Day of the Tentacle
Day of the Tentacle known as Maniac Mansion II: Day of the Tentacle, is a 1993 graphic adventure game developed and published by LucasArts. It is the sequel to the 1987 game Maniac Mansion; the game's plot follows Bernard Bernoulli and his friends Hoagie and Laverne as they attempt to stop the evil Purple Tentacle—a sentient, disembodied tentacle—from taking over the world. The player takes control of the trio and solves puzzles while using time travel to explore different periods of history. Dave Grossman and Tim Schafer co-led their first time in such a role; the pair carried over a limited number of elements from Maniac Mansion and forwent the character selection aspect to simplify development. Inspirations included the history of the United States. Day of the Tentacle is the eighth LucasArts title to use the SCUMM engine; the game was released on floppy disk and CD-ROM to critical acclaim and commercial success. Critics focused on comedic elements. Day of the Tentacle has featured in lists of "top" games published more than two decades after its release, aspects have been referenced in popular culture.
A remaster of Day of the Tentacle was developed by Schafer's current studio, Double Fine Productions, released on March 22, 2016, for the PlayStation 4, PlayStation Vita, Windows and OS X. Day of the Tentacle follows the point-and-click two-dimensional adventure game formula, first established by the original Maniac Mansion. Players direct the controllable characters around the game world by clicking with the computer mouse. To interact with the game world, players choose from a set of nine commands arrayed on the screen and on an object in the world; this was the last SCUMM game to use the original interface of having the bottom of the screen being taken up by a verb selection and inventory. Day of the Tentacle uses time travel extensively; the player, after completing certain puzzles, can freely switch between these characters, interacting with the game's world in the separate time periods. Certain small inventory items can be shared by placing the item into the "Chron-o-Johns", modified portable toilets that transport objects to the other time period, while other items are shared by leaving the item in a past time period to be picked up by a character in a future period.
Changes made to a past time period will affect a future one, many of the game's puzzles are based on the effect of time travel, aging of certain items, alterations of the time stream. For example, one puzzle requires the player, while in the future era where Purple Tentacle has succeeded, to send a medical chart of a Tentacle back to the past, having it used as the design of the American flag collecting one such flag in the future to be used as a Tentacle disguise to allow that character to roam freely; the whole original Maniac Mansion game can be played on a computer resembling a Commodore 64 inside the Day of the Tentacle game. Five years after the events of Maniac Mansion, Purple Tentacle—a mutant monster and lab assistant created by mad scientist Dr. Fred Edison—drinks toxic sludge from a river behind Dr. Fred's laboratory; the sludge causes him to grow a pair of flipper-like arms, develop vastly increased intelligence, a thirst for global domination. Dr. Fred plans to resolve the issue by killing Purple Tentacle and his harmless, friendly brother Green Tentacle, but Green Tentacle sends a plea of help to his old friend, the nerd Bernard Bernoulli.
Bernard travels to the Edison family motel with his two housemates, deranged medical student Laverne and roadie Hoagie, frees the tentacles. Purple Tentacle escapes to resume his quest to take over the world. Since Purple Tentacle's plans are flawless and unstoppable, Dr. Fred decides to use his Chron-o-John time machines to send Bernard and Hoagie to the day before to turn off his Sludge-o-Matic machine, thereby preventing Purple Tentacle's exposure to the sludge. However, because Dr. Fred used an imitation diamond rather than a real diamond as a power source for the time machine, the Chron-o-Johns breaks down in operation. Laverne is sent 200 years in the future, where humanity has been enslaved and Purple Tentacle rules the world from the Edison mansion, while Hoagie is dropped 200 years in the past, where the motel is being used by the Founding Fathers as a retreat to write the United States Constitution. Bernard is returned to the present. To salvage Dr. Fred's plan, Bernard must acquire a replacement diamond for the time machine, while both Hoagie and Laverne must restore power to their respective Chron-o-John pods by plugging them in.
