1.
Magnetic tape data storage
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Magnetic tape data storage is a system for storing digital information on magnetic tape using digital recording. Modern magnetic tape is most commonly packaged in cartridges and cassettes, the device that performs writing or reading of data is a tape drive. Autoloaders and tape libraries automate cartridge handling, for example, a common cassette-based format is Linear Tape-Open, which comes in a variety of densities and is manufactured by several companies. Sony announced in 2014 that they had developed a storage technology with the highest reported magnetic tape data density,148 Gbit/in². Initially, magnetic tape for storage was wound on 10. 5-inch reels. This de facto standard for computer systems persisted through the late 1980s. Tape cartridges and cassettes were available as early as the mid-1970s and were used with small computer systems. With the introduction of the IBM3480 cartridge in 1984, large computer systems started to move away from open reel tapes, magnetic tape was first used to record computer data in 1951 on the Eckert-Mauchly UNIVAC I. The UNISERVO drive recording medium was a metal strip of 0. 5-inch wide nickel-plated phosphor bronze. Recording density was 128 characters per inch on eight tracks at a speed of 100 in/s. Of the eight tracks, six were data, one was a parity track, making allowance for the empty space between tape blocks, the actual transfer rate was around 7,200 characters per second. A small reel of mylar tape provided separation from the metal tape, IBM computers from the 1950s used ferrous-oxide coated tape similar to that used in audio recording. IBMs technology soon became the de facto industry standard, magnetic tape dimensions were 0. 5-inch wide and wound on removable reels up to 10.5 inches in diameter. Different tape lengths were available with 1,200 feet and 2,400 feet on mil, during the 1980s, longer tape lengths such as 3,600 feet became available using a much thinner PET film. Most tape drives could support a maximum size of 10.5 inches. CDC used IBM compatible 1/2 inch magnetic tapes, but also offered a 1 inch wide variant, a so-called mini-reel was common for smaller data sets, such as for software distribution. These were 7-inch reels, often with no fixed length—the tape was sized to fit the amount of data recorded on it as a cost-saving measure. Early IBM tape drives, such as the IBM727 and IBM729, were mechanically sophisticated floor-standing drives that used vacuum columns to buffer long u-shaped loops of tape
2.
Sony
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Sony Corporation is a Japanese multinational conglomerate corporation that is headquartered in Kōnan, Minato, Tokyo. Its diversified business includes consumer and professional electronics, gaming, entertainment, the company is one of the leading manufacturers of electronic products for the consumer and professional markets. Sony was ranked 116th on the 2015 list of Fortune Global 500 and these make Sony one of the most comprehensive entertainment companies in the world. The group consists of Sony Corporation, Sony Pictures Entertainment, Sony Interactive Entertainment, Sony Music Entertainment, Sony Financial Holdings and others. Sony is among the Semiconductor sales leaders by year and as of 2013, the companys current slogan is BE MOVED. Their former slogans were make. believe, like. no. other, Sony has a weak tie to the SMFG keiretsu, the successor to the Mitsui keiretsu. Sony began in the wake of World War II, in 1946, Masaru Ibuka started an electronics shop in a department store building in Tokyo. The company had $530 in capital and a total of eight employees, in the following year he was joined by his colleague, Akio Morita, and they founded a company called Tokyo Tsushin Kogyo 東京通信工業. The company built Japans first tape recorder, called the Type-G, in 1958 the company changed its name to Sony. When Tokyo Tsushin Kogyo was looking for a name to use to market themselves, they strongly considered using their initials. The primary reason they did not is that the railway company Tokyo Kyuko was known as TTK, the company occasionally used the acronym Totsuko in Japan, but during his visit to the United States, Morita discovered that Americans had trouble pronouncing that name. Another early name that was tried out for a while was Tokyo Teletech until Akio Morita discovered that there was an American company already using Teletech as a brand name, the name Sony was chosen for the brand as a mix of two words. One was the Latin word sonus, which is the root of sonic and sound, and the other was sonny, a common slang term used in 1950s America to call a boy. In the 1950s Japan sonny boys, was a word into Japanese which connoted smart and presentable young men. The first Sony-branded product, the TR-55 transistor radio, appeared in 1955, at the time of the change, it was extremely unusual for a Japanese company to use Roman letters to spell its name instead of writing it in kanji. The move was not without opposition, TTKs principal bank at the time and they pushed for a name such as Sony Electronic Industries, or Sony Teletech. Akio Morita was firm, however, as he did not want the company tied to any particular industry. Eventually, both Ibuka and Mitsui Banks chairman gave their approval, according to Schiffer, Sonys TR-63 radio cracked open the U. S. market and launched the new industry of consumer microelectronics
3.
Digital Linear Tape
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Digital Linear Tape is a magnetic tape data storage technology developed by Digital Equipment Corporation from 1984 onwards. In 1994, the technology was purchased by Quantum Corporation, who drives and licenses the technology. A variant with higher capacity is called Super DLT, the lower cost value line was initially manufactured by Benchmark Storage Innovations under license from Quantum. DEC launched the TK50 tape drive for the MicroVAX II and PDP-11 minicomputers in 1984 and this used 22-track CompacTape I cartridges, storing 94 MB per cartridge. The TK50 was superseded in 1987 by the TK70 drive and the 48-track CompacTape II cartridge, in 1989, the CompacTape III format was introduced, increasing the number of tracks to 128 and capacity to 2.6 GB. Later drives into the early 1990s improved the data density of the DLTtape III cartridge, the DLTtape IV cartridge was introduced by Quantum in 1994, with increased tape length and data density, initially offering 20 GB per tape. Super DLTtape, originally capable of up to 110 GB, was launched in 2001, DLT uses linear serpentine recording with multiple tracks on half-inch wide tape. The cartridges contain a reel and the tape is pulled out of the cartridge by means of a leader tape attached to the take-up reel inside the drive. The drive leader tape is buckled to the leader during the load process. Tape speed and tension are controlled electronically via the reel motors, the tape is guided by 4 to 6 rollers that touch only the back side of the tape. Tape material is metal particle tape, SDLT adds an optical servo system that reads servo patterns on the back of the tape to keep the data tracks on the front of the tape correctly aligned with the read/write heads. This is important for newer tape media, which have very thin, dLT7000 and 8000 tilt the head forward and backward to reduce crosstalk between adjacent tracks through azimuth, this is called Symmetric Phase Recording. All DLT drives support hardware data compression, all other companies/brands are contractors and/or resellers of these companies. A new naming convention took effect in 2005, calling the performance line DLT-S, DLT includes Write Once Read Many capability. In February 2007, Quantum stopped developing the next generations of DLT drives after insufficient market acceptance of the S4 and V4 drives, shifting its drive strategy to LTO. Once the media has been written to or formatted in a DLT4000 drive and this is because the DLT1/VS series use a different recording format that is not fully supported by the other family. Tapes written in value series drives can typically be read in higher end drives of a similar vintage, Symmetric Phase Recording DLTtape Handbook, Quantum,2001. How to rethread a dropped leader DLT Roadmap at dlttape. com Obituary of Dr. Fred Hertrich, ECMA209 Specification of DLT3
4.
Linear Tape-Open
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Hewlett Packard Enterprise, IBM and Quantum control the LTO Consortium, which directs development and manages licensing and certification of media and mechanism manufacturers. The standard form-factor of LTO technology goes by the name Ultrium, the seventh generation of LTO Ultrium was released in 2015 and can hold 6.0 TB in a cartridge of the same size. Upon introduction, LTO Ultrium rapidly defined the super tape market segment and has consistently been the best-selling super tape format, LTO is widely used with small and large computer systems, especially for backup. Half-inch magnetic tape has been used for storage for more than 60 years. In the mid 1980s, IBM and DEC put this kind of tape into a single reel, although the physical tape was nominally the same size, the technologies and intended markets were significantly different and there was no compatibility between them. IBM called its format 3480 and designed it to meet the requirements of its mainframe products. DEC originally called theirs CompacTape, but later it was renamed DLT, in the late 1980s, Exabytes Data8 format, derived from Sonys dual-reel cartridge 8 mm video format, saw some popularity, especially with UNIX systems. Sony followed this success with their own now-discontinued 8 mm data format, by the late 1990s, Quantums DLT and Sonys AIT were the leading options for high-capacity tape storage for PC servers and UNIX systems. These technologies were tightly controlled by their owners, consequently, there was little competition between vendors and the prices were relatively high. To counter this, IBM, HP and Seagate formed the LTO Consortium, much of the technology is an extension of the work done by IBM at its Tucson lab during the previous 20 years. Around the time of the release of LTO-1, Seagates magnetic tape division was spun off as Seagate Removable Storage Solutions, later renamed Certance, despite the initial plans for two form-factors of LTO technology, only Ultrium was ever produced. In common usage, LTO generally refers to the Ultrium form factor, as of 2015, seven generations of LTO Ultrium technology have been made available and three more are planned. Between generations, there are strict compatibility rules that describe how, notes Data capacity and speed figures above are for uncompressed data. Most manufacturers list compressed capacities on their marketing material, capacities are often stated on tapes as double the actual value, they assume that data will be compressed with a 2,1 ratio. See Compression below and the table above, the units for data capacity and data transfer rates generally follow the decimal SI prefix convention and not the binary prefix convention. Minimum and maximum reading and writing speeds are drive-dependent, in contrast to other tape technologies, an Ultrium cartridge is rigidly defined by a particular generation of LTO technology and cannot be used in any other way. While Ultrium drives are also defined by a generation, they are required to have some level of compatibility with older generations of cartridges. The rules for compatibility between generations of drives and cartridges is as follows, An Ultrium drive can read data from a cartridge in its own generation and the two prior generations
5.
