In computing , an emulator is hardware or software that enables one computer system (called the host ) to behave like another computer system (called the guest ). An emulator typically enables the host system to run software or use peripheral devices designed for the guest system. Emulation refers to the ability of a computer program in an electronic device to emulate (or imitate) another program or device.
139-423: Many printers , for example, are designed to emulate HP LaserJet printers because so much software is written for HP printers. If a non-HP printer emulates an HP printer, any software written for a real HP printer will also run in the non-HP printer emulation and produce equivalent printing. Since at least the 1990s, many video game enthusiasts and hobbyists have used emulators to play classic arcade games from
278-453: A digital preservation strategy states, "the ideal approach would provide a single extensible , long-term solution that can be designed once and for all and applied uniformly, automatically, and in organized synchrony (for example, at every refresh cycle) to all types of documents and media". He further states that this should not only apply to out of date systems, but also be upwardly mobile to future unknown systems. Practically speaking, when
417-467: A network and can print at speeds of 45 to around 100 ppm. The Xerox 9700 could achieve 120 ppm. An ID Card printer is used for printing plastic ID cards. These can now be customised with important features such as holographic overlays, HoloKotes and watermarks. This is either a direct to card printer (the more feasible option) or a retransfer printer. A virtual printer is a piece of computer software whose user interface and API resembles that of
556-454: A typewriter ), or, less commonly, hits the back of the paper, pressing the paper against the ink ribbon (the IBM 1403 for example). All but the dot matrix printer rely on the use of fully formed characters , letterforms that represent each of the characters that the printer was capable of printing. In addition, most of these printers were limited to monochrome, or sometimes two-color, printing in
695-406: A typewriter . A hammer strikes a wheel with petals, the "daisy wheel", each petal containing a letter form at its tip. The letter form strikes a ribbon of ink , depositing the ink on the page and thus printing a character. By rotating the daisy wheel, different characters are selected for printing. These printers were also referred to as letter-quality printers because they could produce text which
834-486: A xerographic printing process but differ from analog photocopiers in that the image is produced by the direct scanning of a laser beam across the printer's photoreceptor . Another toner-based printer is the LED printer which uses an array of LEDs instead of a laser to cause toner adhesion to the print drum. Inkjet printers operate by propelling variably sized droplets of liquid ink onto almost any sized page. They are
973-589: A "control program", but the terms " hypervisor " or "virtual machine monitor" became preferred over time. Each hypervisor can manage or run multiple virtual machines . Printer (computing) In computing , a printer is a peripheral machine which makes a durable representation of graphics or text, usually on paper . While most output is human-readable, bar code printers are an example of an expanded use for printers. Different types of printers include 3D printers, inkjet printers, laser printers, and thermal printers. The first computer printer designed
1112-562: A National Agenda for Simulation-Based Medical Education (Eder-Van Hook, Jackie, 2004), "a health care provider's ability to react prudently in an unexpected situation is one of the most critical factors in creating a positive outcome in medical emergency, regardless of whether it occurs on the battlefield, freeway, or hospital emergency room." Eder-Van Hook (2004) also noted that medical errors kill up to 98,000 with an estimated cost between $ 37 and $ 50 million and $ 17 to $ 29 billion for preventable adverse events dollars per year. Simulation
1251-524: A [Commodore] 64 to emulate an IBM PC [which uses MS-DOS], in the same sense that it's possible to bail out Lake Michigan with a teaspoon . Most emulators just emulate a hardware architecture—if operating system firmware or software is required for the desired software, it must be provided as well (and may itself be emulated). Both the OS and the software will then be interpreted by the emulator, rather than being run by native hardware. Apart from this interpreter for
1390-415: A brochure. As of the 2020s, 3D printing has become a widespread hobby due to the abundance of cheap 3D printer kits, with the most common process being Fused deposition modeling . Personal printers are mainly designed to support individual users, and may be connected to only a single computer. These printers are designed for low-volume, short-turnaround print jobs , requiring minimal setup time to produce
1529-523: A certain application is released in a new version, rather than address compatibility issues and migration for every digital object created in the previous version of that application , one could create an emulator for the application , allowing access to all of said digital objects. Because of its primary use of digital formats, new media art relies heavily on emulation as a preservation strategy. Artists such as Cory Arcangel specialize in resurrecting obsolete technologies in their artwork and recognize
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#17328518784991668-407: A chemical coated paper, which is charged by the print head according to the image of the document. The paper is passed near a pool of liquid ink with the opposite charge. The charged areas of the paper attract the ink and thus form the image. This process was developed from the process of electrostatic copying . Color reproduction is very accurate, and because there is no heating the scale distortion