To overcome the lack of electricity in the past, Hoagie recruits the help of Benjamin Franklin and Dr. Fred's ancestor, Red Edison, to build a superbattery to power his pod, while Laverne evades capture by the tentacles long enough to run an extension cord to her unit; the three send small objects back and forth in time through the Chron-o-Johns and make changes to history to help the others complete their tasks. Bernard uses Dr. Fred's family fortune of royalties from the Maniac Mansion TV series to purchase a real diamond, while his friends manage to power their Chron-o-Johns. Soon, the three are reunited in the present. Purple Tentacle arr
The Atari ST is a line of home computers from Atari Corporation and the successor to the Atari 8-bit family. The initial ST model, the 520ST, saw limited release in April–June 1985 and was available in July; the Atari ST is the first personal computer to come with a bitmapped color GUI, using a version of Digital Research's GEM released in February 1985. The 1040ST, released in 1986, is the first personal computer to ship with a megabyte of RAM in the base configuration and the first with a cost-per-kilobyte of less than US$1; the Atari ST is part of a mid-1980s generation of home computers that have 16 or 32-bit processors, 256 KB or more of RAM, mouse-controlled graphical user interfaces. This generation includes the Macintosh, Commodore Amiga, Apple IIGS, and, in certain markets, the Acorn Archimedes. "ST" stands for "Sixteen/Thirty-two", which refers to the Motorola 68000's 16-bit external bus and 32-bit internals. The ST was sold with the less expensive monochrome monitor; the system's two color graphics modes are only available on the former while the highest-resolution mode needs the monochrome monitor.
In some markets Germany, the machine gained a strong foothold as a small business machine for CAD and desktop publishing work. Thanks to its built-in MIDI ports, the ST enjoyed success for running music-sequencer software and as a controller of musical instruments among amateurs and well-known musicians alike; the ST was superseded by the Atari STE, Atari TT, Atari MEGA STE, Falcon computers. The Atari ST was born from the rivalry between home-computer makers Atari, Inc. and Commodore International. Jay Miner, one of the original designers for the custom chips found in the Atari 2600 and Atari 8-bit family, tried to convince Atari management to create a new chipset for a video game console and computer; when his idea was rejected, Miner left Atari to form a small think tank called Hi-Toro in 1982 and began designing the new "Lorraine" chipset. The company, renamed Amiga Corporation, was pretending to sell video game controllers to deceive competition while it developed a Lorraine-based computer.
Amiga ran out of capital to complete Lorraine's development, Atari, owned by Warner Communications, paid Amiga to continue development work. In return Atari received exclusive use of the Lorraine design for one year as a video game console. After one year Atari would have the right to add a keyboard and market the complete computer, designated the 1850XLD; as Atari was involved with Disney at the time, it was code-named "Mickey", the 256K memory expansion board was codenamed "Minnie". After leaving Commodore International in January 1984, Jack Tramiel formed Tramel Technology with his sons and other ex-Commodore employees and, in April, began planning a new computer; the company considered the National Semiconductor NS320xx microprocessor but was disappointed with its performance. This started the move to the 68000; the lead designer of the Atari ST was ex-Commodore employee Shiraz Shivji, who had worked on the Commodore 64's development. Atari in mid-1984 was losing about a million dollars per day.
Interested in Atari's overseas manufacturing and worldwide distribution network for his new computer, Tramiel negotiated with Warner in May and June 1984. He bought Atari's Consumer Division in July; as executives and engineers left Commodore to join Tramiel's new Atari Corporation, Commodore responded by filing lawsuits against four former engineers for theft of trade secrets. The Tramiels did not purchase the employee contracts when they bought the assets of Atari Inc. so one of their first acts was to interview Atari Inc. employees to decide whom to hire at what was a brand new company. This company was called TTL renamed to Atari Corp. At the time of the purchase of Atari Inc's assets, there were 900 employees remaining from a high point of 10,000. After the interviews 100 employees were hired to work at Atari Corp. At one point a custom sound processor called AMY was a planned component for the new ST computer design, but the chip needed more time to complete, so AMY was dropped in favor of an off-the-shelf Yamaha sound chip.