Digital Data Storage
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Digital Data Storage is a computer data storage technology that is based upon the digital audio tape format that was developed during the 1980s. DDS is primarily intended for use as storage, especially for generating backup copies of working data. A DDS cartridge uses tape with a width of 3. 81mm, with the exception of the latest formats, DAT-160 and DAT-320, initially, the tape was 60 meters or 90 meters in length. Advancements in materials technology have allowed the length to be increased significantly in successive versions, a DDS tape drive uses helical scan recording, the same process used by a video cassette recorder. Backward compatibility between newer drives and older cartridges is not assured, for examples, see HPs DDS/DAT Media Compatibility Matrix, at one time, DDS competed against the Linear Tape-Open, Advanced Intelligent Tape, VXA, and Travan formats. However, AIT, Travan and VXA are no longer mainstream, stores up to 1.3 GB uncompressed on a 60 m cartridge or 2 GB uncompressed on a 90 m cartridge. A media recognition system was introduced with DDS-2 drives and cartridges to detect the medium type, from 1993, DDS-1 tapes included the media recognition system marks on the leader tape—a feature indicated by the presence of four vertical bars after the DDS logo. Stores up to 4 GB uncompressed on a 120 m cartridge, stores up to 12 GB uncompressed on a 125 m cartridge. DDS-3 uses PRML to minimize electronic noise for a data recording. DDS-4 stores up to 20 GB uncompressed on a 150 m cartridge and this format is also called DAT40. DAT72 stores up to 36 GB uncompressed on a 170 m cartridge, the DAT72 standard was developed by HP and Certance. It has the same form-factor as DDS-3 and -4 and is referred to as DDS-5. DAT160 was launched in June 2007 by HP, stores up to 80 GB uncompressed, a major change from the previous generations is the width of the tape. DAT160 uses 8 mm wide tape in a slightly thicker cartridge while all versions use 3.81 mm wide tape. Despite the difference in tape widths, DAT160 drives can load DAT-72, native capacity is 80 GB and native transfer rate was raised to 6.9 MB/s, mostly due to prolonging head/tape contact to 180°. Launch interfaces were Parallel SCSI and USB, with SAS interface released later, in November 2009 HP announced the DAT-320 standard, which stores up to 160 GB uncompressed per cartridge. The next format, Gen 8, was canceled, eCMA-139 ISO/IEC10777,1991, Specification of DDS. ECMA-146 ISO/IEC11321,1992, Specification of DATA/DAT, eCMA-150 ISO/IEC11557,1992, Specification of DDS-DC
6.
VXA
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VXA is a tape backup format originally created by Ecrix and now owned by Tandberg Data. After the merger between Ecrix and Exabyte, VXA was produced by Exabyte Corporation, on November 20,2006, Exabyte was purchased by Tandberg Data who has since stopped further development of the format. Exabyte and Ecrix describe the format as packet technology. Since VXA is based on helical scan technology, data is written across the tape from side to side in helical strips, the novel part of VXA packet technology is that each stripe starts with a unique packet ID and ends with an ECC packet checksum. As each stripe is written to tape, it is read back to verify that the write was successful. If the write was not 100% successful the packet can be rewritten at another point on the tape without stopping, when the data is read back, the packets are reassembled into a buffer by their packet ID. The buffer has 3 additional ECCs to ensure data integrity, another aspect of VXA is that there are 2 read heads for each stripe, slightly offset in relation to each other to allow for more flexibility in reading tapes written by other drives. Due to the relatively slow tape speed inherent to helical scan technology, the VXA format competes mainly against the DDS, and DLT-IV formats. Exabyte released two different product lines based on VXA-3 technology, VXA-320 in 2005 and VXA-172 in 2006, VXA-172 drives are limited to 86 GB per tape cartridge, but can be unlocked to remove the limit. VXA-3 was the first helical scan system in production to feature thin film MR heads, Data Capacity figures above are for uncompressed data. Exabyte assumes a 2x compression factor in their marketing material, ECMA222 Specification of ALDC, the data compression standard for VXA-1
7.
8 mm video format
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The 8mm video format refers informally to three related videocassette formats for the NTSC and PAL/SECAM television systems. These are the original Video8 format and its improved successor Hi8 and their user base consisted mainly of amateur camcorder users, although they also saw important use in the professional television production field. In 1985, Sony of Japan introduced the Handycam, one of the first Video8 cameras with commercial success, much smaller than the competitions VHS and Betamax video cameras, Video8 became very popular in the consumer camcorder market. The three formats are very similar, featuring both the same magnetic tape width and near-identical cassette shells, measuring 95 ×62.5 ×15 mm. This gives a measure of compatibility in some cases. One difference between them is in the quality of the tape itself, but the differences lie in the encoding of the video when it is recorded onto the tape. Video8 was the earliest of the three formats, and is entirely analog and it was followed by Hi8, a version with improved resolution. Although this was still analog, some professional Hi8 equipment could store additional digital stereo PCM sound on a reserved track. Digital8 is the most recent 8mm video format and it retains the same physical cassette shell as its predecessors, and can even record onto Video8 or Hi8 cassettes. However, the format in which video is encoded and stored on the tape itself is the entirely digital DV format, some Digital8 camcorders support Video8 and Hi8 with analog sound, but this is not required by the Digital8 specification. In all three cases, a length of 8mm-wide magnetic tape is wound between two spools and contained within a hard-shell cassette and these cassettes share similar size and appearance with the audio cassette, but their mechanical operation is far closer to that of VHS or Betamax videocassettes. Standard recording time is up to 180 minutes for PAL and 120 minutes for NTSC, like most other videocassette systems, Video8 uses a helical-scan 40mm head drum to read from and write to the magnetic tape. The drum rotates at high speed while the tape is pulled along the drums path, because the tape and drum are oriented at a slight angular offset, the recording tracks are laid down as parallel diagonal stripes on the tape. Unlike preceding systems, 8mm did not use a track on the tape to facilitate the head following the diagonal tracks. Instead 8mm recorded a sequence of four sine waves on each video track such that adjacent tracks would produce one of two heterodyne frequencies if the head mistracked, the system automatically adjusted the tracking such that the two frequencies produced were of equal magnitude. This system was derived from the track following used by the Philips Video 2000 system. Sony rechristened the system as automatic track following as the 8mm system lacked the ability of the heads to physically move within the head drum. The main disadvantage of the ATF system was that unlike in the case of a control track and this made editing using a non linear editing system problematic
8.
Helical scan
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Helical scan is a method of recording high frequency signals on magnetic tape. It is used in video tape recorders, video cassette recorders, digital audio tape recorders. In a fixed tape head recording system, magnetic tape is drawn past the head at a constant speed. The head creates a magnetic field in response to the signal to be recorded. As the tape moves away, the magnetic particles carry an imprint of the signal in their magnetic orientation. If the tape moves too slowly, a frequency signal will not be imprinted. Thus the bandwidth capacity of the recorded signal can be seen to be related to tape speed, the faster the speed. Digital video and digital audio need considerably more bandwidth than analog audio and this is impractical, since tapes of immense length would be required. The generally adopted solution is to rotate the head against the tape at high speed, so that the velocity is high. To accomplish this, the head must be tilted so that at each rotation of the head, each segment of the signal is recorded as a diagonal stripe across the tape. This is known as a helical scan because the tape wraps around the drum at an angle. The difference between the writing speed and linear tape speed is vast, for example,13 mph versus 35 mm/s. The helical scan method of recording was first developed by Eduard Schüller, with the advent of television broadcasting in Japan in the early 1950s, they saw the need for magnetic television signal recording just as engineers in the United States and Europe did. Thus, when tape motion was stopped, only a segment of the picture recording was present at the playback heads. The motivation to overcome this limitation led, in part, to the development of the helical scan system, toshiba introduced helical scan technology to the television industry in 1959. During the 1960s and 1970s, helical scan recording machines were introduced by many manufacturers and these factors also made it possible eventually to bring video recording to users at home, in a cassette format. There were a number of problems to be overcome with this system, the high tape/head speed could lead to rapid wear of both the tape and the head, so both need to be highly polished, and the head made of a hard, wear resistant material. Most systems operate with an air bearing separating the heads from the surface of the drum, supplying signals to a rotating head is also problematic, This is usually accomplished by coupling the signal inductively through a rotary transformer
9.
