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ZX Spectrum

The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research. Referred to during development as the ZX81 Colour and ZX82, it was launched as the ZX Spectrum by Sinclair to highlight the machine's colour display, compared with the black and white display of its predecessor, the ZX81; the Spectrum was released as eight different models, ranging from the entry level with 16 KB RAM released in 1982 to the ZX Spectrum +3 with 128 KB RAM and built in floppy disk drive in 1987. The Spectrum was among the first mainstream-audience home computers in the UK, similar in significance to the Commodore 64 in the US; the introduction of the ZX Spectrum led to a boom in companies producing software and hardware for the machine, the effects of which are still seen. Some credit it as the machine. Licensing deals and clones followed, earned Clive Sinclair a knighthood for "services to British industry"; the Commodore 64, Dragon 32, Oric-1, Oric Atmos, BBC Micro and the Amstrad CPC range were rivals to the Spectrum in the UK market during the early 1980s.

The machine was discontinued in 1992. The Spectrum is based on a Zilog Z80 A CPU running at 3.5 MHz. The original model has 16 KB of ROM and either 16 KB or 48 KB of RAM. Hardware design was by Richard Altwasser of Sinclair Research, the outward appearance was designed by Sinclair's industrial designer Rick Dickinson. Video output is through an RF modulator and was designed for use with contemporary television sets, for a simple colour graphic display. Text can be displayed using 32 columns × 24 rows of characters from the ZX Spectrum character set or from a set provided within an application, from a palette of 15 shades: seven colours at two levels of brightness each, plus black; the image resolution is 256×192 with the same colour limitations. To conserve memory, colour is stored separate from the pixel bitmap in a low resolution, 32×24 grid overlay, corresponding to the character cells. In practice, this means that all pixels of an 8x8 character block share one foreground colour and one background colour.

Altwasser received a patent for this design. An "attribute" consists of a foreground and a background colour, a brightness level and a flashing "flag" which, when set, causes the two colours to swap at regular intervals; this scheme leads to what was dubbed colour clash or attribute clash, where a desired colour of a specific pixel could not be selected. This became a distinctive feature of the Spectrum, meaning programs games, had to be designed around this limitation. Other machines available around the same time, for example the Amstrad CPC or the Commodore 64, did not suffer from this limitation; the Commodore 64 used colour attributes in a similar way, but a special multicolour mode and hardware sprites were used to avoid attribute clash. Sound output is through a beeper on the machine itself, capable of producing one channel with 10 octaves. Software was available that could play two channel sound; the machine includes an expansion bus edge connector and 3.5 mm audio in/out ports for the connection of a cassette recorder for loading and saving programs and data.

The "ear" port has a higher output than the "mic" and is recommended for headphones, with "mic" for attaching to other audio devices as line in. It was manufactured in Scotland, in the now closed Timex factory; the machine's Sinclair BASIC interpreter is stored in ROM and was written by Steve Vickers on contract from Nine Tiles Ltd. The Spectrum's chiclet keyboard is marked with BASIC keywords. For example, pressing "G" when in programming mode would insert the BASIC command GO TO; the BASIC interpreter was developed from that used on the ZX81 and a ZX81 BASIC program can be typed into a Spectrum unmodified, but Spectrum BASIC included many extra features making it easier to use. The ZX Spectrum character set was expanded from that of the ZX81, which did not feature lower-case letters. Spectrum BASIC included extra keywords for the more advanced display and sound, supported multi-statement lines; the cassette interface was much more advanced and loading around five times faster than the ZX81, unlike the ZX81, the Spectrum could maintain the TV display during tape storage and retrieval operations.

As well as being able to save programs, the Spectrum could save the contents of arrays, the contents of the screen memory, the contents of any defined range of memory addresses. Rick Dickinson came up with a number of designs for the "ZX82" project before the final ZX Spectrum design. A number of the keyboard legends changed during the design phase including ARC becoming CIRCLE, FORE becoming INK and BACK becoming PAPER; the Spectrum reused a number of design elements of the ZX81: The ROM code for things such as floating point calculations and expression parsing were similar. The simple keyboard decoding and cassette interfaces were nearly identical; the central ULA integrated circuit was somewhat similar although it implemented the major enhancement over the ZX81: A hardware based television raster generator that indirectly gave the new machine four times as much processing power as the ZX81 due to the Z80 now being released from this video generation task. A bug in the ULA as designed meant that the keyboard did not always scan and was rectified by a "dead cock