It was during this time in late July/early August that Leonard Tramiel discovered the original Amiga contract, which required Amiga Corporation to deliver the Lorraine chipset to Atari on June 30, 1984. Amiga Corp. had sought more monetary support from investors in spring 1984. Having heard rumors that Tramiel was negotiating to buy Atari, Amiga Corp. entered into discussions with Commodore. The discussions led to Commodore wanting to purchase Amiga Corporation outright, which Commodore believed would cancel any outstanding contracts, including Atari's. Instead of Amiga Corp. delivering Lorraine to Atari, Commodore delivered a check of $500,000 to Atari on Amiga's behalf, in effect returning the funds Atari invested into Amiga for the chipset. Tramiel countersued Amiga Corp. on August 13, 1984. He sought an injunction to bar Amiga from producing anything with its technology. At Commodore, the Amiga team was in limbo during the summer of 1984 because of the lawsuit. No word on the status of the chipset, the Lorraine computer, or the team's fate was known.
In the fall of 1984, Commodore informed the team that the Lorraine project was active again, the chipset was to be improved, the operating system developed, the hardware design completed. While Commodore announced the Amiga 1000 with the Lorraine chipset in July 1985, the delay gave Atari, with its ma
Grim Fandango is an adventure game, directed by Tim Schafer and published by LucasArts in 1998 for Windows. It is the first adventure game by LucasArts to use 3D computer graphics overlaid on pre-rendered static backgrounds; as with other LucasArts adventure games, the player must converse with characters and examine and use objects to solve puzzles. Grim Fandango is set in the Land of the Dead, through which departed souls, represented as calaca-like figures, travel before they reach their final destination; the story follows travel agent Manuel "Manny" Calavera as he attempts to save new arrival Mercedes "Meche" Colomar, a virtuous soul, on her journey. The game combines elements of the Aztec belief of afterlife with film noir style, with influences including The Maltese Falcon, On the Waterfront and Casablanca. Grim Fandango received praise for its art direction, it was selected for several awards and is listed as one of the greatest video games of all time. However, it was a commercial failure and contributed towards LucasArts' decision to end adventure game development and the decline of the adventure game genre.
In 2014, with help from Sony, Schafer's studio Double Fine Productions acquired the Grim Fandango license following Disney's acquisition and closure of LucasArts the previous year. On January 27, 2015, Double Fine released a remastered version of the game, featuring improved graphics, controls, an orchestrated score, directors' commentary, it was released for Windows, PlayStation 4, PlayStation Vita, OS X, Linux platforms. Mobile versions for Android and iOS devices were released on May 5, 2015. A Nintendo Switch port of the remastered version was released on November 1, 2018. Grim Fandango is an adventure game, in which the player controls Manuel "Manny" Calavera as he follows Mercedes "Meche" Colomar in the Underworld; the game uses the GrimE engine, pre-rendering static backgrounds from 3D models, while the main objects and characters are animated in 3D. Additionally, cutscenes in the game have been pre-rendered in 3D; the player controls Manny's actions with a keyboard, a joystick, or a gamepad.
Manny must collect objects that can be used with either other collectible objects, parts of the scenery, or with other people in the Land of the Dead in order to solve puzzles and progress in the game. The game lacks any type of HUD. Unlike the earlier 2D LucasArts games, the player is informed of objects or persons of interest not by text floating on the screen when the player passes a cursor over them, but instead by the fact that Manny will turn his head towards that object or person as he walks by; the player reviews the inventory of items that Manny has collected by watching him pull each item in and out of his coat jacket. Manny can engage in dialogue with other characters through conversation trees to gain hints of what needs to be done to solve the puzzles or to progress the plot; as in most LucasArts adventure games, the player can never die or otherwise get into a no-win situation. Grim Fandango takes place in the Land of the Dead, where departed souls aim to make their way to the Land of Eternal Rest.