1807-445: A cheque must be printed using MICR toner or ink. Banks and other clearing houses employ automation equipment that relies on the magnetic flux from these specially printed characters to function properly. The following printing technologies are routinely found in modern printers: A laser printer rapidly produces high quality text and graphics. As with digital photocopiers and multifunction printers (MFPs), laser printers employ
1946-480: A closer connection to the authenticity of the digital object, operating system, or even gaming platform. Emulation addresses the original hardware and software environment of the digital object, and recreates it on a current machine. The emulator allows the user to have access to any kind of application or operating system on a current platform , while the software runs as it did in its original environment. Jeffery Rothenberg, an early proponent of emulation as
2085-444: A company does not already have a local (or network) printer that has the features they need, then the web-based option is a perhaps a more affordable solution. The web-based solution is good for small businesses that do not anticipate a lot of rapid growth, or organizations who either can not afford a card printer, or do not have the resources to learn how to set up and use one. Generally speaking, desktop-based solutions involve software,
2224-495: A computer connected to a plastic simulation of the relevant anatomy. Sophisticated simulators of this type employ a life-size mannequin that responds to injected drugs and can be programmed to create simulations of life-threatening emergencies. In other simulations, visual components of the procedure are reproduced by computer graphics techniques, while touch-based components are reproduced by haptic feedback devices combined with physical simulation routines computed in response to
2363-645: A considerable increase in durability and a greater degree of counterfeit prevention. Some card printers come with an option to print both sides at the same time, which cuts down the time taken to print and less margin of error. In such printers one side of id card is printed and then the card is flipped in the flip station and other side is printed. Alongside the traditional uses in time attendance and access control (in particular with photo personalization), countless other applications have been found for plastic cards, e.g. for personalized customer and members' cards, for sports ticketing and in local public transport systems for
2502-449: A database (or spreadsheet) and can be installed on a single computer or network. Alongside the basic function of printing cards, card printers can also read and encode magnetic stripes as well as contact and contact free RFID chip cards ( smart cards ). Thus card printers enable the encoding of plastic cards both visually and logically. Plastic cards can also be laminated after printing. Plastic cards are laminated after printing to achieve
2641-509: A dedicated data cable such as the USB , through a short-range radio like Bluetooth , a local area network using cables (such as the Ethernet ) or radio (such as WiFi ), or on a standalone basis without a computer, using a memory card or other portable data storage device. Simulation#Computer science A simulation is an imitative representation of a process or system that could exist in
2780-466: A detailed description of many of the technologies used. Several different computer printers were simply computer-controllable versions of existing electric typewriters. The Friden Flexowriter and IBM Selectric-based printers were the most-common examples. The Flexowriter printed with a conventional typebar mechanism while the Selectric used IBM's well-known "golf ball" printing mechanism. In either case,
2919-555: A digital circuit such as a processor. This is done after a digital circuit has been designed in logic equations, but before the circuit is fabricated in hardware. Functional simulation is the use of a computer program to simulate the execution of a second computer program written in symbolic assembly language or compiler language, rather than in binary machine code . By using a functional simulator, programmers can execute and trace selected sections of source code to search for programming errors (bugs), without generating binary code. This
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#17328518784993058-469: A great deal of promise for virtual simulations. Systems such as brain–computer interfaces (BCIs) offer the ability to further increase the level of immersion for virtual simulation users. Lee, Keinrath, Scherer, Bischof, Pfurtscheller proved that naïve subjects could be trained to use a BCI to navigate a virtual apartment with relative ease. Using the BCI, the authors found that subjects were able to freely navigate
3197-443: A hard copy of a given document. They are generally slow devices ranging from 6 to around 25 pages per minute (ppm), and the cost per page is relatively high. However, this is offset by the on-demand convenience. Some printers can print documents stored on memory cards or from digital cameras and scanners . Networked or shared printers are "designed for high-volume, high-speed printing". They are usually shared by many users on
3336-405: A hardware or microcode assist, while "simulation" referred to pure software emulation. For example, a computer specially built for running programs designed for another architecture is an emulator. In contrast, a simulator could be a program which runs on a PC, so that old Atari games can be simulated on it. Purists continue to insist on this distinction, but currently the term "emulation" often means
3475-527: A layer of ink on paper. A card printer is an electronic desktop printer with single card feeders which print and personalize plastic cards . In this respect they differ from, for example, label printers which have a continuous supply feed. Card dimensions are usually 85.60 × 53.98 mm, standardized under ISO/IEC 7810 as ID-1. This format is also used in EC-cards , telephone cards , credit cards , driver's licenses and health insurance cards . This