Newbridge-on-Usk is a hamlet in the village and parish of Tredunnock, near Usk, south east Wales, in the United Kingdom. Newbridge-on-Usk is located on the River Usk 5 miles to the north of Newport in the Vale of Usk. Situated below the steep Wentwood escarpment, it lies between the historic towns of Caerleon and Usk, about 4 miles from the junction 24 of the M4 motorway via the B4237 Coldra, B4236 and Catsash Road. At the river is the Newbridge Inn, once owned by radio and television presenter Chris Evans; the inn is run by the Celtic Manor Resort. It offers bed and breakfast facilities in six newly-built, en-suite rooms and has an AA-award winning restaurant; the elegant red sandstone three-arched New Bridge dates from 1779 and is said to have been designed by William Edwards. It is Grade II* listed, it stands at the Normal Tidal Limit of the River Usk. Map sources for Newbridge-on-Usk photos of Newbridge-on-Usk and surrounding area


Sludge is a semi-solid slurry that can be produced from a range of industrial processes, from water treatment, wastewater treatment or on-site sanitation systems. For example, it can be produced as a settled suspension obtained from conventional drinking water treatment, as sewage sludge from wastewater treatment processes or as fecal sludge from pit latrines and septic tanks; the term is sometimes used as a generic term for solids separated from suspension in a liquid. Sludge can consist of a variety such as animal manure. Industrial wastewater treatment plants produce solids that are referred to as sludge; this can be generated from physical-chemical processes. In the activated sludge process for wastewater treatment, the terms "waste activated sludge" and "return activated sludge" are used. In food processing and beverage-making industries, sludge can have high protein content and other nutrients that can be used for beneficial purposes such as animal feed, thereby avoiding disposal at a landfill

Ezra Abbot

Ezra Abbot was an American biblical scholar. He graduated from Bowdoin College in 1840. In 1847, at the request of Prof. Andrews Norton, he went to Cambridge, where he was principal of a public school until 1856, he was assistant librarian of Harvard University from 1856 to 1872, planned and perfected an alphabetical card catalog, combining many of the advantages of the ordinary dictionary catalogs with the grouping of the minor topics under more general heads, characteristic of a systematic catalogue. From 1872 until his death he was Bussey Professor of New Testament Criticism and Interpretation in the Harvard Divinity School. Abbot's studies were chiefly in Oriental languages and textual criticism of the New Testament, though his work as a bibliographer showed such results as the exhaustive list of writings on the doctrine of the future life, appended to W. R. Alger's History of the Doctrine of a Future Life, as it has prevailed in all Nations and Ages, published separately in 1864. Abbot's publications, though always of the most thorough and scholarly character, were to a large extent dispersed in the pages of reviews, concordances, texts edited by others, Unitarian controversial treatises, etc.

However, he took a more conspicuous and personal part in the preparation of the enlarged American edition of Dr. William Smith's Dictionary of the Bible, to which he contributed more than 400 articles, as well as improving the bibliographical completeness of the work, he was an efficient member of the American revision committee for the Revised Version of the King James Bible, helped prepare Caspar René Gregory's Prolegomena to the revised Greek New Testament of Constantin von Tischendorf. He was one of the 32 founding members of the Society of Biblical Literature in 1880, his principal single work, representing his scholarly method and conservative conclusions, was The Authorship of the Fourth Gospel: External Evidences a lecture. In spite of the compression due to its form, this work was up to that time the ablest defense, based on external evidence, of the Johannine authorship, the most complete treatment of the relation of Justin Martyr to this gospel. Abbot was elected a Fellow of the American Academy of Arts and Sciences in 1861.

Though a layman, he received the degree of S. T. D. from Harvard in 1872, that of D. D. from Edinburgh in 1884. Abbot, Ezra. A Critical Greek and English concordance of the New Testament. Philadelphia, PA: Lippincott. OCLC 17645776. - revised by Ezra Abbot ———. The authorship of the Fourth Gospel: external evidences. Boston, MA: G. H. Ellis. OCLC 1152377. ———. Notes on Scrivener's "Plain introduction to the criticism of the New Testament". Boston, MA: Houghton, Mifflin. OCLC 1361022. ———. The authorship of the Fourth Gospel, other critical essays: selected from the published papers of the late Ezra Abbot. Boston, MA: G. H. Ellis. OCLC 2937371. ———. "On the comparative antiquity of the Sinaitic and Vatican manuscripts of the Greek Bible". Journal of the American Oriental Society. American Oriental Society. 10: 189–200. Attribution This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed.. "Abbot, Ezra". Encyclopædia Britannica. 1. Cambridge University Press. P. 22. Endnote: See S. J. Barrows, Ezra Abbot.