Good deeds in life are rewarded by access to better travel packages to assist in making the journey of the soul, the best of, the Number Nine, a train that takes four minutes to reach the gate to the Ninth Underworld. Souls who did not lead a kind life are left to travel through the Land of the Dead on foot, which would take around four years; such souls lose faith in the existence of the Ninth Underworld and instead find jobs in the Land of the Dead. The travel agents of the Department of Death act as the Grim Reaper to escort the souls from the mortal world to the Land of the Dead, determine which mode of transport the soul has merited; each year on the Day of the Dead, these souls are allowed to visit their families in the Land of the Living. The souls in the Land of the Dead appear as skeletal calaca figures. Alongside them are demons that have been summoned to help with the more mundane tasks of day-to-day life, such as vehicle maintenance; the souls themselves can suffer death-within-death by being "sprouted", the result of being shot with "sproutella"-filled darts that cause flowers to grow out through the bones.
Many of the characters are Mexican and occasional Spanish words are interspersed into the English dialog, resulting in Spanglish. Many of the characters smoke, following a film noir tradition; the game is divided into each taking place on November 2 on four consecutive years. Manuel "Manny" Calavera is a travel agent at the Department of Death in the city of El Marrow, forced into his job to work off a debt "to the powers that be". Manny is frustrated with being assigned clients that must take the four-year journey and is threatened to be fired by his boss, Don Copal, if he does not come up with better clients. Manny steals a client, Mercedes "Meche" Colomar, from his co-worker Domino Hurley; the Department computers assign Meche to the four-year journey though Manny believes she should have a guaranteed spot on the "Number Nine" luxury express train due to her pureness of heart in her life. After setting Meche on her way, Manny investigates further and finds that Domino and Don have been rigging the system to deny many clients Double N tickets, hoarding them for the boss of the criminal underworld, Hector LeMans.
LeMans sells the tickets at an exorbitant price to those that can afford it. Manny recognizes that he cannot stop Hector at present and instead, with the help of his driver and speed
The TurboGrafx-16 Entertainment SuperSystem, known in Japan and France as the PC Engine, is a cartridge based home video game console manufactured and marketed by NEC Home Electronics, designed by Hudson Soft. It was released in Japan on October 30, 1987 and in the United States on August 29, 1989, it had a limited release in the United Kingdom and Spain in 1990, known as TurboGrafx and based on the American model, while the Japanese model was imported and distributed in France in 1989. It was the first console released in the 16-bit era, although it used an 8-bit CPU. Intended to compete with the Nintendo Entertainment System, it ended up competing with the Sega Genesis, on the Super Nintendo Entertainment System; the TurboGrafx-16 has an 8-bit CPU, a 16-bit video color encoder, a 16-bit video display controller. The GPUs are capable of displaying 482 colors out of 512. With dimensions of just 14 cm × 14 cm × 3.8 cm, the Japanese PC Engine is the smallest major home game console made. Games were stored in CD-ROM optical format with the TurboGrafx-CD add-on.
The TurboGrafx-16 failed to break into the North American market and sold poorly, blamed on inferior marketing. Despite the "16" in its name and the marketing of the console as a 16-bit platform, it used an 8-bit CPU, a marketing tactic, criticized by some as deceptive. Developer Doug Snook of ICOM Simulations said. However, in Japan, the PC Engine, introduced into the market at a much earlier date, was successful, where it gained strong third-party support and outsold the Famicom at its 1987 debut becoming the Super Famicom's main rival. Lots of revisions - at least 17 distinct models - were made, such as portable versions and a CD-ROM add-on. An enhanced model, the PC Engine SuperGrafx, was intended to supersede the standard PC Engine, but failed to break through and was discontinued; the entire series was succeeded by the PC-FX in 1994, only released in Japan. The TurboGrafx-16 or PC Engine was a collaborative effort between Hudson Soft, who created video game software, NEC, a major company, dominant in the Japanese personal computer market with their PC-88 and PC-98 platforms.
