The TRS-80 Micro Computer System is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their RadioShack stores. The name is an abbreviation of Z-80 microprocessor, it is one of mass-marketed retail home computers. The TRS-80 has a full-stroke QWERTY keyboard, the Zilog Z80 processor, 4 KB DRAM standard memory, small size and desk footprint, floating-point BASIC programming language, standard 64-character/line video monitor, a starting price of US$600. An extensive line of upgrades and add-on hardware peripherals for the TRS-80 was developed and marketed by Tandy/RadioShack; the basic system can be expanded with up to 48 KB of RAM, up to four floppy disk drives and/or hard disk drives. Tandy/RadioShack provided full-service support including upgrade and training services in their thousands of stores worldwide. By 1979, the TRS-80 had the largest selection of software in the microcomputer market; until 1982, the TRS-80 was the best-selling PC line, outselling the Apple II series by a factor of five according to one analysis.
In mid-1980, the broadly compatible TRS-80 Model III was released. The Model I was discontinued shortly thereafter due to stricter FCC regulations on radio-frequency interference to nearby electronic devices. In April 1983 the Model III was succeeded by the compatible Model 4. Following the original Model I and its compatible descendants, the TRS-80 name became a generic brand used on other technically unrelated computer lines sold by Tandy, including the TRS-80 Model II, TRS-80 Model 2000, TRS-80 Model 100, TRS-80 Color Computer and TRS-80 Pocket Computer. In the mid-1970s, Tandy Corporation's RadioShack division was a successful American chain of more than 3,000 electronics stores. After buyer Don French purchased a MITS Altair kit computer, he began designing his own and showed it to vice president of manufacturing John Roach. Although the design did not impress Roach, the idea of selling a microcomputer did; when the two men visited National Semiconductor in California in mid-1976, Steve Leininger's expertise on the SC/MP microprocessor impressed them.
National executives refused to provide Leininger's contact information when French and Roach wanted to hire him as a consultant, but they found Leininger working part-time at Byte Shop and he and French began working together in June 1976. The company envisioned a kit, but Leininger persuaded the others that because "too many people can't solder", a preassembled computer would be better. Tandy had 11 million customers that might buy a microcomputer, but it would be much more expensive than the US$30 median price of a RadioShack product, a great risk for the conservative company. Executives feared losing money as Sears did with Cartrivision, many opposed the project; as the popularity of CB radio—at one point comprising more than 20% of RadioShack's sales—declined, the company sought new products. In December 1976 French and Leininger received official approval for the project but were told to emphasize cost savings. In February 1977 they showed their prototype, running a simple tax-accounting program, to Charles Tandy, head of Tandy Corporation.
The program crashed as the computer could not handle the US$150,000 figure that Tandy typed in as his salary, the two men added support for floating-point math to its Tiny BASIC to prevent a recurrence. After the demonstration Tandy revealed that he had leaked the computer's existence to the press, so the project was approved. MITS sold 1,000 Altairs in February 1975, was selling 10,000 a year. Leininger and French suggested that RadioShack could sell 50,000 computers, but others disagreed and suggested 1,000 to 3,000 per year at the target US$199 price. Roach persuaded Tandy to agree to build 3,500—the number of RadioShack stores—so that each store could use a computer for inventory purposes if they did not sell. Having spent less than US$150,000 on development, RadioShack announced the TRS-80 at a New York City press conference on August 3, 1977, it cost a RadioShack tape recorder as datacassette storage. The company hoped that the new computer would help RadioShack sell higher-priced products, improve its "schlocky" image among customers.