Hewlett-Packard
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The Hewlett-Packard Company or shortened to Hewlett-Packard was an American multinational information technology company headquartered in Palo Alto, California. The company was founded in a garage in Palo Alto by William Bill Redington Hewlett and David Dave Packard. HP was the worlds leading PC manufacturer from 2007 to Q22013 and it specialized in developing and manufacturing computing, data storage, and networking hardware, designing software and delivering services. HP also had services and consulting business around its products and partner products.4 billion in 2008, in November 2009, HP announced the acquisition of 3Com, with the deal closing on April 12,2010. On April 28,2010, HP announced the buyout of Palm, on September 2,2010, HP won its bidding war for 3PAR with a $33 a share offer, which Dell declined to match. On October 6,2014, Hewlett-Packard announced plans to split the PC and printers business from its enterprise products, the split closed on November 1,2015, and resulted in two publicly traded companies, HP Inc. and Hewlett Packard Enterprise. William Redington Hewlett and David Packard graduated with degrees in engineering from Stanford University in 1935. The company originated in a garage in nearby Palo Alto during a fellowship they had with a past professor, Terman was considered a mentor to them in forming Hewlett-Packard. In 1939, Packard and Hewlett established Hewlett-Packard in Packards garage with a capital investment of US$538. Hewlett and Packard tossed a coin to decide whether the company they founded would be called Hewlett-Packard or Packard-Hewlett, HP incorporated on August 18,1947, and went public on November 6,1957. Of the many projects they worked on, their very first financially successful product was an audio oscillator. This allowed them to sell the Model 200A for $54.40 when competitors were selling less stable oscillators for over $200, the Model 200 series of generators continued until at least 1972 as the 200AB, still tube-based but improved in design through the years. They worked on technology and artillery shell fuses during World War II. Hewlett-Packards HP Associates division, established around 1960, developed semiconductor devices primarily for internal use, instruments and calculators were some of the products using these devices. HP partnered in the 1960s with Sony and the Yokogawa Electric companies in Japan to develop several high-quality products, the products were not a huge success, as there were high costs in building HP-looking products in Japan. HP and Yokogawa formed a joint venture in 1963 to market HP products in Japan, HP bought Yokogawa Electrics share of Hewlett-Packard Japan in 1999. HP spun off a company, Dynac, to specialize in digital equipment. The name was picked so that the HP logo hp could be turned upside down to be a reverse image of the logo dy of the new company
10.
Giant magnetoresistance
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Giant magnetoresistance is a quantum mechanical magnetoresistance effect observed in multilayers composed of alternating ferromagnetic and non-magnetic conductive layers. The 2007 Nobel Prize in Physics was awarded to Albert Fert, the effect is observed as a significant change in the electrical resistance depending on whether the magnetization of adjacent ferromagnetic layers are in a parallel or an antiparallel alignment. The overall resistance is low for parallel alignment and relatively high for antiparallel alignment. The magnetization direction can be controlled, for example, by applying a magnetic field. The effect is based on the dependence of electron scattering on the spin orientation, the main application of GMR is magnetic field sensors, which are used to read data in hard disk drives, biosensors, microelectromechanical systems and other devices. GMR multilayer structures are used in magnetoresistive random-access memory as cells that store one bit of information. Magnetoresistance is the dependence of the resistance of a sample on the strength of an external magnetic field. Numerically, it is characterized by the value δ H = R − R R where R is the resistance of the sample in a magnetic field H, and R corresponds to H =0. Alternative forms of expression may use electrical resistivity instead of resistance, a different sign for δH. The term giant magnetoresistance indicates that the value δH for multilayer structures significantly exceeds the anisotropic magnetoresistance, GMR was discovered in 1988 independently by the groups of Albert Fert of the University of Paris-Sud, France, and Peter Grünberg of Forschungszentrum Jülich, Germany. The practical significance of this discovery was recognized by the Nobel Prize in Physics awarded to Fert. The first mathematical model describing the effect of magnetization on the mobility of carriers in solids. Experimental evidence of the enhancement of δH has been known since the 1960s. By the late 1980s, the anisotropic magnetoresistance had been well explored, Fert and Grünberg studied electrical resistance of structures incorporating ferromagnetic and non-ferromagnetic materials. In particular, Fert worked on films, and Grünberg in 1986 discovered the antiferromagnetic exchange interaction in Fe/Cr films. The GMR discovery work was carried out by the two groups on slightly different samples, the Grünberg work was performed on multilayers of Fe and Cr on GaAs at room temperature. Changing the thickness of the non-magnetic layers led to a significant reduction of the magnetization in the hysteresis loop. The Grünberg experiment made the discovery but the effect was less pronounced due to the samples being at room temperature rather than low temperature
11.
LINC
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The LINC is a 12-bit, 2048-word computer. The LINC is considered the first minicomputer and a forerunner to the personal computer, originally named the Linc, suggesting the projects origins at MITs Lincoln Laboratory, it was renamed LINC after the project moved from the Lincoln Laboratory. The LINC was designed by Wesley A. Clark and Charles Molnar, the LINC and other MIT Group machines were designed at MIT and eventually built by Digital Equipment Corporation and Spear Inc. of Waltham, Massachusetts. The LINC sold for more than $40,000 at the time, a typical configuration included an enclosed 6X20 rack, four boxes holding tape drives, a small display, a control panel, and a keyboard. Although the LINCs instruction set was small, it was larger than the tiny PDP-8 instruction set, the LINC interfaced well with laboratory experiments. Analog inputs and outputs were part of the basic design and it was designed in 1962 by Charles Molnar and Wesley Clark at Lincoln Laboratory, Massachusetts, for NIH researchers. The LINCs design was literally in the domain, perhaps making it unique in the history of computers. The number of LINCs and who built them is a subject of debate in the 12-bit-word community. One account states that a dozen LINC computers were assembled by their eventual biologist users in a 1963 summer workshop at MIT, Digital Equipment Corporation and Spear Inc. of Waltham, MA. manufactured them commercially. DECs pioneer C. Gordon Bell states that the LINC project began in 1961, with first delivery in March 1962, a total of 50 were built, most at Lincoln Labs, housing the desktop instruments in four wooden racks. The first LINC included two oscilloscope displays, twenty-one were sold by DEC at $43,600, delivered in the Production Model design. The standard program development software was designed by Mary Allen Wilkes, the LINC control panel was used for single-stepping through programs and for program debugging. Execution could be stopped when the program counter matched a set of switches, another function allowed execution to be stopped when a particular address was accessed. The single-step and the functions could be automatically repeated. The repetition rate could be varied over four orders of magnitude by means of an analog knob, running a program at one step per second and gradually accelerating it to full speed provided an extremely dramatic way to experience and appreciate the speed of the computer. A noteworthy feature of the LINC was the LINCtape and it was a fundamental part of the machine design, not an optional peripheral, and the machines OS relied on it. The LINCtape can be compared to a linear diskette with a slow seek time, the magnetic tape drives on large machines of the day stored large quantities of data, took minutes to spool from end to end, but could not reliably update blocks of data in place. The tape was formatted in fixed-sized blocks, and was used to hold a directory, a single hardware instruction could seek and then read or write multiple tape blocks all in one operation
12.
DECtape
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DECtape was a magnetic tape data storage medium used with many Digital Equipment Corporation computers, including the PDP-6, PDP-8, LINC-8, PDP-9, PDP-10, PDP-11, PDP-12, and the PDP-15. On DECs 32-bit systems, VAX/VMS support for it was implemented, DECtapes were 3/4 inch wide, and formatted into blocks of data that could each be read or written individually. Each tape stored 184K 12-bit PDP-8 words or 144K 18-bit words, block size was 128 12-bit words, or 256 18-bit words for the other machines. From a programming point of view, DECtape behaved like a very slow disk drive, DECtape had its origin in the LINCtape tape system, which was originally designed by Wesley Clark at the MIT Lincoln Laboratory as an integral part of the LINC computer. There were simple LINC instructions for reading and writing tape blocks using a machine instruction. The design of the LINC, including LINCtape, was placed in the domain because its development had been funded by the government. LINCtape drives were manufactured by companies, including Digital. In turn, LINCtapes origin can be found in the magnetic tape system for the historic Lincoln Laboratory TX-2 computer, designed by Richard L. The TX-2 Tape System is the ancestor of LINCtape, including the use of two redundant sets of five tracks and a direct drive tape transport, but it used a physically incompatible tape format. Digital initially introduced the Type 550 Microtape Control and Type 555 Dual Microtape Transport as peripherals for the PDP-1 and PDP-4 computers, the initial specifications for the Type 550 controller discussed a significant advance beyond the LINCtape, the ability to read and write in either direction. By late 1964, the Type 555 transport was being marketed as a DECtape transport, the tape transport used on the LINC was essentially the same as the Type 555 transport, with the same interface signals and the same physical tape medium. The LINC and DEC controllers, however, were incompatible, while LINCtape supported high-speed bidirectional block search, it only supported actual data read and write operations in the forward direction. DECtape used a different mark track format to provide for the possibility of read and write operations in either direction. DEC applied for a patent on the features incorporated into DECtape in late 1964. It is notable that the inventor listed on this patent, Thomas Stockebrand, was also an author of the paper on the TX-2 tape system from which the LINC tape was derived. Eventually, the TC12-F tape controller on the PDP-12 supported both LINCtape and DECtape on the same transport, as with the earlier LINC-8, the PDP-12 was a PDP-8 augmented with hardware support for the LINC instruction set and associated laboratory peripherals. DECtape was designed to be reliable and durable enough to be used as the storage medium for a computers operating system. It was possible, although slow, to use a DECtape drive to run a small OS such as OS/8 or OS/12
13.