NEC's interest in entering the lucrative video game market coincided with Hudson's failed attempt to sell designs for then-advanced graphics chips to Nintendo. NEC lacked the vital experience in the video gaming industry so approached numerous video game studios for support, they found that, by coincidence, Hudson Soft was interested in creating their own system but needed a partner for additional cash. The two companies joined together to develop the new system; the PC Engine made its debut in the Japanese market on October 30, 1987, it was a tremendous success. By 1988 it outsold the Famicom year-on-year, putting NEC and Hudson Soft ahead of Nintendo in the market, far ahead of Sega; the console had an elegant, "eye-catching" design, it was small compared to its rivals. This, coupled with a strong software lineup and strong third-party support from high-profile developers such as Namco and Konami gave NEC the lead in the Japanese market. In 1988 NEC wanted to sell the system to the American market, directed its U.
S. operations to do so. NEC Technologies boss Keith Schaefer formed a team to test the system out. One criticism they found was the lack of enthusiasm in its name'PC Engine'; the team felt its small size was not suitable to American consumers who would prefer a larger and "futuristic" design. As a result they came up with the name'TurboGrafx-16', a name representing its graphical speed and strength, its 16-bit GPU, they completely redesigned the hardware into a large, black casing. However the redesign process was lengthy, NEC in Japan was still cautious about the system's viability in the U. S. both of which delayed the system's debut in the American market. The TurboGrafx-16 was released in the New York City and Los Angeles test market in late August 1989; this came just two weeks after Sega's Genesis test-market launch on August 14, distastrous timing for NEC as Sega of America didn't waste time redesigning the original Japanese Mega Drive system. The Genesis launch was accompanied by an ad campaign mocking NEC's claim that the TurboGrafx-16 was the first 16-bit console.
The TurboGrafx-16 was marketed as a direct competitor to the NES and early television ads touted the TG-16's superior graphics and sound. These ads featured a brief montage of the TG-16's launch titles: Blazing Lazers, China Warrior, Alien Crush, etc. Sega eclipsed the TurboGrafx-16 after its American debut. NEC's decision to pack-in Keith Courage in Alpha Zones, a Hudson Soft game unknown to western gamers, proved costly as Sega packed-in a port of the hit arcade title Altered Beast with the Genesis. NEC's American operations in Chicago were overhyped about its potential and produced 750,000 units, far above actual demand. Hudson Soft earned a lot from this as NEC paid Hudson Soft royalties for every console produced, whether sold or not. By 1990 it was clear that the system was performing poorly and was edged out by Nintendo and Sega's marketing. After seeing the TurboGrafx-16 suffer in America, NEC decided to cancel their European releases. Units for the European markets were produced, which were US models modified to run on PAL television sets, branded as TurboGrafx.
NEC sold this stock to distributors - in the United Kingdom Telegames released the TurboGrafx in 1990 in limited quantities. This model was released in
The Curse of Monkey Island
The Curse of Monkey Island is an adventure game developed and published by LucasArts, the third game in the Monkey Island series. It was released in 1997 and followed the successful games The Secret of Monkey Island and Monkey Island 2: LeChuck's Revenge; the game is the twelfth and last LucasArts game to use the SCUMM engine, extensively upgraded for its last outing before being replaced by the GrimE engine for the next game in the series, Escape from Monkey Island. The Curse of Monkey Island is the first Monkey Island game to include voice acting, has a more cartoon-ish graphic style than the earlier games; the game's story centers on Guybrush Threepwood, a wannabe pirate who must lift a curse from his love Elaine Marley. As the story progresses, he must deal with a band of mysterious pirates, a rival stereotypical French buccaneer, a band of cutthroat smugglers, as well as his old nemesis LeChuck; the Curse of Monkey Island is a point-and-click adventure game. The SCUMM engine was used in this Monkey Island installment but it was upgraded to a "verb coin", an interface that consisted in a coin-shaped menu with three icons: a hand, a skull, a parrot representing actions related to hands and mouth, respectively.
