Computer memory

In computing, memory refers to a device, used to store information for immediate use in a computer or related computer hardware device. It refers to semiconductor memory metal–oxide–semiconductor memory, where data is stored within MOS memory cells on a silicon integrated circuit chip; the term "memory" is synonymous with the term "primary storage". Computer memory operates at a high speed, for example random-access memory, as a distinction from storage that provides slow-to-access information but offers higher capacities. If needed, contents of the computer memory can be transferred to secondary storage. An archaic synonym for memory is store; the term "memory", meaning "primary storage" or "main memory", is associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based MOS transistors, used for example as primary storage but other purposes in computers and other digital electronic devices. There are two main kinds of semiconductor memory and non-volatile.

Examples of non-volatile memory are ROM, PROM, EPROM and EEPROM memory. Examples of volatile memory are primary storage, dynamic random-access memory, fast CPU cache memory, static random-access memory, fast but energy-consuming, offering lower memory areal density than DRAM. Most semiconductor memory is organized into memory cells or bistable flip-flops, each storing one bit. Flash memory organization includes multiple bits per cell; the memory cells are grouped into words of fixed word length, for example 1, 2, 4, 8, 16, 32, 64 or 128 bit. Each word can be accessed by a binary address of N bit, making it possible to store 2 raised by N words in the memory; this implies that processor registers are not considered as memory, since they only store one word and do not include an addressing mechanism. Typical secondary storage devices are solid-state drives. In the early 1940s, memory technology permitted a capacity of a few bytes; the first electronic programmable digital computer, the ENIAC, using thousands of octal-base radio vacuum tubes, could perform simple calculations involving 20 numbers of ten decimal digits which were held in the vacuum tube accumulators.

The next significant advance in computer memory came with acoustic delay line memory, developed by J. Presper Eckert in the early 1940s. Through the construction of a glass tube filled with mercury and plugged at each end with a quartz crystal, delay lines could store bits of information in the form of sound waves propagating through mercury, with the quartz crystals acting as transducers to read and write bits. Delay line memory would be limited to a capacity of up to a few hundred thousand bits to remain efficient. Two alternatives to the delay line, the Williams tube and Selectron tube, originated in 1946, both using electron beams in glass tubes as means of storage. Using cathode ray tubes, Fred Williams would invent the Williams tube, which would be the first random-access computer memory; the Williams tube would prove less expensive. The Williams tube would prove to be frustratingly sensitive to environmental disturbances. Efforts began in the late 1940s to find non-volatile memory. Magnetic-core memory allowed for recall of memory after power loss.

It was developed by Frederick W. Viehe and An Wang in the late 1940s, improved by Jay Forrester and Jan A. Rajchman in the early 1950s, before being commercialised with the Whirlwind computer in 1953. Magnetic-core memory would become the dominant form of memory until the development of MOS semiconductor memory in the 1960s. Semiconductor memory began in the early 1960s with bipolar memory. Bipolar semiconductor memory made from discrete devices was first shipped by Texas Instruments to the United States Air Force in 1961; the same year, the concept of solid-state memory on an integrated circuit chip was proposed by applications engineer Bob Norman at Fairchild Semiconductor. The first bipolar semiconductor memory IC chip was the SP95 introduced by IBM in 1965. While bipolar memory offered improved performance over magnetic-core memory, it could not compete with the lower price of magnetic-core, which remained dominant up until the late 1960s. Bipolar memory failed to replace magnetic-core memory because bipolar flip-flop circuits were too large and expensive.

The invention of the MOSFET, by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959, enabled the practical use of metal–oxide–semiconductor transistors as memory cell storage elements, a function served by magnetic cores. MOS memory was developed by John Schmidt at Fairchild Semiconductor in 1964. In addition to higher performance, MOS semiconductor memory was cheaper and consumed less power than magnetic core memory. In 1965, J. Wood and R. Ball of the Royal Radar Establishment proposed digital storage systems that use CMOS memory cells, in addition to MOSFET power devices for the power supply, switched cross-coupling and delay line storage; the development of silicon-gate MOS integrated circuit technology by Federico Faggin at Fairchild in 1968 enabled the production of MOS memory chips. NMOS memory was commercialized by IBM in the early 1970s. MOS memory overtook magnetic core memory as the dom