IBM 7 track
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IBMs first magnetic tape data storage devices, introduced in 1952, use what is now generally known as 7 track tape. The magnetic tape is 1/2 wide and there are six tracks plus one parity track for a total of seven parallel tracks that span the length of the tape. Data is stored as six-bit characters, with bit of the character. These tape drives were mechanically sophisticated floor-standing drives that used vacuum columns to buffer long U-shaped loops of tape, between active control of powerful reel motors and vacuum control of these U-shaped tape loops, extremely rapid start and stop of the tape at the tape-to-head interface could be achieved. When active, the two tape reels thus fed tape into or pulled out of the vacuum columns, intermittently spinning in rapid. Stock shots of such vacuum-column tape drives in motion were used to represent the computer in films. Density Initial recording density was 100 characters per inch, later models supported 200,556 and 800 characters per inch. Inter-record Gap A gap between records allowed the time to start and stop the tape. Latency There was only a 1. 5ms delay for the tape to reach its full reading or writing speed. Markers Aluminum strips were glued several feet from the ends of the tape to serve as logical beginning, write protection A removable plastic ring in the back of the tape reel was inserted to indicate writing should be permitted. The IBM726 dual magnetic tape reader/recorder for the IBM701 was announced on May 21,1952, the IBM727 Magnetic Tape Unit was announced for the IBM701 and IBM702 on September 25,1953. It became IBMs standard tape drive for their vacuum tube era computer systems and it was withdrawn on May 12,1971. The IBM728 magnetic tape drive was used on the SAGE AN/FSQ-7 computer and it was physically similar to the IBM727, but with significantly different specifications. Tracks,6 Data,1 synchronization words,6 chars words/inch,41.33 The IBM729 Magnetic Tape Unit was IBMs iconic tape mass storage system from the late 1950s through the mid-1960s and it was used on late 700, most 7000 and many 1400 series computers. A new dual gap head assembly allowed read-after-write verification, the IBM7330 Magnetic Tape Unit was a low cost slower tape system. It was common on 1400 series computers, the 2400 Series Magnetic Tape Units were introduced with the System/360. Most were IBM9 Track format drives, but they could be ordered with seven-track read/write heads, allowing them to read and write seven-track tapes
14.
9 track tape
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The IBM System/360, released in 1964, introduced what is now generally known as 9 track tape. Data is stored as 8-bit characters, spanning the width of the tape. Various recording methods were employed during its lifetime as tape speed and data density increased, including PE, GCR, tapes came in various sizes up to 3,600 feet in length. The standard size of a byte was effectively set at eight bits with the S/360, the control electronics would then indicate to the controlling computer that the unit was ready for operation. Like its audio counterpart, moving tape past the heads on nine-track digital required precise control. The capstan motor was designed for smooth operation. Feedback to the electronics was accomplished by a tachometer, usually an optical tone wheel. Starting and stopping the capstan was controlled by ramp generators to ensure a properly sized inter-record gap, the vacuum columns were chambers open at one end, the openings being in line with the tape path before and after the capstan and roller assemblies. The amount of tape in the column was controlled by four optical or vacuum sensors on the sides of the columns. The control electronics kept the curve of the loop between the two inner sensors, cueing the supply reel to feed more or the take-up reel to take more as necessary. Tape motion on many systems was bidirectional, i. e. tape could be either forward or backward at the request of the controlling computer. Because the supply vacuum column kept a small, constant tension in the reverse direction, unlike most audio tape systems, the capstan and head assemblies were always in contact with the tape, even during fast forward and rewind operations. Tapes included an end-of-tape foil strip, when EOT was encountered while writing, the computer program would be notified of the condition. This gave the program a chance to write information on the tape while there was still enough tape to do so. The sensing of BOT and EOT was achieved by shining a small lamp at the surface at an oblique angle. When the foil strip moved past the lamp a photo-receptor would see the flash of light. This is the reason that photographic flash cameras were not allowed in data centers since they could trick the tape drives into falsely sensing BOT and EOT. The above describes a typical system, however, manufacturers engineered many alternative designs
15.
IBM 3480 Family
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The 3480 tape format is a magnetic tape data storage format developed by IBM. The tape is one inch wide and is packaged in a 4x5x1 cartridge. The cartridge contains a single reel, the reel is inside the tape drive. Because of their speed, reliability, durability and low media cost, a hallmark of the genre is transferability. Tapes recorded with one drive are generally readable on another drive. Tape drives conforming with the IBM3480 product family specification were manufactured by a variety of vendors from 1984 to 2004, core manufacturers included IBM, Fujitsu, M4 Data, Overland Data, StorageTek and Victor Data Systems. Various models of tape drives were also marketed under other brands, including DEC, MP Tapes, Philips, Plasmon, Qualstar, Tandem. IBM designated all versions of 3480 and 3490E tape drives as members of the 3480 Product Family, tape drives built for the 3480 were initially designed for IBM System/370 computers. Therefore, the first 3480 tape drives communicated through a bus, later models were able to take advantage of ESCON and high voltage SCSI interfaces. The advent of the SCSI interface made it possible to connect 3480 family tape drives to personal computers, the first 3480 tape drives were introduced in 1984. The IBM3480 was the first tape drive to employ thin-film heads and it was also distinguished by a relatively high data transfer rate,3 megabytes per second. This was because it was able to read and write data across 18 recording tracks simultaneously. IBMs prior technology employed 9 recording tracks with a density of 6,250 bytes per inch of tape. The IBM3480 cartridge stored 200 megabytes in a modest 4x5 inch cartridge compared to the previous technologys 140 megabytes on a 10.5 inch diameter reel of 1/2 tape, the 3480 and its successors are streaming drives. The streaming drives would then have to stop, back up and restart, while IBM offered 3480 tape drives with bus and tag interfaces, other manufacturers sold models with SCSI interfaces. In 1986, IBM added a data compression option, Improved Data Recording Capability. A3480 tape drive with IDRC could record up to 400 megabytes on a single tape, the 3480 IDRC format is also commonly known as the 3490 recording format. A3480 tape drive with IDRC uses the data cartridges as a standard 3480 tape drive
16.
IBM 3590
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The IBM3590 is a series of tape drives and corresponding magnetic tape data storage media formats developed by IBM. The first drive, having the IBM product number 3590, was introduced in 1995 under the nickname Magstar, the 3590 series of tape drives and media are not compatible with the IBM3592 line of drives that replaced it. They can store up to 60 GB of data and this family superseded the IBM3480 Family of tape drives popular in 1980s and 1990s. Like the 3480 and 3592 formats, this format has half inch tape spooled onto 4-by-5-by-1 inch data cartridges containing a single reel. A takeup reel is embedded inside the tape drive, because of their speed, reliability, durability and low media cost, the 3590 tape drives are still in high demand. A hallmark of the genre is interchangeability, Tapes recorded with one drive are generally readable on another drive. Magstar tapes and drives exist in 128,256 and 384-track versions and it is important to be aware that the tape is written at the drives defined density and can only be read in a drive of the same model type or a higher version model. So a tape written in the H drive can only be read in an H drive, a tape written in an E drive can be read in an E drive and an H drive. A tape written in a B drive can be read in a B, E or H drive, unlike DLT, LTO or 3592 drive variants, the 3590 drive is not capable of writing at a lower density than its native density. There is often confusion in naming of the media and drives, there are two types of media, the standard length media often being referred to as 3590 or 3590B, and the extended length media often being referred to as 3590E. Both types of media can be written in all three drives, the 3590E in the Ultra variant of the 3590B drive,3590 B Model,128 tracks, up to 9 MB/s native data rate. 3590 E Model,256 tracks, up to 14 MB/s native data rate,3590 H Model,384 tracks, up to 14 MB/s native data rate. IBMs 3590 A14 archive product page IBM Redbook for original 3590 model The 320 m long High Performance 3590 cartridges use Polyethylene terephthalate as the base material, the 634 m long Extended 3590 cartridges use Polyethylene naphthalate as the base material. 3590 media datasheet Fifty years of storage innovation Read/Write Compatibility Matrix PC Magazines Magstar Reference
17.
