "ND Code" was one such 6-bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12-bit
Possibly the best-known 12-bit CPU is the PDP-8 and its relatives, such as the Intersil 6100 microprocessor produced in various forms from August 1963 to mid-1990. Many analog to digital converters (ADCs) have a 12-bit resolution. Some PIC microcontrollers use a 12-bit word size. 12 binary digits, or 3 nibbles (a 'tribble'), have 4096 (10000 octal, 1000 hexadecimal) distinct combinations. Hence, a microprocessor with 12-bit memory addresses can directly access 4096 words (4 Kw) of word-addressable memory. At a time when six-bit character codes were common a 12-bit word, which could hold two characters, was a convenient size. IBM System/360 instruction formats use a 12-bit displacement field which, added to the contents of a base register, can address 4096 bytes of memory. List of 12-bit computer systems * Digital Equipment Corporation ** PDP-5 ** PDP-8 *** DECmate, a personal computer based on the Intersil 6100 ** PDP-12 ** PDP-14 * Ford EEC I automotive engine control unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Data, Inc
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Nuclear may refer to: Physics Relating to the nucleus of the atom: *Nuclear engineering *Nuclear physics *Nuclear power *Nuclear reactor *Nuclear weapon *Nuclear medicine *Radiation therapy *Nuclear warfare Mathematics *Nuclear space *Nuclear operator *Nuclear congruence *Nuclear C*-algebra Biology Relating to the nucleus of the cell: * Nuclear DNA Society *Nuclear family, a family consisting of a pair of adults and their children Music * "Nuclear" (band), group music. * "Nuclear" (Ryan Adams song), 2002 *"Nuclear", a song by Mike Oldfield from his ''Man on the Rocks'' album * ''Nu.Clear'' (EP) by South Korean girl group CLC See also *Nucleus (other) *Nucleolus *Nucleation *Nucleic acid *Nucular ''Nucular'' is a common, proscribed pronunciation of the word "nuclear". It is a rough phonetic spelling of . The ''Oxford English Dictionary''s entry dates the word's first published appearance to 1943. Dictionary notes This is one of two con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Drive
A tape drive is a data storage device that reads and writes data on a magnetic tape. Magnetic tape data storage is typically used for offline, archival data storage. Tape media generally has a favorable unit cost and a long archival stability. A tape drive provides sequential access storage, unlike a hard disk drive, which provides direct access storage. A disk drive can move to any position on the disk in a few milliseconds, but a tape drive must physically wind tape between reels to read any one particular piece of data. As a result, tape drives have very large average access times. However, tape drives can stream data very quickly off a tape when the required position has been reached. For example, Linear Tape-Open (LTO) supports continuous data transfer rates of up to 360 MB/s, a rate comparable to hard disk drives. Design Magnetic tape drives with capacities of less than one megabyte were first used for data storage on mainframe computers in the 1950s. , capaci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcomp Plotter
Calcomp plotters (sometimes referred to as CalComp plotters) were the best known products of the California Computer Products company ( Calcomp or CalComp). Overview The Calcomp 565 drum plotter, introduced in 1959, was one of the first computer graphics output devices sold. The computer could control in increments the rotation of an wide drum, and the horizontal movement of a pen holder over the drum. The pen was pressed by a spring against paper scrolling across the drum. A solenoid could lift the pen off the paper. This arrangement allowed line drawings to be made under computer control. Later, Calcomp manufactured its model 563, which was very similar but had a wide drum. The paper rolls were long. A metal bar above the take-up reel allowed a finished plot to be torn off and removed. The drum would then be advanced using the manual controls and the fresh paper end taped to the take-up reel. The standard pen was a ball-point, but liquid ink pens were available, and typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centronics
Centronics Data Computer Corporation was an American manufacturer of computer printers, now remembered primarily for the parallel interface that bears its name, the Centronics connector. History Foundations Centronics began as a division of Wang Laboratories. Founded and initially operated by Robert Howard (president) and Samuel Lang (vice president and owner of the well known K & L Color Photo Service Lab in New York City), the group produced remote terminals and systems for the casino industry. Printers were developed to print receipts and transaction reports. Wang spun off the business in 1971 and Centronics was formed as a corporation in Hudson, New Hampshire with Howard as president and chairman. The Centronics Model 101 was introduced at the 1970 National Computer Conference in May. The print head used an innovative seven-wire solenoid impact system. Based on this design, Centronics later developed the first dot matrix impact printer (while the first such printer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pertec Computer
