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List Of Cassette Tape Data Storage Formats
Many early microcomputer and home computer systems used cassette tapes as an inexpensive magnetic tape data storage system. This article lists some of the historically notable formats. As interoperability between platforms was difficult, there was little purpose to, or effort expended on, using standardized formats. The main exception to this rule was the Kansas City standard, which was supported by most S-100 bus based computers and was later adopted by a few other vendors like the BBC Computer and MSX. It also saw use as an exchange medium in some magazines and even broadcast over the radio in Europe. RCA COSMAC One of the earliest efforts to develop a microcomputer for home use was carried out in the early 1970s at RCA and led to the COSMAC processor design. As part of this process, a cassette interface was developed. This used a frequency-shift keying (FSK) system, with binary zeros ("space") represented by one cycle of a 2 kHz signal, and ones ("mark") as a cycle of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers, were comparatively much larger and more expensive (though indeed present-day mainframes such as the IBM System z machines use one or more custom microprocessors as their CPUs). Many microcomputers (when equipped with a keyboard and screen for input and output) are also personal computers (in the generic sense). An early use of the term ''personal computer'' in 1962 predates microprocessor-based designs. ''(See "Personal Computer: Computers at Companies" reference below)''. A ''microcomputer'' used as an embedded control system may have no human-readable input ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembler Code
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an ''assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book ''The Preparation of Programs for an Electronic Digital Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interface Age
''Interface Age'', "published for the home computerist", was a computer magazine aimed at the early microcomputer and home computer market. Its first issue was published in August 1976 and the last one in September 1984. It had a technical focus for most of its print run. The magazine started as the newsletter of the Southern California Computer Society, ''SCCS Interface'', which was first published in December 1975. Its publisher, Robert S. Jones, offered to turn it into a professionally produced magazine and established an agreement with the SCCS in which the SCCS would provide a substantial part of the content of the magazine, while Jones would bear the costs of publishing and marketing, with the SCCS sharing in the profits. However, SCCS failed to produce a necessary flow of content, with Jones eventually providing all of the content through his own writers and columnists. Jones ended all connection with the SCCS, and the magazine became simply ''Interface Age''. Its first issu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Redundancy Check
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on the remainder of a polynomial division of their contents. On retrieval, the calculation is repeated and, in the event the check values do not match, corrective action can be taken against data corruption. CRCs can be used for error correction (see bitfilters). CRCs are so called because the ''check'' (data verification) value is a ''redundancy'' (it expands the message without adding information) and the algorithm is based on ''cyclic'' codes. CRCs are popular because they are simple to implement in binary hardware, easy to analyze mathematically, and particularly good at detecting common errors caused by noise in transmission channels. Because the check value has a fixed length, the function that generates it is occasionally used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Electron
The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/ home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a price more competitive with that of the ZX Spectrum. It had 32 kilobytes of RAM, and its ROM included BBC BASIC II together with the operating system. Announced in 1982 for a possible release the same year, it was eventually introduced on 25 August 1983 priced at £199. The Electron was able to save and load programs onto audio cassette via a supplied cable that connected it to any standard tape recorder that had the correct sockets. It was capable of bitmapped graphics, and could use either a television set, a colour (RGB) monitor or a monochrome monitor as its display. Several expansions were made available to provide many of the capabilities omitted from the BBC Micro. Acorn introduced a general-purpose expansion unit, the Plus 1, off ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC Micro
The British Broadcasting Corporation Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by Acorn Computers in the 1980s for the BBC Computer Literacy Project. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its operating system. An accompanying 1982 television series, ''The Computer Programme'', featuring Chris Serle learning to use the machine, was broadcast on BBC2. After the Literacy Project's call for bids for a computer to accompany the TV programmes and literature, Acorn won the contract with the ''Proton'', a successor of its Atom computer prototyped at short notice. Renamed the BBC Micro, the system was adopted by most schools in the United Kingdom, changing Acorn's fortunes. It was also successful as a home computer in the UK, despite its high cost. Acorn later employed the machine to simulate and develop the ARM architecture. While nine models ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Computers Ltd
The acorn, or oaknut, is the nut of the oaks and their close relatives (genera ''Quercus'' and ''Lithocarpus'', in the family Fagaceae). It usually contains one seed (occasionally two seeds), enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns are long and on the fat side. Acorns take between 5 and 24 months (depending on the species) to mature; see the list of ''Quercus'' species for details of oak classification, in which acorn morphology and phenology are important factors. Etymology The word ''acorn'' (earlier ''akerne'', and ''acharn'') is related to the Gothic name ''akran'', which had the sense of "fruit of the unenclosed land". The word was applied to the most important forest produce, that of the oak. Chaucer spoke of "achornes of okes" in the 14th century. By degrees, popular etymology connected the word both with "corn" and "oak-horn", and the spelling changed accordingly. The current spelling (emerged 15c.-16c.), derives from associat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Processor Technology
Processor Technology Corporation was a personal computer company founded in April 1975 by Gary Ingram and Bob Marsh in Berkeley, California. Their first product was a 4K byte RAM board that was compatible with the Micro Instrumentation and Telemetry Systems, MITS Altair 8800 computer but more reliable than the MITS board. This was followed by a series of memory and I/O boards including a video display module. A Processor Technology advertisement showing a motherboard with eight add-in boards. Popular Electronics magazine wanted a feature article on an intelligent computer terminal and Technical Editor Les Solomon asked Marsh and Lee Felsenstein to design one. It was featured on the July 1976 cover and became the Sol-20 Personal Computer. The first units were shipped in December 1976 and the Sol-20 was a very successful product. The company failed to develop next generation products and ceased operations in May 1979.Freiberger (2000), 153-155 History Bob Marsh, Lee Felsenstein an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manchester Encoding
In telecommunication and data storage, Manchester code (also known as phase encoding, or PE) is a line code in which the encoding of each data bit is either low then high, or high then low, for equal time. It is a self-clocking signal with no DC component. Consequently, electrical connections using a Manchester code are easily galvanically isolated. Manchester code derives its name from its development at the University of Manchester, where the coding was used for storing data on the magnetic drums of the Manchester Mark 1 computer. Manchester code was widely used for magnetic recording on 1600 bpi computer tapes before the introduction of 6250 bpi tapes which used the more efficient group-coded recording. Manchester code was used in early Ethernet physical layer standards and is still used in consumer IR protocols, RFID and near-field communication. Features Manchester coding is a special case of binary phase-shift keying (BPSK), where the data controls the phas ... [...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] |
Kansas City
The Kansas City metropolitan area is a bi-state metropolitan area anchored by Kansas City, Missouri. Its 14 counties straddle the border between the U.S. states of Missouri (9 counties) and Kansas (5 counties). With and a population of more than 2.2 million people, it is the second-largest metropolitan area centered in Missouri (after Greater St. Louis) and is the largest metropolitan area in Kansas, though Wichita is the largest metropolitan area centered in Kansas. Alongside Kansas City, Missouri, these are the suburbs with populations above 100,000: Overland Park, Kansas; Kansas City, Kansas; Olathe, Kansas; Independence, Missouri; and Lee's Summit, Missouri. Business enterprises and employers include Cerner Corporation (the largest, with almost 10,000 local employees and about 20,000 global employees), AT&T, BNSF Railway, GEICO, Asurion, T-Mobile (formerly Sprint), Black & Veatch, AMC Theatres, Citigroup, Garmin, Hallmark Cards, Waddell & Reed, H&R Block, General Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