StorageTek tape formats
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Storage Technology Corporation created several magnetic tape data storage formats. These are commonly used with computer systems, typically in conjunction with a robotic tape library. The most recent format is the T10000, StorageTek primarily competed with IBM in this market, and continued to do so after its acquisition by Sun Microsystems in 2005 and again by Oracle in 2009. Most modern tape cartridges are 1⁄2 in format tape, first popularized by the IBM3480 and this is a small, rectangular and easily handled tape cartridge compared to the previously common 7-track and 9-track round tape reels. This form factor has proven to work well with stand alone drives, the mechanical design of this loading mechanism varies between different types of tape media and is a common source of failures. Usually the tape cartridge incorporates a switch that can be set to permit or forbid writing of data to the tape and this process could be repeated many times, laying down several track sets on the tape media in a serpentine recording mode. The Storage Tek 9840,9940 and T10000 drives are all serpentine recording drives, the Storage Tek SD3 drive was different, being based upon a modified video recording device. The Storage Tek 9840 series of drives used an unusual dual tape hub mechanism within the 3480 format shell. This reduced the length of tape that could be stored inside the shell and these tape formats are popular in mainframe environments. Drives used ESCON, FICON, Fibre Channel, or SCSI interfaces and this format used helical scan on a 1/2 inch tape. The drive was based on a professional Panasonic video recording system, the result was a large, heavy drive of considerable complexity. Although somewhat difficult to maintain, it won popularity among some users due to the low cost of the media per Gigabyte. The T10000 is the latest Oracle/Sun StorageTek tape drive and cartridge product line for mainframe systems, the first model, the T10000, has a native capacity of 500 GB and a native transfer rate of 120 MB/s. This line has seen several updates, the first being the T10000B drive, in January 2011, the T10000C tape drive was introduced, along with a new tape cartridge—the T10000 T2—capable of storing 5 TB of data natively. The T10000D drive was announced in September 2013 with a native, the T10000E drive is expected in 2017 with capacity in the 12-16 TB range
18.
Travan
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Travan is an 8 mm magnetic tape cartridge design developed by the 3M company, used for the storage of data in computer backups and mass storage. Over time, subsequent versions of Travan cartridges and drives have been developed that provide greater data capacity, Travan is standardized under the QIC body. HP Colorado, Iomega DittoMax and AIWA Bolt are proprietary versions of the Travan format, the Travan format competes mainly against the DDS, AIT, and VXA formats. Travan TR-1 cartridges offer a 400 MB native capacity with a 0.25 MB/s transfer rate using the QIC-80 media format, tR-2 was designed by 3M, but they never marketed it. TR-2 cartridges were designed to have an 800 MB native capacity with a 0.25 MB/s transfer rate using the QIC-3010 media format, the spec called for 50 tracks across the tape, with a recording density of 22,125 flux transitions per inch. Travan TR-3 cartridges offer a 1.6 GB native capacity with a 0.5 MB/s transfer rate using the QIC-3020 media format, Travan TR-4 cartridges offer a 4 GB native capacity using the QIC-3095 media format. Travan 8 GB cartridges offer a 4 GB native capacity with a 1.2 MB/s transfer rate, Travan NS8 cartridges offer a 4 GB native capacity with a 1.2 MB/s transfer rate. Imation HP Colorado 5 GB is a 460 ft variation on the TR-4 standard and it offered 2.5 GB native capacity,1 MB/s transfer rate. Travan NS20 cartridges offer a 10 GB native capacity with a 2 MB/s transfer rate, Travan 20 GB cartridges offer a 10 GB native capacity with a 2 MB/s transfer rate. Travan 40 GB cartridges offer a 20 GB native capacity with a 4 MB/s transfer rate, Travan uses a linear track technology, with data written onto individual tracks over several successive passes. Fully reading or writing a tape to full capacity may require moving the tape from reel to reel many times, the tape is not attached to the hubs, but is wrapped and held by friction. It also uses an indirect drive system, consisting of an elastic band that presses on the exterior of both reels, and also over an idler wheel on the edge of the case. A motor in the contacts the idler to move the tape. Because the reels wind and unwind at unequal speeds there is always some slippage occurring when the tape is in motion, old tapes used many times tend to have a visibly marked stripe down the center of the tape where the band has pressed into the tape. Unlike some competing technologies such as Digital Linear Tape and Linear Tape-Open, Data verification must be done separately by the computer operator, to verify data was written successfully. If a separate verify operation is not performed after each backup, it is possible for backups to be found to be corrupt, Imation - Travan Data Cartridges Imation - Flyer with cartridge specs
19.
Quarter-inch cartridge
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Quarter inch cartridge tape is a magnetic tape data storage format introduced by 3M in 1972, with derivatives still in use as of 2016. QIC comes in a rugged enclosed package of aluminum and plastic that holds two tape reels driven by a belt in direct contact with the tape. The tape was originally 1⁄4-inch wide and anywhere from 300 to 1,500 feet long, since the introduction of QIC, it has been widely used and many variations exist. There is a QIC trade association that publishes QIC standards which include interfaces, to a very large extent it was the efficiency and openness of this organization which encouraged hardware and software developers to use this type of drive and media. The QIC cartridge is distinguished from other types of cartridges by the fact that it contains an endless drive belt which is moved at a uniform speed by a motorised capstan. Since the belt is in contact with the tape, this ensures both that the moves at uniform speed, and that neutral tension is maintained at all times. This is in contrast to cassette tapes or DATs where the tape is moved past the head by a capstan and pinch wheel, the tape in a QIC cartridge is not physically attached to the reels and is never completely unwound. This is again different from other cassettes or cartridges, which generally have some form of clip anchoring on at least one end of the tape. To ensure that the tape is never completely unwound, each end has a beginning or end of tape hole which is detected by an optical sensor. If a defective drive—for example with fluff in a sensor—winds the tape past the BOT or EOT marker, the tape will detach from the spool, however, because the tape is belt-driven, seeking back and forth can eventually cause the tape to become unevenly tensioned. It is therefore necessary to periodically retension the cartridge and this is accomplished by winding the tape from beginning to end and back in one operation, allowing the belt to equalize itself. For newer QIC drives that use a SCSI interface, there is a SCSI RETENSION command to do this, when the cartridge gets old, the belt may not provide enough friction to turn the takeup spool smoothly. When this happens, the tape will need to be replaced, in some cases a cartridge must be formatted before use. The capability to do this is in the rather than the host computer. The first QIC tape format was the 5.875 in by 3.875 in Data Cartridge format with two internal belt-driven reels and a metal base. The original product, the DC300, has 300 feet of tape and holds 200 kilobytes. 35GB on a DC9135 cartridge Other QIC DC standards include the QIC-02, later QIC DC drives usually use the SCSI interface. Later, the smaller Minicartridge form-factor was introduced and this is 2.375 in by 3.125 in size and is small enough to fit in a 3.5 in drive bay. Travan is an evolution of the QIC Minicartridge format, sold for computer use
20.
Ditto (drive)
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The Ditto drive series was a proprietary magnetic tape data storage system released by Iomega during the 1990s. It was marketed as a device for personal computers. They were released in capacities ranging from the original Ditto 250 drive to the DittoMAX drive. This was accomplished by increasing the size of the cartridge. Some versions of the drive were also able to read Travan-type tapes, Ditto internal drives were connected through the floppy drive channel and used MFM encoding to store data. An ISA accelerator card called the Ditto Dash, providing higher speed than a floppy controller, was also available. Ditto external drives were connected to the port and offered a print-through port which allowed a printer to operate while daisy-chained to the Ditto drive. This is a feature commonly found on an Iomega ZIP drive. Usage of the port allowed for transfer speeds of a maximum 1 MB/s. In 1999, Iomega sold the Ditto brand and technology to Tecmar, the Ditto series has been discontinued. The need for higher capacities has made the Ditto series obsolete, the slow bandwidth of the Ditto also limited its usefulness compared to the Iomega REV or the older Iomega Jaz. Tape 250 - Released in 1992, compatible with Irwins EZTape Notes, R - read capable W - write capable F - format capable The capacity figures used in the product names above are double the actual capacity. Iomega and other manufacturers assume 2,1 data compression, Ditto Max requires version 3.2 Pro of the Iomega backup software to support the Ditto Max 10GB tape cartridge. Tape drive Tape Standards and Compatibility for the Ditto drive
21.
