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Perpendicular Magnetic Recording
Perpendicular recording (or perpendicular magnetic recording, PMR), also known as conventional magnetic recording (CMR), is a technology for data recording on magnetic media, particularly hard disks. It was first proven advantageous in 1976 by Shun-ichi Iwasaki, then professor of the Tohoku University in Japan, and first commercially implemented in 2005. The first industry-standard demonstration showing unprecedented advantage of PMR over longitudinal magnetic recording (LMR) at nanoscale dimensions was made in 1998 at IBM Almaden Research Center in collaboration with researchers of Data Storage Systems Center (DSSC) – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU). Advantages Perpendicular recording can deliver more than three times the Computer storage density, storage density of traditional longitudinal recording. In 1986, Maxell announced a floppy disk using perpendicular recording that could store . Perpendicular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Media
Magnetic storage or magnetic recording is the storage of data on a magnetized medium. Magnetic storage uses different patterns of magnetisation in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads. Magnetic storage media, primarily hard disks, are widely used to store computer data as well as audio and video signals. In the field of computing, the term ''magnetic storage'' is preferred and in the field of audio and video production, the term ''magnetic recording'' is more commonly used. The distinction is less technical and more a matter of preference. Other examples of magnetic storage media include floppy disks, magnetic tape, and magnetic stripes on credit cards. History Magnetic storage in the form of wire recording—audio recording on a wire—was publicized by Oberlin Smith in the Sept 8, 1888 issue of ''Electrical World''. Smith had previously filed a patent in September, 1878 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coercivity
Coercivity, also called the magnetic coercivity, coercive field or coercive force, is a measure of the ability of a ferromagnetic material to withstand an external magnetic field without becoming Magnetization, demagnetized. Coercivity is usually measured in oersted or ampere/meter units and is denoted . An analogous property in electrical engineering and materials science, electric coercivity, is the ability of a ferroelectric material to withstand an external electric field without becoming polarization density, depolarized. Ferromagnetic materials with high coercivity are called magnetically ''hard'', and are used to make permanent magnets. Materials with low coercivity are said to be magnetically ''soft''. The latter are used in transformer and inductor magnetic core, cores, recording heads, microwave devices, and magnetic shielding. Definitions Coercivity in a ferromagnet, ferromagnetic material is the intensity of the applied magnetic field (''H'' field) required ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exchange Spring Media
Exchange spring media (also exchange coupled composite media or ECC) is a magnetic storage technology for hard disk drives that allows to increase the storage density in magnetic recording. The idea, proposed in 2004 by Suess et al., is that the recording media consists of exchange coupled soft and hard magnetic layers. Exchange spring media allows a good writability due to the write-assist nature of the soft layer. Hence, hard magnetic layers such as FePt, CoCrPt-alloys or hard magnetic multilayer structures can be written with conventional write heads. Due to the high anisotropy these grains are thermally stable even for small grain sizes. Small grain sizes are required for high density recording. The introduction of the soft layer does not decrease the thermal stability of the entire structure if the hard layer is sufficiently thick. The required thickness of the hard layer for best thermal stability is the exchange length of the hard layer material. The first experimental realiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial ATA
SATA (Serial AT Attachment) is a computer bus interface that connects host adapter, host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. Serial ATA succeeded the earlier Parallel ATA (PATA) standard to become the predominant interface for storage devices. Serial ATA industry compatibility specifications originate from the Serial ATA International Organization (SATA-IO) which are then released by the INCITS Technical Committee T13, AT Attachment (INCITS T13). History SATA was announced in 2000 in order to provide several advantages over the earlier PATA interface such as reduced cable size and cost (seven conductors instead of 40 or 80), native hot swapping, faster data transfer through higher signaling rates, and more efficient transfer through an (optional) I/O queuing protocol. #1.0, Revision 1.0 of the specification was released in January 2003. Serial ATA industry compatibility specifications originate from the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital
Western Digital Corporation is an American data storage company headquartered in San Jose, California. Established in 1970, the company is one of the world's largest manufacturers of hard disk drives (HDDs). History 1970s Western Digital was founded on April 23, 1970, by Alvin B. Phillips, a Motorola employee, as General Digital Corporation, initially a manufacturer of MOS test equipment. It was originally based in Newport Beach, California, shortly thereafter moving to Santa Ana, California, and would go on to become one of the largest technology firms headquartered in Orange County. It rapidly became a specialty semiconductor maker, with start-up capital provided by several individual investors and industrial giant Emerson Electric. Around July 1971, it adopted its current name and soon introduced its first product, the ''WD1402A'' UART. During the early 1970s, the company focused on making and selling calculator chips, and by 1975, Western Digital was the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toshiba
