Magnetic tape

Magnetic tape is a medium for magnetic recording, made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders respectively. A device that stores computer data on magnetic tape is known as a tape drive. Magnetic tape revolutionized reproduction and broadcasting, it allowed radio, which had always been broadcast live, to be recorded for or repeated airing. It allowed gramophone records to be recorded in multiple parts, which were mixed and edited with tolerable loss in quality, it was a key technology in early computer development, allowing unparalleled amounts of data to be mechanically created, stored for long periods, accessed. In recent decades, other technologies have been developed that can perform the functions of magnetic tape. In many cases, these technologies have replaced tape. Despite this, innovation in the technology continues, Sony and IBM continue to produce new magnetic tape drives.

Over time, magnetic tape made in the 1970s and 1980s can suffer from a type of deterioration called sticky-shed syndrome. It can render the tape unusable; the oxide side of a tape is the surface. This is the side that stores the information, the opposite side is a substrate to give the tape strength and flexibility; the name originates from the fact that the magnetic side of most tapes is made of iron oxide, though chromium is used for some tapes. An adhesive binder between the oxide and the substrate holds the two sides together. In all tape formats, a tape drive uses motors to wind the tape from one reel to another, passing over tape heads to read, write or erase as it moves. Magnetic tape was invented for recording sound by Fritz Pfleumer in 1928 in Germany, based on the invention of magnetic wire recording by Oberlin Smith in 1888 and Valdemar Poulsen in 1898. Pfleumer's invention used a ferric oxide powder coating on a long strip of paper; this invention was further developed by the German electronics company AEG, which manufactured the recording machines and BASF, which manufactured the tape.

In 1933, working for AEG, Eduard Schuller developed the ring-shaped tape head. Previous head designs were tended to shred the tape. Another important discovery made in this period was the technique of AC biasing, which improved the fidelity of the recorded audio signal by increasing the effective linearity of the recording medium. Due to the escalating political tensions, the outbreak of World War II, these developments in Germany were kept secret. Although the Allies knew from their monitoring of Nazi radio broadcasts that the Germans had some new form of recording technology, its nature was not discovered until the Allies acquired German recording equipment as they invaded Europe at the end of the war, it was only after the war that Americans Jack Mullin, John Herbert Orr, Richard H. Ranger, were able to bring this technology out of Germany and develop it into commercially viable formats. Bing Crosby, an early adopter of the technology, made a large investment in the tape hardware manufacturer Ampex.

A wide variety of audio tape recorders and formats have been developed since, most reel-to-reel and Compact Cassette. Digital recording to flash memory and hard disk has supplanted magnetic tape for most purposes; however tape as a verb and as a noun has remained the common parlance for the recording process. The practice of recording and editing audio using magnetic tape established itself as an obvious improvement over previous methods. Many saw the potential of making the same improvements in recording the video signals used by television. Video signals use more bandwidth than audio signals. Existing audio tape recorders could not capture a video signal. Many set to work on resolving this problem. Jack Mullin and the BBC both created crude working systems that involved moving the tape across a fixed tape head at high speeds. Neither system saw much use, it was the team at Ampex, led by Charles Ginsburg, that made the breakthrough of using a spinning recording head and normal tape speeds to achieve a high head-to-tape speed that could record and reproduce the high bandwidth signals of video.

The Ampex system was called Quadruplex and used 2-inch-wide tape, mounted on reels like audio tape, which wrote the signal in what is now called transverse scan. Improvements by other companies Sony, led to the development of helical scan and the enclosure of the tape reels in an easy-to-handle videocassette cartridge. Nearly all modern videotape systems use helical cartridges. Videocassette recorders used to be common in homes and television production facilities, but many functions of the VCR have been replaced with more modern technology. Since the advent of digital video and computerized video processing, optical disc media and digital video recorders can now perform the same role as videotape; these devices offer improvements like random access to any scene in the recording and the ability to pause a live program and have replaced videotape in many situations. Magnetic tape was first used to record computer data in 1951 on the Eckert-Mauchly UNIVAC I; the system's UNISERVO I tape drive used a thin strip of one half inch wide metal, consisting of nickel-plated bronze.