These icons implied. The hand icon would mean actions such as picking something up, operating a mechanism or hitting someone, the skull icon was most used for examining or looking at objects and the parrot icon was used to issue Guybrush commands such as talking to someone or opening a bottle with his teeth; the inventory and actions were thus visible on click, rather than on the bottom of the screen as previous point-and-click games by Lucasarts. The player controlled a white'X' cursor with the mouse, that turned red whenever landing onto an object with which Guybrush could interact. Holding left click over an object, whether in or outside the inventory, would bring up the coin menu, while right clicking it would perform the most obvious action with this particular object. Right clicking a door, for example, made Guybrush attempt to open it, while right clicking a person meant talking to him or her. Guybrush Threepwood is adrift in the sea in a floating bumper car, unable to recall how he escaped from the Big Whoop amusement park.
He approaches Plunder Island, governed by his love Elaine Marley and under siege by the zombie pirate LeChuck. LeChuck locks him in the ship's hold. Seeking a way out, Guybrush fires an unrestrained cannon, finds a diamond ring in the treasure hold, escapes the ship as it sinks, he proposes to her with the diamond ring. However, the ring is revealed to be cursed, when Elaine puts it on she is transformed into a gold statue and stolen by marauders; the Voodoo Lady tells Guybrush he must travel to Blood Island to find a diamond ring of greater value to break the spell. Guybrush recovers the statue Elaine, finds a map to Blood Island and secures a ship and crew to take him there. On the journey, the ship is attacked by Captain Rottingham. After much practice, Guybrush learns seabattle insult swordfighting and defeats Rottingham when they next meet, reclaiming the map. However, soon afterwards, Guybrush's ship crashes on Blood Island in a storm, Elaine's statue is launched inland, the crew mutinies.
Meanwhile, LeChuck is inadvertently revived as a pyrokinetic demon-pirate by a scavenging pirate, sails back to his carnival on Monkey Island to organize the capture of Guybrush and Elaine. Alone on Blood Island, Guybrush meets the locals, including the cannibals of Monkey Island, learns a sad tale of lost love, feigns death to enter a crypt and secure a new engagement band, he gambles with smugglers in order to acquire an uncursed diamond, combines the two to make a new ring, returns Elaine to normal. The two share a moment. LeChuck transforms Guybrush into a child once again and leaves him in the Big Whoop amusement park with Elaine. Using a hangover cure discovered on Blood Island, Guybrush becomes an adult again and gets on the Rollercoaster of Death to confront LeChuck. Guybrush improvises an sets off an avalanche, burying LeChuck under the theme park. Guybrush and Elaine marry and set sail for their honeymoon, as various friends that were met on his adventures wave them goodbye; the Curse of Monkey Island was announced during the European Computer Trade Show in September 1996.
According to Next Generation, the game's predecessors had been "relatively minor hit" in the United States, but became "blockbusters on the PC and the Amiga throughout Europe." Monkey Island creator Ron Gilbert had parted ways with the series after Monkey Island 2, the new project leaders were Jonathan Ackley and Larry Ahern, both of whom had worked on Full Throttle. The lead background artist was Bill Tiller. During production, examples of major changes include enhancing the role of Murray, the talking skull. Intended only to be featured in the first chapter, he proved so popular with test players that he was written to re-appear at several points in the game; the game was re-released on a CD-ROM compilation of Monkey Island games, bundled with The Secret of Monkey Island and Monkey Island 2: LeChuck's Revenge called the Monkey Island Bounty Pack. After the game shipped, a Monkey Island film was in the works; this was only brought to light when Tony Stacchi, a concept artist for the project, sent his work to The Scumm Bar, a Monkey Island fansite.