Small businesses were the primary target market, followed by educators consumers and hobbyists. Although the press conference did not receive much media attention because of a terrorist bombing elsewhere in the city, the computer received much more publicity at the Personal Computer Faire in Boston two days later. A front-page Associated Press article discussed the novelty of a large consumer-electronics company selling a home computer that could "do a payroll for up to 15 people in a small business, teach children mathematics, store your favorite recipes or keep track of an investment portfolio, it can play cards." Six sacks of mail arrived at Tandy headquarters asking about the computer, over 15,000 people called to purchase a TRS-80—paralyzing the company switchboard—and 250,000 joined the waiting list with a $100 deposit. Despite the internal skepticism, RadioShack aggressively entered the
A hex map, hex board, or hex grid is a game board design used in wargames of all scales. The map is subdivided into small regular hexagons of identical size; the primary advantage of a hex map over a traditional square grid map is that the distance between the center of each and every pair of adjacent hex cells is the same. By comparison, in a square grid map, the distance from the center of each square cell to the center of the four diagonal adjacent cells it shares a corner with is greater than the distance to the center of the four adjacent cells it shares an edge with; this equidistant property of all adjacent hexes is desirable for games in which the measurement of movement is a factor. The other advantage is the fact. One disadvantage of a hex map is that hexes have adjacent cells in only six directions instead of eight, as in a square grid map. Cells will form continuous straight lines "up" and "down", or "north" and "south", in which case the other four adjacent cells lie "north-west", "north-east", "south-west" and "south-east".
As a result, no hex cell has an adjacent hex cell lying directly east or west of it, making movement in a straight line east or west impossible. Instead, paths in these directions, any other path that does not bisect one of the six cell edges, will "zig-zag". Games that traditionally use the four cardinal directions, or otherwise suit a square grid, may adapt to a hex grid in different ways. For example, hexagonal chess replaces the four directions of orthogonal movement with the six directions to adjacent cells, through cell edges; the four directions of diagonal movement are replaced with the six directions that lie through vertices of the cell. A three-colour grid aids in visualising this movement, since it preserves the traditional chessboard's property that pieces moving diagonally land only on cells of the same colour; the hex map has been a favourite for game designers since 1961, when Charles S. Roberts of the Avalon Hill game company published the second edition of Gettysburg with a hex map.
The hex grid is a distinguishing feature of the games from many wargame publishers, a few other games. The hex map has been popular for role-playing game wilderness maps, they were used in the Dragons boxed sets of the 1980s and related TSR products. GDW used a hex grid map in mapping space for their science-fiction RPG Traveller. A few abstract games are played on a hex grid, such as the six games of the GIPF series as well as Hex and the television game show based on it, Blockbusters. Chinese Checkers is played on a hex grid and several variants of chess have been invented for a hex board. Early examples of strategy video games that use hex maps include 1983's Nobunaga's Ambition, 1989's Military Madness, 1991's Master of Monsters; the first Civilization had a hex map version during development, but designers decided against it because "the world was not ready... it was too freaky". While the first four iterations of the popular Civilization computer game franchise used square maps, Civilization V and Civilization VI use hexagonal maps.
Other games that uses hex maps are The Battle for Wesnoth, Dragon Age Journeys, Heroes of Might and Magic III, Forge of Empires. Hexxagon, a board game Hexagonal tiling mkhexgrid, a hex grid and hex paper utility Free online hexagonal graph paper PDF generator Hexographer, a program for making role-playing game wilderness hex maps in a "classic" style Hextml, an online program to make hex maps GM Friend hex mapping tool, an online program to make hex maps with a random map generator RedBlobGames, Hexagonal Grids, a reference for hexagonal grid algorithms supraHex A supra-hexagonal map for analysing high-dimensional omics data. Mathematical discussion of implementing the x,y,z axis in hexagonal applications Unreal Engine 4 HexMap grid extension
Terrain or relief involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level; the Latin word terra means "earth." In physical geography, terrain is the lay of the land. This is expressed in terms of the elevation and orientation of terrain features. Terrain affects distribution. Over a large area, it can affect climate patterns; the understanding of terrain is critical for many reasons: The terrain of a region determines its suitability for human settlement: flatter, alluvial plains tend to have better farming soils than steeper, rockier uplands. In terms of environmental quality, agriculture and other interdisciplinary sciences. Complex arrays of relief data are used as input parameters for hydrology transport models to allow prediction of river water quality. Understanding terrain supports soil conservation in agriculture. Contour ploughing is an established practice enabling sustainable agriculture on sloping land.