is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors, hard disk drives, printers, batteries, lighting, as well as IT solutions such as quantum cryptography. It was formerly also one of the biggest manufacturers of personal computers, consumer electronics, home appliances, and medical equipment. The Toshiba name is derived from its former name, Tokyo Shibaura Denki K.K. which in turn was a 1939 merger between Shibaura Seisaku-sho (founded in 1875) and Tokyo Denki (founded in 1890). The company name was officially changed to Toshiba Corporation in 1978. A technology company with a long history and sprawling businesses, Toshiba is a household name in Japan and has long been viewed as a symbol of the country's technological prowess post-World War II. As a semiconductor company and the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdrive
The Microdrive was a miniature, 1-inch hard disk drive released in 1998 by IBM. The idea was originally created in 1992 by duTimothy J. RileyanThomas R. Albrechtat the Almaden Research Center in San Jose. A team of engineers and designers at IBM's Fujisawa, Japan facility helped make the creation of the drive possible. Due to the failure of the Kittyhawk, a 1.3-inch hard disk drive also created in 1992 by Hewlett Packard, initial support for it was reluctant. Despite that, development persisted. The Microdrive caused the creation of and used the CompactFlash Type II format which became the ''de facto'' standard for devices utilizing the technology at the time. Because of this, and its advantages over flash technology, the Microdrive ended up being a success. Although a niche for a short time, the Microdrive market later became very competitive. Many companies began producing miniature hard disk drives also referred to as Microdrives. Some offered more storage capacity or w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitachi, Ltd
() is a Japanese multinational conglomerate founded in 1910 and headquartered in Chiyoda, Tokyo. The company is active in various industries, including digital systems, power and renewable energy, railway systems, healthcare products, and financial systems. The company was founded as an electrical machinery manufacturing subsidiary of the Kuhara Mining Plant in Hitachi, Ibaraki by engineer Namihei Odaira in 1910. It began operating as an independent company under its current name in 1920. Hitachi is listed on the Tokyo Stock Exchange and is a key component of the Nikkei 225 and TOPIX Core30 indices. As of June 2024, it has a market capitalisation of 16.9 trillion yen, making it the fourth largest Japanese company by market value. In terms of global recognition, Hitachi was ranked 38th in the 2012 Fortune Global 500 and 129th in the 2012 Forbes Global 2000. Hitachi is a highly globalised conglomerate. In the fiscal year 2023, it generated approximately 61% of its total revenu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megabyte Per Second
In telecommunications, data transfer rate is the average number of bits (bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s ( megabyte per second), or about 0.1192 MiB/s ( mebibyte per second). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Signaling Rate
In telecommunications, data signaling rate (DSR), also known as gross bit rate, is the aggregate rate at which data passes a point in the transmission (telecommunications), transmission data link, path of a data transmission system. Properties # The DSR is usually expressed in bits per second. # The data signal (information theory), signaling rate is given by \sum_^ \frac where ''m'' is the number of parallel channels, ''ni'' is the number of significant conditions of the modulation in the ''i''-th Communication channel, channel, and ''Ti'' is the unit interval (data transmission), unit interval, expressed in seconds, for the ''i''-th channel. # For serial transmission in a single channel, the DSR reduces to (1/''T'')log2''n''; with a two-condition modulation, i. e. ''n'' = 2, the DSR is 1/''T'', according to Hartley's law. # For parallel transmission with equal unit intervals and equal numbers of significant conditions on each channel, the DSR is (''m''/''T'')log2''n''; in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagate Technology
Seagate Technology Holdings plc is an American Computer data storage, data storage company. It was incorporated in 1978 as Shugart Technology and commenced business in 1979. Since 2010, the company has been incorporated in Dublin, Ireland, with operational headquarters in Fremont, California, United States. Seagate developed the first 5.25-inch hard disk drive (HDD), the 5-megabyte ST-506, in 1980. They were a major supplier in the microcomputer market during the 1980s, especially after the introduction of the IBM XT in 1983. Much of their growth has come through their acquisition of competitors. In 1989, Seagate acquired Control Data Corporation's Imprimis division, the makers of CDC's HDD products. Seagate acquired Conner Peripherals in 1996, Maxtor in 2006, and Samsung Electronics, Samsung's HDD business in 2011. Today, Seagate, along with its competitor Western Digital, dominates the HDD market. History Founding as Shugart Technology Seagate Technology (then called S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