3614-497: A model in which a complete enumeration of all possible states would be prohibitive or impossible. Several software packages exist for running computer-based simulation modeling (e.g. Monte Carlo simulation, stochastic modeling, multimethod modeling) that makes all the modeling almost effortless. Modern usage of the term "computer simulation" may encompass virtually any computer-based representation. In computer science , simulation has some specialized meanings: Alan Turing used
3753-399: A more systematic view of the concept. Physical simulation refers to simulation in which physical objects are substituted for the real thing (some circles use the term for computer simulations modelling selected laws of physics, but this article does not). These physical objects are often chosen because they are smaller or cheaper than the actual object or system. Interactive simulation
3892-537: A period during the early home computer era when a range of printers were manufactured under many brands such as the Commodore VIC-1525 using the Seikosha Uni-Hammer system. This used a single solenoid with an oblique striker that would be actuated 7 times for each column of 7 vertical pixels while the head was moving at a constant speed. The angle of the striker would align the dots vertically even though
4031-593: A printer driver, but which is not connected with a physical computer printer. A virtual printer can be used to create a file which is an image of the data which would be printed, for archival purposes or as input to another program, for example to create a PDF or to transmit to another system or user. A barcode printer is a computer peripheral for printing barcode labels or tags that can be attached to, or printed directly on, physical objects. Barcode printers are commonly used to label cartons before shipment, or to label retail items with UPCs or EANs . A 3D printer
4170-468: A printer on their network that is capable of printing identification cards. If a business already owns an ID card printer, then a desktop-based badge maker is probably suitable for their needs. Typically, large organizations who have high employee turnover will have their own printer. A desktop-based badge maker is also required if a company needs their IDs make instantly. An example of this is the private construction site that has restricted access. However, if
4309-420: A problem when emulating computers whose processor speed is on the same order of magnitude as the host machine. Until not many years ago, emulation in such situations was considered completely impractical by many. What allowed breaking through this restriction were the advances in dynamic recompilation techniques. Simple a priori translation of emulated program code into code runnable on the host architecture
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4448-400: A safety-critical system. Simulations in education are somewhat like training simulations. They focus on specific tasks. The term 'microworld' is used to refer to educational simulations which model some abstract concept rather than simulating a realistic object or environment, or in some cases model a real-world environment in a simplistic way so as to help a learner develop an understanding of
4587-538: A service is where simulation is accessed as a service over the web. Modeling, interoperable simulation and serious games is where serious game approaches (e.g. game engines and engagement methods) are integrated with interoperable simulation. Simulation fidelity is used to describe the accuracy of a simulation and how closely it imitates the real-life counterpart. Fidelity is broadly classified as one of three categories: low, medium, and high. Specific descriptions of fidelity levels are subject to interpretation, but
4726-449: A simulation of an epidemic could change the number of infected people at time instants when susceptible individuals get infected or when infected individuals recover. Stochastic simulation is a simulation where some variable or process is subject to random variations and is projected using Monte Carlo techniques using pseudo-random numbers. Thus replicated runs with the same boundary conditions will each produce different results within
4865-404: A simulator—although, perhaps, denoting a slightly different meaning of simulator —is the use of a placebo drug, a formulation that simulates the active drug in trials of drug efficacy. Patient safety is a concern in the medical industry. Patients have been known to suffer injuries and even death due to management error, and lack of using best standards of care and training. According to Building
5004-402: A single horizontal series of pixels across the page), referring to the configuration of the print head. In the 1970s and '80s, dot matrix printers were one of the more common types of printers used for general use, such as for home and small office use. Such printers normally had either 9 or 24 pins on the print head (early 7 pin printers also existed, which did not print descenders ). There was
5143-501: A single typeface at one time, although bolding and underlining of text could be done by "overstriking", that is, printing two or more impressions either in the same character position or slightly offset. Impact printers varieties include typewriter-derived printers, teletypewriter-derived printers, daisywheel printers, dot matrix printers, and line printers. Dot-matrix printers remain in common use in businesses where multi-part forms are printed. An overview of impact printing contains
5282-403: A software implementation. Even in emulators that treat each device as a special case, there is usually a common basic infrastructure for: Emulation is one strategy in pursuit of digital preservation and combating obsolescence . Emulation focuses on recreating an original computer environment, which can be time-consuming and difficult to achieve, but valuable because of its ability to maintain
5421-405: A specific confidence band. Deterministic simulation is a simulation which is not stochastic: thus the variables are regulated by deterministic algorithms. So replicated runs from the same boundary conditions always produce identical results. Hybrid simulation (or combined simulation) corresponds to a mix between continuous and discrete event simulation and results in integrating numerically