Terrain is militarily critical because it determines the ability of armed forces to take and hold areas, move troops and material into and through areas. An understanding of terrain is basic to both offensive strategy. Terrain is important in determining weather patterns. Two areas geographically close to each other may differ radically in precipitation levels or timing because of elevation differences or a "rain shadow" effect. Precise knowledge of terrain is vital in aviation for low-flying routes and maneuvers and airport altitudes. Terrain will affect range and performance of radars and terrestrial radio navigation systems. Furthermore, a hilly or mountainous terrain can impact the implementation of a new aerodrome and the orientation of its runways. Relief refers to the quantitative measurement of vertical elevation change in a landscape, it is the difference between maximum and minimum elevations within a given area of limited extent. The relief of a landscape can change with the size of the area over which it is measured, making the definition of the scale over which it is measured important.
Because it is related to the slope of surfaces within the area of interest and to the gradient of any streams present, the relief of a landscape is a useful metric in the study of the Earth's surface. Relief energy, which may be defined inter alia as "the maximum height range in a regular grid", is an indication of the ruggedness or relative height of the terrain. Geomorphology is in large part the study of the formation of topography. Terrain is formed by concurrent processes: Geological processes: Migration of tectonic plates and folding, mountain formation, volcanic eruptions, etc. Erosional processes: glacial, wind and gravitational. Extraterrestrial: meteorite impacts. Tectonic processes such as orogenies and uplifts cause land to be elevated, whereas erosional and weathering processes wear the land away by smoothing and reducing topographic features; the relationship of erosion and tectonics reaches equilibrium. These processes are codependent, however the full range of their interactions is still a topic of debate.
Land surface parameters are quantitative measures of various morphometric properties of a surface. The most common examples are used to derive slope or aspect of a terrain or curvatures at each location; these measures can be used to derive hydrological parameters that reflect flow/erosion processes. Climatic parameters are based on the modelling of solar air flow. Land surface objects, or landforms, are definite physical objects that differ from the surrounding objects; the most typical examples airlines of watersheds, stream patterns, break-lines, pools or borders of specific landforms. Applications of global navigation satellite systems Cartographic relief depiction Digital terrain model Geographic information system Geomorphometry Hypsometry Isostasy Physical terrain model Relief ratio Subterranea Terrain awareness and warning system Terrane Topography Boots on the ground. On military terrain from the perspective of the combat soldier. By Professor Derek Gregory Google Maps Bing Maps The dictionary definition of terrain at Wiktionary
A board game is a tabletop game that involves counters or pieces moved or placed on a pre-marked surface or "board", according to a set of rules. Some games are based on pure strategy. Games have a goal that a player aims to achieve. Early board games represented a battle between two armies, most modern board games are still based on defeating opponents in terms of counters, winning position, or accrual of points. There are many varieties of board games, their representation of real-life situations can range from having no inherent theme, like checkers, to having a specific theme and narrative, like Cluedo. Rules can range from the simple, like Tic-tac-toe, to those describing a game universe in great detail, like Dungeons & Dragons – although most of the latter are role-playing games where the board is secondary to the game, serving to help visualize the game scenario; the time required to learn to play or master a game varies from game to game, but is not correlated with the number or complexity of rules.
Board games have been played in societies throughout history. A number of important historical sites and documents shed light on early board games such as Jiroft civilization gameboards in Iran. Senet, found in Predynastic and First Dynasty burials of Egypt, c. 3500 BC and 3100 BC is the oldest board game known to have existed. Senet was pictured in a fresco found in Merknera's tomb. From predynastic Egypt is Mehen. Hounds and Jackals another ancient Egyptean board game appeared around 2000 BC; the first complete set of this game was discovered from a Theban tomb that dates to the 13th Dynasty. This game was popular in Mesopotamia and the Caucasus. Backgammon originated in ancient Persia over 5,000 years ago. Chess and Chaupar originated in India. Go and Liubo originated in China. Patolli originated in Mesoamerica played by the ancient Aztec and The Royal Game of Ur was found in the Royal Tombs of Ur, dating to Mesopotamia 4,600 years ago; the earliest known games list is the Buddha games list. In 17th and 18th century colonial America, the agrarian life of the country left little time for game playing though draughts and card games were not unknown.