Kansas City standard
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The Kansas City standard, or Byte standard, is a digital data format for audio cassette drives. Although the standard had existed from the earliest days of the microcomputer revolution, early microcomputers generally used punched tape for program storage, an expensive option. Computer consultant Jerry Ogdin conceived the use of tones on a cassette to replace the paper tapes. He took the idea to Les Solomon, editor of Popular Electronics magazine, in September 1975 the two co-authored an article on the HITS, using two tones to represent 1s and 0s. Soon after a number of manufacturers started using similar approaches, although each of these systems were incompatible, wayne Green, who had just started Byte magazine, wanted all the manufacturers to get together and produce a single cassette standard. The site picked was Kansas City, Missouri, the two-day meeting was attended by 18 people who settled on a system based on Don Lancasters design, published in Byte magazines first issue. After the meeting, Lee Felsenstein and Harold Mauch wrote the standard, a cassette interface is similar to a modem connected to a serial port. The 1s and 0s from the port are converted to audio tones using audio frequency-shift keying. A0 bit is represented as four cycles of a 1200 Hz sine wave, and this gives a data rate of 300 baud. Each frame starts with one start bit followed by eight data bits followed by two stop bits, so each frame is 11 bits, for a data rate of 27 3⁄11 bytes per second. The February 1976 issue of Byte had a report on the symposium, the 300 baud rate was reliable but slow. Most audio cassette circuits would support higher speeds, according to Solomon, the efforts were unsuccessful, Unfortunately, it didnt last long, before the month ended, everyone went back to his own tape standard and the recording confusion got worse. The participants of the Kansas City symposium include the following and they provided the S-100 bus CUTS Tape I/O interface board which offers both CUTS and Kansas City standard support to any S-100 system. Processor Technology provided an 8080 program to be recorded and this test record did not work and Processor Technology was unable to devote more time to the effort. Daniel Meyer and Gary Kay of Southwest Technical Products arranged for Robert Uiterwyk to provide his 4K BASIC interpreter program for the 6800 microprocessor, the idea was to record the program on audio tape in the Kansas City standard format and then make a master record from the tape. Eva-Tone made Soundsheets on thin vinyl that would hold one song and these were inexpensive and could be bound in a magazine. Bill Turner and Bill Blomgren of MicroComputerSystems Inc. along with Bob Jones of Interface Age and Bud Schamburger of Holiday Inn worked with EVA-TONE, the intermediate stage of recording to tape produced dropouts so a SWTPC AC-30 cassette interface was connected directly to the record cutting equipment. The May 1977 issue of Interface Age contains the first Floppy ROM, the September 1978 Floppy ROM Number 5 has two sides, Apple BASIC the automated dress pattern and IAPS format A program for writing letters
22.
Tarbell Cassette Interface
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The Tarbell Cassette Interface is an expansion card for use with the Altair 8800 early personal computer, or other systems using the Altairs S-100 bus. It was designed by Don Tarbell and sold by Tarbell Electronics as early as 1976, at the time, it was considered to be fast, reliable, and popular. While supporting the 1975 Kansas City standard, it introduced a much faster Tarbell standard which became a de facto standard for compact cassette data storage. Tarbell also sold products, including TARBELL CASSETTE BASIC in 1978. The latter includes a Tarbell floppy disk interface, said to plug into any S-100 bus computer, the Tarbell Cassette Interface Manual The board that launched the company and made Tarbell a household word in the world of the S-100 bus s100computers. com Tarbell S-100 boards and docs
23.
Commodore Datasette
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The Commodore 1530 Datasette was Commodores dedicated magnetic tape data storage device. Using compact cassettes as the medium, it provided inexpensive storage to Commodores 8-bit home/personal computers, notably the PET, VIC-20. A physically similar model, Commodore 1531, was made for the Commodore 16, unlike most microcomputer storage methods using compact cassettes, the Datasette uses a digital format. Instead of writing two tones to tape to indicate bits, patterns of waves are used including a parity bit. Programs are written twice to tape for error correction, if an error is detected when reading the first recording, the Datasette has built-in analog to digital converters and audio filters to convert the computers digital data into analog sound and vice versa. Connection to the computer is done via an edge connector or mini-DIN connector. The Datasette was more popular outside than inside the United States, in the United States disk drives quickly became standard, despite the Commodore 1541 floppy drive costing roughly five times as much as a Datasette. In most parts of Europe, the Datasette was the medium of choice for years after its launch. The inexpensive and widely available audio cassettes made the Datasette a good choice for the home computer mass market. The Datasette is slow—but because of its digital format extremely reliable—transferring data at around 50 bytes per second, after the Datasettes launch, however, special turbo tape software appeared, providing much faster tape operation. Such software was integrated into most commercial prerecorded applications, as well as being available separately for loading and saving the users homemade programs and these programs were only widely used in Europe, as the US market had long since moved onto disks. Datasettes can typically store about 100 kByte per 30 minute side, the use of turbo tape and other fast loaders increased this number to roughly 1000 kByte. The Datasette has only one cable with a PCB edge connector at the computer end. All input/output signals to the datasette are all digital and so all digital to analog, power is also included in this cable. The pinout is ground, +5 V DC, motor, read, write, the sense signal monitors the play, rewind, and fast-forward buttons, but cannot differentiate between them. A mechanical interlock prevented any two of them being pressed at the same time, unregulated 6.36 V DC is used to power the cassette motor. To record physical data, the zero-crossing from positive to negative voltage of the signal is measured. The resulting time between these positive to negative crossings is then compared to a threshold to determine whether the time since the last crossing is short or long, note the lower amplitude for the shorter periods
24.
Exatron Stringy Floppy
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The Exatron Stringy Floppy is a continuous loop tape drive developed by Exatron. The company introduced an S-100 stringy floppy drive at the 1978 West Coast Computer Faire, Exatron sold about 4,000 TRS-80 drives by August 1981 for $249.50 each, stating that it was our best seller by far. The tape cartridge is about the size of a business card, the magnetic tape inside the cartridge is 1⁄16 inch wide. There is no single catalog of files, to load a file the drive searches the entire tape. The tape loop only moves in one direction, so a file that starts behind the current location cannot be read until the drive searches the entire loop for it. In the July 1983 issue of Compute. s Gazette the Exatron Stringy Floppy for the Commodore VIC-20, calling the peripheral a viable alternative to tape or disk, the magazine noted that under ideal conditions, a Stringy Floppy can outperform a VIC-1540/1541 disk drive. Texas Instruments licensed the Stringy Floppy as the Waferdrive for its TI 99/2, Exatron pitched the ESF as The viable alternative. The ESF was faster and more reliable than a data cassette, cartridges, or wafers, were available with tape lengths ranging from 5 to 75 feet. Known data capacities/tape length are,4 kB/5 feet,16 kB/20 feet,48 kB/50 feet, one complete cycle through a 20-foot tape takes 55 to 65 seconds, depending on the number of files on it. ZX Microdrive Rotronics Wafadrive Exatron Stringy Floppy as described by Bill Fletcher Getting Files off Stringy Floppy Wafers for use in Emulators Advertisements Exatron Official Website
25.
ZX Microdrive
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The ZX Microdrive is a magnetic tape data storage system launched in July 1983 by Sinclair Research for its ZX Spectrum home computer. It was proposed as an alternative to the floppy disk. The Microdrive technology was also used in the Sinclair QL. The minimum storage capacity of a Microdrive tape cartridge was 85 KB and it is claimed the Microdrive was originally proposed by Andrew Grillet at an interview with Sinclair Research for what was to become the ZX81. Grillet proposed a version of the Learjet Stereo 8 system, modified to allow two 64k core images per track for roll-out roll-in swapping using the KUTS protocol, the ZX81 had only 1 kB of RAM. Grillet was offered better pay by Xerox Corporation, and never worked on the ZX81 or the Spectrum, the primary engineer involved in the development of the Microdrive was Ben Cheese. Typically of Sinclair Research, the ZX Microdrive was comparatively cheap and technologically innovative, connecting a ZX Microdrive to a ZX Spectrum required the ZX Interface 1 unit, costing £49.95, although this could be bought packaged with a Microdrive for £79.95. Later, in March 1985, the ZX Spectrum Expansion System was launched for £99.95, a total of eight ZX Microdrive units could be connected to the Interface 1 by daisy chaining one drive to the next via an electrical connector block. Microdrives used tiny cartridges containing a 5-metre endless loop of tape,1.9 mm wide, driven at 76 cm/second. The cartridges held a minimum of 85 kB when formatted on a ZX Microdrive, the data retrieval rate was 15 kB/s, i. e.120 kbit/s. It was possible to expand the capacity of a fresh microdrive cartridge by formatting it several times and this caused the tape to stretch slightly, increasing the length of the tape loop so that more sectors can be marked out on it. This procedure was documented in the Sinclair community magazines of the 1980s. Unfortunately, the system acquired a reputation for unreliability, the tapes stretched during use eventually rendering the data stored unreadable. Also the write protection was software-based so that a crash could erase the data on an entire tape in 8 seconds. Similar technology was used in devices, such as the Rotronics Wafadrive. Microdrives were also used as the storage medium of the Sinclair QL. These were very similar to the ZX Microdrive, but used a different logical format, the QL also included a Microdrive expansion bus allowing the attachment of up to six external QL Microdrives. These were never produced, probably due to lack of demand and it was however possible to connect ZX Microdrives to a QL by putting a twist in the cable
26.