Recording density was 100 characters per inch on eight tracks. Early IBM 7 track tape drives were floor-standing and used vacuum columns to mechanically buff

Proletariat (party)

Proletariat is the name used to refer to three Polish political parties: The First Proletariat called the Great Proletariat. The Second Proletariat called the Small Proletariat; the Third Proletariat. The First Proletariat was the first Polish socialist party, it was founded in 1882 by Ludwik Waryński from members of Warsaw socialist circles. At a meeting in Vilna in 1883, The First Proletariat joined with parties from other cities in creating a central committee composed of Waryński, Stanisław Kunicki, Tadeusz Rechniewski, others. Other important party activists were Edmund Płoski, Maria Bohuszewiczówna, Marian Stefan Ulrych, Aleksandra Jentysówna, Henryk Dulęba. In March 1884 the First Proletariat formed an alliance with the People's Will and embraced political and economic terror as a means to combat autocracy; the party opposed the Polish independence movement. In 1883-1884 several of the chief activists were arrested and the party lost much of its power. In July 1886 the party was crushed as many of its remaining members were executed.

The First Proletariat disbanded that year, but many of its traditions would be continued by the Second Proletariat. The Second Proletariat was founded in 1888 by merging the remaining organization of the First Proletarian and a student group led by Ludwik Kulczycki; the Second Proletariat embraced terror as means to combat autocracy. Representatives of the Second Proletariata participated in the founding congress of the Second International in Paris in 1889. In 1891 a faction emerged in the party. In 1893 the party merged with three other parties to create the Polish Socialist Party; the Third Proletariat was created in 1900 as a splinter group of the Polish Socialist Party. It was led by Ludwik Kulczycki and, beset by Tsarist repression, ceased operations in 1909. Орехов А. М. Социал-демократическое движение в России и польские революционеры. Orekhov A. Social Democratic movement in Russia and the Polish revolutionaries. 1887—1893 гг. 1887–1893 years. М. 1973 MA, 1973 Baumgarten L. Dzieje Wielkiego Proletariatu.

Baumgarten L. Dzieje Wielkiego Proletariatu. Warszawa 1966 Warszawa 1966 Targalski J. Geneza Polskiej Partii Socjalistycznej Proletariat. Targalski J. Geneza Polskiej Partii Socjalistycznej Proletariat. «Z pola walki», 1973, № 2—3. «Z pola walki», 1973, № 2-3

Minuscule 697

Minuscule 697, ε1389, is a Greek minuscule manuscript of the New Testament, on parchment. Palaeographically it has been assigned to the 13th century; the manuscript has complex contents. Scrivener labelled it as 601e; the codex contains the text of the four Gospels on 350 parchment leaves. The text is written in one column per 25 lines per page; the text is divided according to the numbers appearing at the margin. There is a division according to the Ammonian Sections, but there are no references to the Eusebian Canons, it contains a portrait of the Evangelist. According to Scrivener it is "beautifully written in black ink, the first page of each Gospel being in gold". Kurt Aland. According to the Claremont Profile Method it represents textual group 22a in Luke 1, Luke 10, Luke 20. Scrivener dated the manuscript to the 14th century. Gregory dated it to the 14th century; the manuscript is dated by the INTF to the 13th century. The manuscript was found in a village near Corinth, bought by C. L. Merlin, British vice-consul in Athens, in 1865.

It was added to the list of New Testament manuscripts by Gregory. It was examined and described by S. T. Bloomfield, Dean Burgon. Gregory saw the manuscript in 1883; the manuscript is housed at the British Library in London. List of New Testament minuscules Biblical manuscript Textual criticism S. T. Bloomfield, Critical Annotations: Additional and Supplementary on the New Testament