The Pilgrims and Puritans of New England frowned on game playing and viewed dice as instruments of the devil. When the Governor William Bradford discovered a group of non-Puritans playing stool-ball, pitching the bar, pursuing other sports in the streets on Christmas Day, 1622, he confiscated their implements, reprimanded them, told them their devotion for the day should be confined to their homes. In Thoughts on Lotteries Thomas Jefferson wrote: Almost all these pursuits of chance produce something useful to society, but there are some which produce nothing, endanger the well-being of the individuals engaged in them or of others depending on them. Such are games with cards, billiards, etc, and although the pursuit of them is a matter of natural right, yet society, perceiving the irresistible bent of some of its members to pursue them, the ruin produced by them to the families depending on these individuals, consider it as a case of insanity, quoad hoc, step in to protect the family and the party himself, as in other cases of insanity, imbecility, etc. and suppress the pursuit altogether, the natural right of following it.
There are some other games of chance, useful on certain occasions, injurious only when carried beyond their useful bounds. Such are insurances, raffles, etc; these they do not take their regulation under their own discretion. The board game Traveller's Tour Through the United States and its sister game Traveller's Tour Through Europe were published by New York City bookseller F. & R. Lockwood in 1822 and today claims the distinction of being the first board game published in the United States; as the U. S. shifted from agrarian to urban living in the 19th century, greater leisure time and a rise in income became available to the middle class. The American home, once the center of economic production, became the locus of entertainment and education under the supervision of mothers. Children were encouraged to play board games that developed literacy skills and provided moral instruction; the earliest board games published in the United States were based upon Christian morality. The Mansion of Happiness, for example, sent players along a path of virtues and vices that led to the Mansion of Happiness.
The Game of Pope and Pagan, or The Siege of the Stronghold of Satan by the Christian Army pitted an image on its board of a Hindu woman committing suttee against missionaries landing on a foreign shore. The missionaries are cast in white as "the symbol of innocence and hope" while the pope and pagan are cast in black, the color of "gloom of error, and... grief at the daily loss of empire". Commercially produced board games in the mid-19th century were monochrome prints laboriously hand-colored by teams of low-paid young factory women. Advances in paper making and printmaking during the period enabled the commercial production of inexpensive board games; the most significant advance was the development of chromolithography, a technological achievement that made bold, richly colored images available at affordable prices. Games cost as little as US$.25 for a small boxed card game to $3.00 for more elaborate games. American Protestants believed a virtuous life led to success, but the belief was challenged mid-century when the country embraced materialism and c
The mail or post is a system for physically transporting postcards and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal systems have been established as government monopolies, with a fee on the article prepaid. Proof of payment is in the form of adhesive postage stamps, but postage meters are used for bulk mailing. Modern private postal systems are distinguished from national postal agencies by the names "courier" or "delivery service". Postal authorities have functions other than transporting letters. In some countries, a postal and telephone service oversees the postal system, in addition to telephone and telegraph systems; some countries' postal systems allow for savings handle applications for passports. The Universal Postal Union, established in 1874, includes 192 member countries and sets the rules for international mail exchanges; the word mail comes from the Medieval English word male, referring to pack.
It was spelled that way until the 17th century, is distinct from the word male. The French have a similar word, malle for a trunk or large box, mála is the Irish term for a bag. In the 17th century, the word mail began to appear as a reference for a bag that contained letters: "bag full of letter". Over the next hundred years the word mail began to be applied to the letters themselves, the sack as the mailbag. In the 19th century the British referred to mail as being letters that were being sent abroad, post as letters that were for localized delivery. S. the U. S. Postal Service delivers the mail; the term email first appeared in the 1970s. The term snail-mail is a retronym to distinguish it from the quicker email. Various dates have been given for its first use. Post is derived from Medieval French poste, which stems from the past participle of the Latin verb ponere; the practice of communication by written documents carried by an intermediary from one person or place to another certainly dates back nearly to the invention of writing.