Rotronics Wafadrive
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The Wafadrive comprised two continuous loop stringy floppy tape drives, an RS-232 interface and Centronics parallel port. The drives could run at two speeds, High speed and low speed, the cartridges, the same as those used in Entrepo stringy floppy devices for other microcomputers, were physically larger than Microdrive cartridges. They were available in three different capacities, nominally 16 kB,64 kB or 128 kB, the larger sizes had the disadvantage of slower access, due to the longer length of tape
27.
Digital Tape Format
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Digital Tape Format is a magnetic tape data storage format developed by Sony. It uses a 1/2 wide tape, in a cassette with two reels, which is written and read with a scan process. The format is described by the ECMA248 and ISO/IEC15731 standards, there are two sizes of tape cassettes, S and L. Notes, Both used ALDC compression DTF-2 used Fibre Channel or SCSI interfaces The tape cassettes are similar to those of Sony Betacam. Brochure for DTF-1 drive with specs DTF at the Computer Desktop Encyclopedia, including images
28.
Data8
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The 8 mm Backup Format is a magnetic tape data storage format used in computer systems, pioneered by Exabyte Corporation. It is also known as Data8, often abbreviated to D8 and is written as D-Eight on some Sony branded media, such systems can back up up to 40 GB of data depending on configuration. The tapes used are mechanically the same as the used in 8 mm video format recorders and camcorders. Until the advent of AIT, Exabyte were the sole vendor of 8 mm format tape drives, the company was formed with the aim of taking the 8 mm video format and making it suitable for data storage. They did so by building a reliable mechanism and data format used the common 8 mm video tape technology that was available then. This was the first form of helical scan tape used commercially for data storage, exabytes first 8 mm tape drive was made available in 1987. This was followed up with their Mammoth tape drive in 1996, exabytes drive mechanisms were frequently rebranded and integrated into UNIX systems. NOTE, The AIT and VXA formats and some less common formats also use 8 mm wide tape. Legend, RO - The tape drive can read this tape, Y - The tape drive can read and write this tape, but size is not known. Numbered entries indicate the native storage capacity for this combination of tape and these drives use Metal Particle tape. 1999—Mammoth-212 MB/s data transfer rate 4.6 cm/s tape speed during normal read/write operations 1, eCMA-169 ISO/IEC12246,1993, Specification of DA-1. ECMA-249 ISO/IEC15757, Specification of DA-2, eCMA-293 ISO/IEC18836, Specification of MammothTape-2
29.
Ecma International
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ECMA is a standards organization for information and communication systems. It acquired its current name in 1994, when the European Computer Manufacturers Association changed its name to reflect the global reach. As a consequence, the name is no longer considered an acronym, the organization was founded in 1961 to standardize computer systems in Europe. Ecma publications, including standards, can be copied by all interested parties without copyright restrictions. The development of standards and technical reports is done in co-operation with the national, European. Unlike national standardization bodies, Ecma is a membership-based organization and it takes pride in the resulting business-like approach to standards, claimed to lead to better standards in less time, thanks to a less bureaucratic process focused on achieving results by consensus. Ecma has actively contributed to worldwide standardization in information technology and telecommunications, more than 400 Ecma Standards and 100 Technical Reports have been published, more than 2/3 of which have also been adopted as international standards and/or technical reports. The memberlist of Ecma International is available on its website, thus, Ecma is not responsible for the standardization of Java. Ecma is involved in the standardization of the Ecma Office Open XML format based on the XML office document formats by Microsoft, the Ecma Office Open XML maintenance process is performed by technical committee 45
30.
Common Language Infrastructure
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This implies it is platform agnostic. The. NET Framework, Mono, DotGNU and Portable. NET are implementations of the CLI, among other things, the CLI specification describes the following four aspects, The Common Type System A set of data types and operations that are shared by all CTS-compliant programming languages. The Metadata Information about program structure is language-agnostic, so that it can be referenced between languages and tools, making it easy to work with code written in a language not using. The Common Language Specification A set of rules to which any language targeting the CLI should conform in order to interoperate with other CLS-compliant languages. The CLS rules define a subset of the Common Type System, the Virtual Execution System The VES loads and executes CLI-compatible programs, using the metadata to combine separately generated pieces of code at runtime. All compatible languages compile to Common Intermediate Language, which is a language that is abstracted from the platform hardware. When the code is executed, the platform-specific VES will compile the CIL to the language according to the specific hardware. In August 2000, Microsoft, Hewlett-Packard, Intel, and others worked to standardize CLI, by December 2001, it was ratified by the ECMA, with ISO standardization following in April 2003. Microsoft and its partners hold patents for CLI, ECMA and ISO require that all patents essential to implementation be made available under reasonable and non-discriminatory terms. It is common for RAND licensing to require some royalty payment, as of January 2013, neither Microsoft nor its partners have identified any patents essential to CLI implementations subject to RAND terms. To implement the CLI standard requires conformance to one of the supported and defined profiles of the standard, the kernel profile is actually a very small set of types to support in comparison to the well known core library of default. NET installations. However, the clause of the CLI allows for extending the supported profile by adding new methods and types to classes. But it does not allow for adding new members to interfaces, in 2012, ECMA and ISO published the new edition of the CLI standard, which is not covered by the Community Promise. NET Framework is Microsofts original commercial implementation of the CLI. Portable. NET, part of the project, is a free software implementation of ECMA-335 by Free Software Foundation. Standard Libraries List of CLI languages Standard ECMA-335, Common Language Infrastructure, ECMA C# and Common Language Infrastructure Standards
31.
Office Open XML
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Office Open XML is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents. The format was initially standardised by Ecma, and by the ISO, starting with Microsoft Office 2007, the Office Open XML file formats have become the default target file format of Microsoft Office. Microsoft Office 2010 provides read support for ECMA-376, read/write support for ISO/IEC29500 Transitional, Microsoft Office 2013 and Microsoft Office 2016 additionally support both reading and writing of ISO/IEC29500 Strict. In 2000, Microsoft released a version of an XML-based format for Microsoft Excel. In 2002, a new format for Microsoft Word followed. The Excel and Word formats—known as the Microsoft Office XML formats—were later incorporated into the 2003 release of Microsoft Office, Microsoft announced in November 2005 that it would co-sponsor standardization of the new version of their XML-based formats through Ecma International as Office Open XML. The presentation was made to Ecma by Microsofts Jean Paoli and Isabelle Valet-Harper, Microsoft submitted initial material to Ecma International Technical Committee TC45, where it was standardized to become ECMA-376, approved in December 2006. This standard was then fast-tracked in the Joint Technical Committee 1 of ISO, the resulting four-part International Standard was published in November 2008 and can be downloaded from the ITTF. A technically equivalent set of texts is published by Ecma as ECMA-376 Office Open XML File Formats — 2nd edition, the ISO standardization of Office Open XML was controversial and embittered, with much discussion both about the specification and about the standardization process. The same InfoWorld article reported that IBM threatened to leave standards bodies that it said allow dominant corporations like Microsoft to wield undue influence, richard Stallman of the Free Software Foundation has stated that Microsoft offers a gratis patent license for OOXML on terms which do not allow free implementations. Microsoft, the contributor to the standard, provided a covenant not to sue for its patent licensing. The covenant received a reception, with some like the Groklaw blog criticizing it. The Open Specification Promise was included in documents submitted to ISO/IEC in support of the ECMA-376 fast-track submission, Ecma International asserted that, The OSP enables both open source and commercial software to implement. The Office Open XML specification exists in a number of versions, the ECMA standard is structured in five parts to meet the needs of different audiences. Open Packaging Conventions The Open Packaging Conventions, for the package model and it defines core properties, thumbnails, digital signatures, and authorizations & encryption capabilities for parts or all of the contents in the package. XML schemas for the OPC are declared as XML Schema Definitions, markup Compatibility and Extensibility Describes extension facilities of OpenXML documents and specifies elements & attributes through which applications can operate across different extensions. Later versions of the ECMA-376 standard are aligned and technically equivalent to the corresponding ISO standard, Part 4 is to be read as a modification to Part 1, which it requires. A technically equivalent set of texts is published by Ecma as ECMA-376 2nd edition
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Open XML Paper Specification