The film was cancelled in the early stages o
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri
In computing, multitasking is the concurrent execution of multiple tasks over a certain period of time. New tasks can interrupt started ones before they finish, instead of waiting for them to end; as a result, a computer executes segments of multiple tasks in an interleaved manner, while the tasks share common processing resources such as central processing units and main memory. Multitasking automatically interrupts the running program, saving its state and loading the saved state of another program and transferring control to it; this "context switch" may be initiated at fixed time intervals, or the running program may be coded to signal to the supervisory software when it can be interrupted. Multitasking does not require parallel execution of multiple tasks at the same time. On multiprocessor computers, multitasking allows many more tasks to be run than there are CPUs. Multitasking is a common feature of computer operating systems, it allows more efficient use of the computer hardware. In a time sharing system, multiple human operators use the same processor as if it was dedicated to their use, while behind the scenes the computer is serving many users by multitasking their individual programs.
In multiprogramming systems, a task runs until it must wait for an external event or until the operating system's scheduler forcibly swaps the running task out of the CPU. Real-time systems such as those designed to control industrial robots, require timely processing. Multitasking operating systems include measures to change the priority of individual tasks, so that important jobs receive more processor time than those considered less significant. Depending on the operating system, a task might be as large as an entire application program, or might be made up of smaller threads that carry out portions of the overall program. A processor intended for use with multitasking operating systems may include special hardware to securely support multiple tasks, such as memory protection, protection rings that ensure the supervisory software cannot be damaged or subverted by user-mode program errors; the term "multitasking" has become an international term, as the same word is used in many other languages such as German, Dutch and Norwegian.
In the early days of computing, CPU time was expensive, peripherals were slow. When the computer ran a program that needed access to a peripheral, the central processing unit would have to stop executing program instructions while the peripheral processed the data; this was very inefficient. The first computer using a multiprogramming system was the British Leo III owned by J. Co.. During batch processing, several different programs were loaded in the computer memory, the first one began to run; when the first program reached an instruction waiting for a peripheral, the context of this program was stored away, the second program in memory was given a chance to run. The process continued; the use of multiprogramming was enhanced by the arrival of virtual memory and virtual machine technology, which enabled individual programs to make use of memory and operating system resources as if other concurrently running programs were, for all practical purposes, non-existent and invisible to them. Multiprogramming doesn't give any guarantee.
Indeed, the first program may well run for hours without needing access to a peripheral. As there were no users waiting at an interactive terminal, this was no problem: users handed in a deck of punched cards to an operator, came back a few hours for printed results. Multiprogramming reduced wait times when multiple batches were being processed. Early multitasking systems used applications; this approach, supported by many computer operating systems, is known today as cooperative multitasking. Although it is now used in larger systems except for specific applications such as CICS or the JES2 subsystem, cooperative multitasking was once the only scheduling scheme employed by Microsoft Windows and Classic Mac OS to enable multiple applications to run simultaneously. Cooperative multitasking is still used today on RISC OS systems; as a cooperatively multitasked system relies on each process giving up time to other processes on the system, one poorly designed program can consume all of the CPU time for itself, either by performing extensive calculations or by busy waiting.
In a server environment, this is a hazard. Preemptive multitasking allows the computer system to more reliably guarantee to each process a regular "slice" of operating time, it allows the system to deal with important external events like incoming data, which might require the immediate attention of one or another process. Operating systems were developed to take advantage of these hardware capabilities and run multiple processes preemptively. Preemptive multitasking was implemented in the PDP-6 Monitor and MULTICS in 1964, in OS/360 MFT in 1967, in Unix in 1969, was available in some operating systems for computers as small as DEC's PDP-8.