Pertec Computer Corporation (PCC), formerly Peripheral Equipment Corporation (PEC), was a computer company based in Chatsworth, California which originally designed and manufactured peripherals such as floppy drives, tape drives, instrumentation control and other hardware for computers. Pertec's most successful products were hard disk drives and tape drives, which were sold as OEM to the top computer manufacturers, including IBM, Siemens and DEC. Pertec manufactured multiple models of seven and nine track half-inch tape drives with densities 800CPI ( NRZI) and 1600CPI ( PE) and phase-encoding formatters, which were used by myriad original equipment manufacturers as I/O devices for their product lines. In the 1970s, Pertec entered the computer industry through several acquisitions of computer producers and started manufacturing and marketing mostly minicomputers for data processing and pre-processing. This split up Pertec into two companies. Pertec Peripherals Corporation (PPC), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diablo Data Systems
Diablo Data Systems was a division of Xerox created by the acquisition of Diablo Systems Inc. for US$29 million in 1972,Xerox Factbook 2003-2004 , p.43 a company which had been founded in 1969 by George E. Comstock, Charles L. Waggoner and others. The company was best known for the HyType I and HyType II typewriter-based s, the daisywheel printers, as well as removable hard disk drives that were used in the |
Least Significant Bit
In computing, bit numbering is the convention used to identify the bit positions in a binary number. Bit significance and indexing In computing, the least significant bit (LSB) is the bit position in a binary integer representing the binary 1s place of the integer. Similarly, the most significant bit (MSB) represents the highest-order place of the binary integer. The LSB is sometimes referred to as the ''low-order bit'' or ''right-most bit'', due to the convention in positional notation of writing less significant digits further to the right. The MSB is similarly referred to as the ''high-order bit'' or ''left-most bit''. In both cases, the LSB and MSB correlate directly to the least significant digit and most significant digit of a decimal integer. Bit indexing correlates to the positional notation of the value in base 2. For this reason, bit index is not affected by how the value is stored on the device, such as the value's byte order. Rather, it is a property of the numeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Most Significant Bit
In computing, bit numbering is the convention used to identify the bit positions in a binary number. Bit significance and indexing In computing, the least significant bit (LSB) is the bit position in a binary integer representing the binary 1s place of the integer. Similarly, the most significant bit (MSB) represents the highest-order place of the binary integer. The LSB is sometimes referred to as the ''low-order bit'' or ''right-most bit'', due to the convention in positional notation of writing less significant digits further to the right. The MSB is similarly referred to as the ''high-order bit'' or ''left-most bit''. In both cases, the LSB and MSB correlate directly to the least significant digit and most significant digit of a decimal integer. Bit indexing correlates to the positional notation of the value in base 2. For this reason, bit index is not affected by how the value is stored on the device, such as the value's byte order. Rather, it is a property of the numeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Memory
Computer data storage is a technology consisting of computer components and recording media that are used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but less expensive and larger options further away. Generally, the fast volatile technologies (which lose data when off power) are referred to as "memory", while slower persistent technologies are referred to as "storage". Even the first computer designs, Charles Babbage's Analytical Engine and Percy Ludgate's Analytical Machine, clearly distinguished between processing and memory (Babbage stored numbers as rotations of gears, while Ludgate stored numbers as displacements of rods in shuttles). This distinction was extended in the Von Neumann arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are , which severely limited its scope. All modern computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set. The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding. ASCII is one of the List of IEEE milestones, IEEE milestones. Overview ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Six-bit Character Code
A six-bit character code is a character encoding designed for use on computers with word lengths a multiple of 6. Six bits can only encode 64 distinct characters, so these codes generally include only the upper-case letters, the numerals, some punctuation characters, and sometimes control characters. The 7-track magnetic tape format was developed to store data in such codes, along with an additional parity bit. Types of six-bit codes An early six-bit binary code was used for Braille, the reading system for the blind that was developed in the 1820s. The earliest computers dealt with numeric data only, and made no provision for character data. Six-bit BCD, with several variants, was used by IBM on early computers such as the IBM 702 in 1953 and the IBM 704 in 1954. Six-bit encodings were replaced by the 8-bit EBCDIC code starting in 1964, when System/360 standardized on 8-bit bytes. There are some variants of this type of code (see below). Six-bit character codes generally succee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