Appleton's Cyclopedia of American Biography, edited by James Grant Wilson, John Fiske and Stanley L. Klos. Six volumes, New York: D. Appleton and Company, 1887-1889 Abbot, Ezra in the Christian Cyclopedia The historical records of Ezra Abbot are in the Andover-Harvard Theological Library at Harvard Divinity School in Cambridge, Massachusetts

Callander railway station

Callander was a railway station located in Callander, in the council area of Stirling, Scotland. The first station was a terminus opened by the Dunblane and Callander Railway on 1 July 1858, it was closed on 1 June 1870 when the second station was opened along with the first section of the Callander and Oban Railway, between Callander and Glenoglehead. The original terminal station of the Dunblane and Callander Railway become a goods yard; the station underwent expansion in 1882. Closure came on 1 November 1965, when the service between Callander and Dunblane ended as part of the Beeching Axe; the section between Callander and Crianlarich had been closed on 27 September that year following a landslide at Glen Ogle. The track through the station was lifted in late 1968 and some demolition work was carried out; the station building itself was demolished in Spring 1973, the station site is now a car park, though a small section of the down platform still exists. The cast iron road bridge to the east of the station was infilled in 2012.

The impressive iron-work on the bridge was refurbished at the same time as the infilling. The site of the original Dunblane and Callander terminal station is now occupied by housing; the enlarged layout of 1882 was controlled from two signal boxes that opened on 1 August of that year. Both boxes stood on the north side of the line; the East box had 45 levers, while the West box had 27. Both signal boxes closed on 30 October 1965. Callander & Oban Junction was situated three quarters of a mile east of Callander station; this location marked the beginning of the Callander and Oban Railway, being where it diverged from the older Dunblane and Callander Railway. Callander & Oban Junction signal box opened on 1 June 1870; the box was replaced on 2 November 1902. The replacement box had 27 levers. On 10 April 1938, the double track line between Callander station and C&O Junction was converted to two single lines. One line became the main single line, the other was retained as a siding for access to the goods yard.

All connections between the two lines at C&O Junction were severed and the signal box there was closed. All the mileposts on the C&OR were measured from Callander & Oban Junction, including the branch line to Ballachulish and the surviving section of the line, between Crianlarich and Oban. Butt, R. V. J.. The Directory of Railway Stations: details every public and private passenger station, halt and stopping place and present. Sparkford: Patrick Stephens Ltd. ISBN 978-1-85260-508-7. OCLC 60251199. Jowett, Alan. Jowett's Railway Atlas of Great Britain and Ireland: From Pre-Grouping to the Present Day. Sparkford: Patrick Stephens Ltd. ISBN 978-1-85260-086-0. OCLC 22311137. RAILSCOT on Dunblane and Callander Railway RAILSCOT on Callander and Oban Railway Callander station on navigable 1925 map

The Elf Mound

"The Elf Mound" is a literary fairy tale by Danish poet and author Hans Christian Andersen. The tale is about a feast held in an elf mound for the Goblin Chief of Norway and his two sons, both of whom are expected to select elf brides; the tale was published in Copenhagen, Denmark by C. A. Reitzel in April 1845. Two lizards scramble about the entrance to the Elf Mound, commenting on the hustle and bustle within, they have heard the elf maidens are practicing new dances and both wonder the reason why. An old maid elf summons a raven to deliver invitations to an important event; the elf maidens begin their misty dances. The dishes for the night's festivities include skewered frogs, fungus salad made of mushroom seed, hemlock; the king polishes his crown and tells his inquisitive youngest daughter that he has arranged marriages between two of his daughters and two of the sons of the Goblin Chief of Norway, who all arrive at that moment with pomp. The feast is held and the two sons prove rowdy and boisterous.

The elf maidens are paraded as potential brides. The Goblin Chief is so delighted. Dawn approaches, the old maid elf wants to close the shutters; the two sons of the Goblin King hurry outside to continue their tomfoolery and horseplay, leaving without selecting brides. The tale was first published by C. A. Reitzel in Copenhagen, Denmark on 7 April 1845 in New Fairy Tales. First Volume. Third Collection. 1845.. "The Elf Mound" was the first tale in the collection that included "The Red Shoes", "The Jumpers", "The Shepherdess and the Chimney Sweep", "Holger the Dane". The tale was republished 18–December 1849 as a part of Fairy Tales. 1850. and again 30 March 1863 as a part of Fairy Tales and Stories. 1863. The tale has since been published in various languages around the world; the most notable reference to the story is the Norwegian stage play Peer Gynt in which the Mountain King, is modeled on the Norwegian troll king in Andersen's tale. Henrik Ibsen was inspired by Andersen at the time; the Dutch composer Johan Wagenaar has composed an Elverhoi-ouverture Op. 48.

List of works by Hans Christian Andersen "The Elf Mound" English translation by Jean Hersholt Elverhøi Original Danish text Elverhøi Original manuscript