However, development of formal postal systems occurred much later. The first documented use of an organized courier service for the diffusion of written documents is in Egypt, where Pharaohs used couriers for the diffusion of their decrees in the territory of the State; the earliest surviving piece of mail is Egyptian, dating to 255 BC. The first credible claim for the development of a real postal system comes from Ancient Persia, but the point of invention remains in question; the best documented claim attributes the invention to the Persian King Cyrus the Great, who mandated that every province in his kingdom would organize reception and delivery of post to each of its citizens. He negotiated with neighbouring countries to do the same and had roads built from the city of Post in Western Iran all the way up to the city of Hakha in the East. Other writers credit his successor Darius I of Persia. Other sources claim much earlier dates for an Assyrian postal system, with credit given to Hammurabi and Sargon II.
Mail may not have been the primary mission of this postal service, however. The role of the system as an intelligence gathering apparatus is well documented, the service was called angariae, a term that in time came to indicate a tax system; the Old Testament makes mention of this system: Ahasuerus, king of Medes, used couriers for communicating his decisions. The Persian system worked on stations, where the message carrier would ride to the next post, whereupon he would swap his horse with a fresh one, for maximum performance and delivery speed. Herodotus described the system in this way: "It is said that as many days as there are in the whole journey, so many are the men and horses that stand along the road, each horse and man at the interval of a day's journey; the verse prominently features on New York's James Farley Post Office, although it has been rephrased to Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds. The economic growth and political stability under the Mauryan empire saw the development of impressive civil infrastructure in ancient India.
The Mauryans developed early Indian mail service as well as public wells, rest houses, other facilities for the common public. Common chariots called. Couriers were used militarily by kings and local rulers to deliver information through runners and other carriers; the postmaster, the head of the intelligence service, was responsible for ensuring the maintenance of the courier system. Couriers were used to deliver personal letters. In South India, the Wodeyar dynasty of the Kingdom of Mysore used mail service for espionage purposes thereby acquiring knowledge related to matters that took place at great distances. By the end of the 18th century, the postal system in India had reached impressive levels of efficiency. According to British national Thomas Broughton, the Maharaja of Jodhpur sent daily offerings of fresh flowers from his capital to Nathadvara, they arrived in time for the first religious Darshan at sunrise; this system underwent complete modernization when the British Raj established its full control over India.
The Post Offi
Squad Leader is a tactical level board wargame published by Avalon Hill in 1977. It was designed by John Hill and focuses on infantry combat in Europe during World War II. One of the most complex wargames of its time, Squad Leader is the natural extension of the trend towards greater realism initiated by several earlier games, including Avalon Hill's own PanzerBlitz and Panzer Leader; those two earlier games were larger in scope, with counters representing platoons and map hexes measuring 250 metres across, compared to Squad Leader's 40 meter hexes and squad sized units. The original Squad Leader was produced in time to debut at Origins 1977. Avalon Hill sold well in excess of 100,000 games of Squad Leader, making it one of the most successful wargames made. Combined with the sales of Advanced Squad Leader, its sales totaled over 1 million copies by 1997. Pieces in Squad Leader represent regular squads and vehicle crews, elite squads, individual leaders, support weapons, vehicles; the original game contains counters representing the German and American armies.
Russian troops are portrayed as poorly armed and with fewer leaders, but with the capacity to become "berserk" in combat. US troops are shown as having unusually high firepower, but with lower base morale than German or Soviet troops, representing the supposed greater tendency of more individualistic Americans to break from their orders or the group under fire - however, American troops are easier to rally under fire, as they were exempt from the usual penalty paid by broken squads in these circumstances. British troops, when added to the game system, are shown as similar to the Germans, albeit with somewhat inferior equipment; the mapboards are divided into hexagonal grids with each hex said to represent 40 metres of terrain, the result of the designer being asked what the ground scale was, rolling a die and it coming up'four'. In reality, European village streets are not 40 meters across, for example. Time was said to be two minutes per turn, though the developer admits that this is inexact and that each game turn should be considered a "module of time, such that the events can occur and interact with one another."