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Open XML Paper Specification is an open specification for a page description language and a fixed-document format. Microsoft developed it as the XML Paper Specification, in June 2009, Ecma International adopted it as international standard ECMA-388. It is an XML-based specification, based on a new print path, in Windows 8. xps was replaced with the ECMA standard. oxps format which is not natively supported in older Windows versions. Notably, the language for XPS is a subset of XAML, allowing it to incorporate vector-graphic elements in documents. The elements used are described in terms of paths and other geometrical primitives, an XPS file is a ZIP archive using the Open Packaging Conventions, containing the files which make up the document. These include an XML markup file for each page, text, embedded fonts, raster images, 2D vector graphics, the contents of an XPS file can be examined by opening it in an application which supports ZIP files. There are two incompatible XPS formats on the market, the original document writer printed to. xps in Windows 7 and earlier. Beginning with Windows 8, the document writer defaults to the OpenXPS. oxps format, trying to open. oxps files in Windows 7 or lesser without a. oxps-to. xps converter will result in an error. XpsConverter converts documents between. xps and. oxps format, while OxpsConverter converts documents from. oxps to. xps format, XPS specifies a set of document layout functionality for paged, printable documents. It also has support for such as color gradients, transparencies, CMYK color spaces, printer calibration, multiple-ink systems. XPS supports the Windows Color System color management technology for color conversion precision across devices and it includes a software raster image processor. The print subsystem supports named colors, simplifying color definition for images transmitted to printers supporting those colors, XPS supports HD Photo images natively for raster images. Like Adobe Systemss PDF format, XPS is a document format designed to preserve document fidelity. PDF is a database of objects that may be created from PostScript or generated directly from applications, both formats are compressed, albeit using different methods. The filter pipeline architecture of XPS is also similar to the one used in supporting the PostScript page description language. PDF includes dynamic capabilities purposely not supported by the XPS format, XPS is supported on several versions of Windows. Because the printing architecture of Windows Vista uses XPS as the spooler format, XPS documents can be created by printing to the virtual XPS printer driver. The XPS Viewer is installed by default in Windows Vista, Windows 7, the viewer is hosted within Internet Explorer in Windows Vista, but is a native application in 7 and 8 which supports digital signatures
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Holographic Versatile Disc
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The Holographic Versatile Disc is an optical disc technology developed between April 2004 and mid-2008 that can store up to several terabytes of data on an optical disc 10 cm or 12 cm in diameter. The reduced radius reduces cost and materials used and it employs a technique known as collinear holography, whereby a green and red laser beam are collimated in a single beam. The green laser reads data encoded as laser interference fringes from a layer near the top of the disc. A red laser is used as the beam to read servoinformation from a regular CD-style aluminium layer near the bottom. Servoinformation is used to monitor the position of the head over the disc, similar to the head, track. On a CD or DVD this servoinformation is interspersed among the data, a dichroic mirror layer between the holographic data and the servo data reflects the green laser while letting the red laser pass through. Standards for 100 GB read-only holographic discs and 200 GB recordable cartridges were published by ECMA in 2007, a number of release dates were announced, all since passed. High densities are possible by moving these closer on the tracks,100 GB at 18 μm separation,200 GB at 13 μm,500 GB at 8 μm, and most demonstrated of 5 TB for 3 μm on a 10 cm disc. The system uses a laser, with an output power of 1 watt which is high power for a consumer device laser. Possible solutions include improving the sensitivity of the used, or developing and commoditizing a laser capable of higher power output while being suitable for a consumer unit. HVD is not the technology in high-capacity, optical storage media. Such large optical storage capacities compete favorably with the Blu-ray Disc format, however, holographic drives are projected to initially cost around US$15,000, and a single disc around US$120–180, although prices are expected to fall steadily. Since InPhase Technologies were unable to deliver their product, they ran out of funds. The Holography System Development Forum is a coalition of corporations purposed to provide a forum for testing and technical discussion of all aspects of HVD design. As of March 2012, the companies are members of the forum. Kyoeisha Pulstec Shibaura Mechatronics Corporation Oracle Corporation Teijin Chemicals Ltd, on June 11,2007, TC44 published the first two HVD standards, ECMA-377, defining a 200 GB HVD recordable cartridge and ECMA-378, defining a 100 GB HVD-ROM disc. Its next stated goals are 30 GB HVD cards and submission of these standards to the International Organization for Standardization for ISO approval.6 TB media available in 2010, InPhase, a now bankrupt, company that developed a competing holographic storage format. Video explaining holographic storage – PC Magazine, October 4,2006 Holography system rides single beam EE Times, February 27,2006 – interview with Hideyoshi Horimai and Yoshio Aoki of Optware Corp
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CD-ROM
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A CD-ROM /ˌsiːˌdiːˈrɒm/ is a pre-pressed optical compact disc which contains data. The name is an acronym which stands for Compact Disc Read-Only Memory, computers can read CD-ROMs, but cannot write to CD-ROMs which are not writable or erasable. From the mid-1990s until the mid-2000s, CD-ROMs were popularly used to distribute software for computers, some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer. An early CD-ROM format was developed by Sony and Denon, introduced at a Japanese computer show in 1984 and it was an extension of Compact Disc Digital Audio, and adapted the format to hold any form of digital data, with a capacity of 540 MiB. The Yellow Book is the standard that defines the format of CD-ROMs. One of a set of books that contain the technical specifications for all CD formats. CD-ROMs are identical in appearance to audio CDs, and data are stored and retrieved in a similar manner. Discs are made from a 1.2 mm thick disc of polycarbonate plastic, data is stored on the disc as a series of microscopic indentations. A laser is shone onto the surface of the disc to read the pattern of pits. This pattern of changing intensity of the beam is converted into binary data. Several formats are used for data stored on discs, known as the Rainbow Books. The Yellow Book, published in 1988, defines the specifications for CD-ROMs, the CD-ROM standard builds on top of the original Red Book CD-DA standard for CD audio. Other standards, such as the White Book for Video CDs, the Yellow Book itself is not freely available, but the standards with the corresponding content can be downloaded for free from ISO or ECMA. There are several standards that define how to structure data files on a CD-ROM, ISO9660 defines the standard file system for a CD-ROM. ISO13490 is an improvement on this standard which adds support for non-sequential write-once and re-writeable discs such as CD-R and CD-RW, as well as multiple sessions. The ISO13346 standard was designed to address most of the shortcomings of ISO9660, and a subset of it evolved into the UDF format, which was adopted for DVDs. The bootable CD specification was issued in January 1995, to make a CD emulate a hard disk or floppy disk, is called El Torito, data stored on CD-ROMs follows the standard CD data encoding techniques described in the Red Book specification. This includes cross-interleaved Reed–Solomon coding, eight-to-fourteen modulation, and the use of pits, the structures used to group data on a CD-ROM are also derived from the Red Book
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ISO 9660
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ISO9660 is a file system standard published by the International Organization for Standardization for optical disc media. It aims at supporting different computer operating systems such as Windows, classic Mac OS, ISO9660 traces its roots to the High Sierra Format file system. High Sierra arranged file information in a dense, sequential layout to minimize access by using a hierarchical tree file system arrangement, similar to UNIX. High Sierra was adopted in December 1986 as a standard by Ecma International as ECMA-119 and submitted for fast tracking to the ISO. The following is the overall structure of the ISO9660 file system, The System Area. For example, a CD-ROM may contain a file system descriptor in this area. The data area begins with a set of one or more volume descriptors, collectively the volume descriptor set acts as a header for the data area, describing its content. The volume descriptor set terminator is simply a type of volume descriptor with the purpose of marking the end of this set of structures. Each volume descriptor is 2048 bytes in size, fitting perfectly into a single Mode 1 or Mode 2 Form 1 sector and they have the following structure, The data field of a volume descriptor may be subdivided into several fields, with the exact content depending on the type. The Primary Volume Descriptor provides information about the volume, characteristics and metadata, other fields contain the description or name of the volume, and information about who created it and with which application. The size of the blocks which the file system uses to segment the volume is also stored in a field inside the primary volume descriptor. In addition to the Primary Volume Descriptor, Supplementary Volume Descriptors or Enhanced Volume Descriptors may be present. The standard specifies that ISO2022 is used for managing code sets that are wider than 8 bytes, consequently, ISO9660 supports international single-byte and multi-byte character sets, provided they fit into the framework of the referenced standards. Enhanced Volume Descriptors were introduced in ISO9660, Amendment 1 and they relax some of the requirements of the other volume descriptors and the directory records referenced by them, for example, the directory depth can exceed eight, file identifiers need not contain. Or file version number, the length of a file and directory identifier is maximized to 207, redundant copies of each volume descriptor can also be included in case the first copy of the descriptor becomes corrupt. Directory entries are stored following the location of the directory entry. Both directories and files are stored as extents, which are series of sectors. Files and directories are differentiated only by an attribute that indicates its nature