Bruce & Morgan

Bruce & Morgan was an architectural firm in Georgia. It was a partnership during 1882 to 1904 of Alexander Bruce and Thomas Henry Morgan NRHP-listed Brooks County Courthouse, Courthouse Sq. Quitman, GA NRHP-listed Bulloch County Courthouse, 1894, Courthouse Sq. Statesboro, GA NRHP-listed Butts County Courthouse, Courthouse Sq. Jackson, GA NRHP-listed J. R. Carmichael House, 149 McConough Rd. Jackson, GA NRHP-listed Central of Georgia Railroad Terminal, 1200 6th Ave. Columbus, GA NRHP-listed Fayette County Courthouse, GA 85, Fayetteville, GA NRHP-listed Fire Station No. 6, 39 Boulevard NE, Atlanta, GA Martin Luther King, Jr. NHL District contributing structure. Floyd County Courthouse, 5th Ave. and Tribune St. Rome, GA NRHP-listed Georgia Institute of Technology Administration Building, 225 North Avenue NW, Atlanta, GA NRHP-listed Monroe County Courthouse, Courthouse Sq. Forsyth, GA NRHP-listed Newton County Courthouse, Courthouse Sq. Covington, GA NRHP-listed Oakland Cemetery, 248 Oakland Ave. SE, Atlanta, GA NRHP-listed Paulding County Courthouse, Courthouse Sq.

Dallas, GA NRHP-listed M. Rich and Brothers and Company Building at 82 Peachtree St. SE, Atlanta, GA Talbot County Courthouse, Courthouse Sq. Talbotton, GA NRHP-listed Walton County Courthouse, Courthouse Sq. Monroe, GA NRHP-listed Wigwam Hotel One or more works in Clemson University Historic District I, northern portion of campus along US 76, Clemson, SC NRHP-listed One or more works in Covington Historic District, Roughly Covington City S of US 278, Covington, GA NRHP-listed One or more works in Hotel Row Historic District, 205—235 Mitchell St. Atlanta, GA NRHP-listed One or more works in Monroe Commercial Historic District and Broad Sts. Monroe, GA NRHP-listed One or more works in Winthrop College Historic District, along Oakland Ave. between Cherry Rd. and Stewart Ave. on the Winthrop College campus, Rock Hill, South Carolina NRHP-listed St. Nicholas Hotel, 141 Flint Ave. 300—310 Washington St. Albany, GA NRHP-listed

Awami Tahreek

Sindhi Awami Tahreek or now Awami Tahreek, Pakistan, is a left-wing, pro-social democratic, pro-socialist, progressive political party based in Sindh, headquartered in Hyderabad, Pakistan. Awami Tahreek was formed on March 5, 1970, by the leading writers, intellectuals in Hyderabad, Sindh. At the first party meeting, the leading theoretician Rasool Bux Palijo was elected as its first general secretary, it has evolved into a national party and supported the anti-feudal elements against the PPP-P and PML-N in Sindh and Western Punjab. Awami Tahreek has supported movements including: Neelam Band Karyo Movement Sindhi Voter Lists Movement MRD Journalist Movement Anti-Urban Terrorism Movement and Anti-Kalabagh Dam and Thal Canal MovementRecently, AT has started to create local/regional offices in other provinces, has broadened its political philosophy from a provincial to a national level. Awami Tahreek is a political party devoted to non-violence in its democratic struggle to attain freedom of the people through the scientific and revolutionary tenets of Marxism-Leninism-Maoism.

It is committed to people's democracy and social justice, establishment of a welfare state in a country where people can have equity, political freedom, economic opportunity, genuine provincial autonomy. Its platform is that a comprehensive overhauling of society is required in order to deliver the benefits of a welfare state to the masses. Awami Tahreek stands for equal rights for all citizens without distinction of sex, color, faith, or creed. Awami Tahreek is strict in opposing capitalism, army rule, terrorism, racism, gender discrimination, religious bigotry. AT promises the replacement of feudalism with principles of socialism to protect and advance the interests of peasantry. AT continues to champion the cause of the unity of Pakistan in general and Sindh in particular, the caste system, communities and ethnic groups. Since the foundation of the party, it has come forward as a builder of Muslim-Hindu-Christian unity. Awami Tahreek opposed the division of Sindh. Sindhi Shagird Tahreek Fazil Rahu Sindhiani Tahreek Hyder Bux Jatoi Sindh Hari Committee Zarina Baloch Official webpage