As well, by being geomorphic mapboards, increased flexibility is given to scenario designers as well as "design your own" players. The semi-simultaneous system of play developed in the mid-1970s can be seen in Squad Leader's sequence of play; each turn consists of two player turns, each of which have eight "phases": Rally phase Prep fire phase Movement phase Defensive fire phase Advancing fire phase Rout phase Advance phase, the close combat phase The name of the game is a misnomer, as in most ways the player assumes the role of a company commander. The squad leaders in Squad Leader are "factored in" to the squad counters, only exceptional leaders - officers and NCOs - are portrayed separately, by their own counters. Leaders can exert a favorable influence on the firing of support weapons, or the morale rolls of squads with whom they are stacked, although if a leader fails a morale check the squads stacked with it must check for morale a second time. Most scenarios give each player speaking, enough simulated men to make up a company, though order of battle is not precise and most scenarios only give a flavor of what the real life battles were like rather than a direct simulation.
One aspect of the game that adds to its popularity are the generic "geomorphic" mapboards, each of which can be aligned to any edge of the same length to any other mapboard. This allows for an unlimited number of combinations to create any terrain situation, including player designed scenarios. Printed overlays, first introduced in the gamette GI: Anvil of Victory provide additional terrain types to mapboards. Line of sight is determined by sighting between the dots in the center of each hex. String can be used to check LOS, the printed terrain depictions on the photo-realistic maps are used to determine blockages; these LOS rules were innovative for board games. The original game contains mapboards mounted on heavy durable cardboard, expensive but a design feature long associated with Avalon Hill games; each mapboard measures 10 columns of hexes high by 32 hexes wide, numbered from hex A1 in the top left corner to hex GG10 in the lower right. The design philosophy that John Hill
Gettysburg is a board wargame produced by Avalon Hill which re-enacts the American Civil War battle of Gettysburg. Gettysburg was published in 1958, was the first board wargame based on a historical battle. Gettysburg has game mechanics similar to Avalon Hill's ground-breaking Tactics II. In particular, the combat results table favors attacking where one has a local superiority of numbers. Unlike Tactics II, Gettysburg gives each unit an orientation, an attacker can improve his odds by attacking a defender from the side or from the rear; the defender, can improve his odds by entrenching himself atop a hill. Charles S. Roberts, the founder of Avalon Hill, made the following comment about the game in 1983: In its original form, Gettysburg played something like a miniatures game; the map was marked off in a square grid, but this was used for tracking hidden movement, not to regulate regular movement. Movement instead used range cards, which were used to check firing ranges; the rectangular units were allowed to rotate on their centers before using the range card, the system gave bonuses for firing on a flank.
In 1961, the game was re-released, redone to use a hex grid, which appeared in other Avalon Hill games released that year. This proved a popular mechanism for regulating movement, with it being a staple of wargame design since, but Avalon Hill returned to a square grid for the 1964 edition of the game; the hex grid returned for the 1977 redesign of the game, which introduced multiple counters for each unit and expanded rules of unit formation. The rules additions were an attempt to simulate unit movement in columns and the delay and difficulty of changing formation into a line of battle. Separate counters represented flanks, which could be turned to join adjacent units' flanks or turned back to defend against expected assault. Although the grid was retained for the 1988 redesign, the multiple counters per unit and overly complex unit formation rules were discarded, this last iteration of the game bore a stronger resemblance to the 1961 version, save for the full color illustrated board of the 1977 edition.
A sister game, used the same game mechanics. These works are in the public domain because they were published in the United States before 1978 and although there was a copyright notice, the copyright was not renewed. Lou Zocchi comments: "With Gettysburg, Roberts created a game that evoked memories of brilliant commanders such as Lee and Jackson as players grew to understand the intricacies of their commands." Gary Gygax began playing Gettysburg by December 1958, Dave Arneson started playing the game in the early 1960s. Gygax and Arneson designed the seminal role-playing game Dungeons & Dragons in 1974, which grew out of their experience with wargames. Gettysburg at BoardGameGeek