|
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 oData 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 storage density of traditional longitudinal recording. In 1986, Maxell announced a floppy disk using perpendicular recording that could store . Perpendicular recording was later used ... [...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] |
Superparamagnetic Limit
Superparamagnetism is a form of magnetism which appears in small ferromagnetic or ferrimagnetic nanoparticles. In sufficiently small nanoparticles, magnetization can randomly flip direction under the influence of temperature. The typical time between two flips is called the Néel relaxation time. In the absence of an external magnetic field, when the time used to measure the magnetization of the nanoparticles is much longer than the Néel relaxation time, their magnetization appears to be in average zero; they are said to be in the superparamagnetic state. In this state, an external magnetic field is able to magnetize the nanoparticles, similarly to a paramagnet. However, their magnetic susceptibility is much larger than that of paramagnets. The Néel relaxation in the absence of magnetic field Normally, any ferromagnetic or ferrimagnetic material undergoes a transition to a paramagnetic state above its Curie temperature. Superparamagnetism is different from this standard transi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shingled Magnetic Recording
Shingled magnetic recording (SMR) is a magnetic storage data recording technology used in hard disk drives (HDDs) to increase storage density and overall per-drive storage capacity. Conventional hard disk drives record data by writing non-overlapping magnetic tracks parallel to each other (perpendicular magnetic recording, PMR), while shingled recording writes new tracks that overlap part of the previously written magnetic track, leaving the previous track narrower and allowing for higher track density. Thus, the tracks partially overlap similar to roof shingles. This approach was selected because, if the writing head is made too narrow, it cannot provide the very high fields required in the recording layer of the disk. The overlapping-tracks architecture complicates the writing process since writing to one track also overwrites an adjacent track. If adjacent tracks contain valid data, they must be rewritten as well. As a result, SMR drives are divided into many append-only (seq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial ATA
SATA (Serial AT Attachment) is a computer bus interface that connects 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 promulgated 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. Revision 1.0 of the specification was released in January 2003. Serial ATA industry compatibility specifications originate from the Serial ATA Internat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fujitsu
is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the largest in Japan, in 2021. The hardware offerings from Fujitsu are mainly of personal and enterprise computing products, including x86, SPARC and mainframe compatible server products, although the corporation and its subsidiaries also offer a diversity of products and services in the areas of data storage, telecommunications, advanced microelectronics, and air conditioning. It has approximately 126,400 employees and its products and services are available in approximately 180 countries. Fujitsu is listed on the Tokyo Stock Exchange and Nagoya Stock Exchange; its Tokyo listing is a constituent of the Nikkei 225 and TOPIX 100 indices. History 1935 to 2000 Fujitsu was established on June 20, 1935, which makes it one of the oldest operating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital
Western Digital Corporation (WDC, commonly known as Western Digital or WD) is an American computer drive manufacturer and data storage company, headquartered in San Jose, California. It designs, manufactures and sells data technology products, including data storage devices, data center systems and cloud storage service A file-hosting service, cloud-storage service, online file-storage provider, or cyberlocker is an internet hosting service specifically designed to host user files. It allows users to upload files that could be accessed over the internet afte ...s. Western Digital has a long history in the electronics industry as an integrated circuit maker and a storage products company. It is one of the largest computer hard disk drive manufacturers, along with producing solid state drives and flash memory devices. Its competitors include the data management and storage companies Seagate Technology and Micron Technology. History 1970s Western Digital was founded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors, hard disk drives (HDD), printers, batteries, lighting, as well as IT solutions such as quantum cryptography which has been in development at Cambridge Research Laboratory, Toshiba Europe, located in the United Kingdom, now being commercialised. It was one of the biggest manufacturers of personal computers, consumer electronics, home appliances, and medical equipment. As a semiconductor company and the inventor of flash memory, Toshiba had been one of the top 10 in the chip industry until its flash memory unit was spun off as Toshiba Memory, later Kioxia, in the late 2010s. The Toshiba name is derived from its former name, Tokyo Shibaura Denki K.K. (Tokyo Shibaura Elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdrive
The Microdrive is a registered trademark for miniature, 1-inch hard disks produced by IBM and Hitachi. These rotational media storage devices were designed to fit in CompactFlash (CF) Type II slots. The release of similar drives by other makers led to them often being referred to as "microdrives" too. By 2010, Microdrives were viewed as obsolete, having been overtaken by solid-state flash media in read/write performance, storage capacity, durability, and price. History Prior to the 1-inch Microdrive, a 1.3-inch HDD nicknamed the " Kittyhawk" was developed and launched in June 1992 by Hewlett Packard with a capacity of 20, then later 40 MB. These units weighed about 28 g (1 oz), with dimensions of 2.0" × 1.44" × 0.414" (50.8mm × 36.5mm × 10.5mm) and were the physically smallest hard drives in the world before the Microdrive. The Kittyhawk was a failure however, and didn't last long in the market. Development The idea of the Microdrive was created by IBM researcheTi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hitachi, Ltd
() is a Japanese multinational corporation, multinational Conglomerate (company), conglomerate corporation headquartered in Chiyoda, Tokyo, Japan. It is the parent company of the Hitachi Group (''Hitachi Gurūpu'') and had formed part of the Nissan Group, Nissan ''zaibatsu'' and later DKB Group and Fuyo Group of companies before DKB and Fuji Bank (the core Fuyo Group company) merged into the Mizuho Financial Group. As of 2020, Hitachi conducts business ranging from Information technology, IT, including Artificial intelligence, AI, the Internet of things, Internet of Things, and big data, to infrastructure. Hitachi is listed on the Tokyo Stock Exchange and Nagoya Stock Exchange and its Tokyo listing is a constituent of the Nikkei 225 and TOPIX Core30 indices. It is ranked 38th in the 2012 Fortune Global 500 and 129th in the 2012 Forbes Global 2000. History Hitachi was founded in 1910 by electrical engineer Namihei Odaira (1874–1951) in Ibaraki Prefecture. The company's firs ... [...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 Instit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Signaling Rate
In telecommunication, data signaling rate (DSR), also known as gross bit rate, is the aggregate rate at which data passes a point in the transmission path of a data transmission system. # The DSR is usually expressed in bits per second. # The data 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 channel, and ''Ti'' is the 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 case of a two-condition modulation, this reduces to ''m''/''T''. # The DSR may be expressed in bauds, in which case, the factor log2''ni'' in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seagate Technology
Seagate Technology Holdings plc is an American 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'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 Shugart Technology) was incorporated on No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