5560-405: A specific machine. The simplest form of a CPU simulator is an interpreter , which is a computer program that follows the execution flow of the emulated program code and, for every machine code instruction encountered, executes operations on the host processor that are semantically equivalent to the original instructions. This is made possible by assigning a variable to each register and flag of
5699-471: A standard, unified I/O API can, however, rival such simpler models, if well thought-out, and they have the additional advantage of "automatically" providing a plug-in service through which third-party virtual devices can be used within the emulator. A unified I/O API may not necessarily mirror the structure of the real hardware bus: bus design is limited by several electric constraints and a need for hardware concurrency management that can mostly be ignored in
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5838-432: A virtual power source, this would be a highly unusual solution. Emulators typically stop at a simulation of the documented hardware specifications and digital logic. Sufficient emulation of some hardware platforms requires extreme accuracy, down to the level of individual clock cycles, undocumented features, unpredictable analog elements, and implementation bugs. This is particularly the case with classic home computers such as
5977-438: Is Distributed Interactive Simulation (DIS). Parallel simulation speeds up a simulation's execution by concurrently distributing its workload over multiple processors, as in high-performance computing . Interoperable simulation is where multiple models, simulators (often defined as federates) interoperate locally, distributed over a network; a classical example is High-Level Architecture . Modeling and simulation as
6116-403: Is Zink (a portmanteau of "zero ink"). The following technologies are either obsolete, or limited to special applications though most were, at one time, in widespread use. Impact printers rely on a forcible impact to transfer ink to the media. The impact printer uses a print head that either hits the surface of the ink ribbon, pressing the ink ribbon against the paper (similar to the action of
6255-406: Is a device for making a three-dimensional object from a 3D model or other electronic data source through additive processes in which successive layers of material (including plastics, metals, food, cement, wood, and other materials) are laid down under computer control. It is called a printer by analogy with an inkjet printer which produces a two-dimensional document by a similar process of depositing
6394-512: Is a special kind of physical simulation, often referred to as a human-in-the-loop simulation, in which physical simulations include human operators, such as in a flight simulator , sailing simulator , or driving simulator . Continuous simulation is a simulation based on continuous-time rather than discrete-time steps, using numerical integration of differential equations . Discrete-event simulation studies systems whose states change their values only at discrete times. For example,
6533-464: Is also good evidence that procedural simulation improves actual operational performance in clinical settings." However, there is a need to have improved evidence to show that crew resource management training through simulation. One of the largest challenges is showing that team simulation improves team operational performance at the bedside. Although evidence that simulation-based training actually improves patient outcome has been slow to accrue, today
6672-568: Is an attempt to model a real-life or hypothetical situation on a computer so that it can be studied to see how the system works. By changing variables in the simulation, predictions may be made about the behaviour of the system. It is a tool to virtually investigate the behaviour of the system under study. Computer simulation has become a useful part of modeling many natural systems in physics , chemistry and biology , and human systems in economics and social science (e.g., computational sociology ) as well as in engineering to gain insight into
6811-404: Is being used to study patient safety, as well as train medical professionals. Studying patient safety and safety interventions in healthcare is challenging, because there is a lack of experimental control (i.e., patient complexity, system/process variances) to see if an intervention made a meaningful difference (Groves & Manges, 2017). An example of innovative simulation to study patient safety
6950-561: Is commonly known as the bank card format. Card printers are controlled by corresponding printer drivers or by means of a specific programming language. Generally card printers are designed with laminating, striping, and punching functions, and use desktop or web-based software. The hardware features of a card printer differentiate a card printer from the more traditional printers, as ID cards are usually made of PVC plastic and require laminating and punching. Different card printers can accept different card thickness and dimensions. The principle
7089-466: Is directly available to the programmer, and the speed and execution of the simulation can be varied at will. Simulators may also be used to interpret fault trees , or test VLSI logic designs before they are constructed. Symbolic simulation uses variables to stand for unknown values. In the field of optimization , simulations of physical processes are often used in conjunction with evolutionary computation to optimize control strategies. Simulation
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#17328518784997228-468: Is distinct from simulating execution of binary code, which is software emulation. The first functional simulator was written by Autonetics about 1960 for testing assembly language programs for later execution in military computer D-17B . This made it possible for flight programs to be written, executed, and tested before D-17B computer hardware had been built. Autonetics also programmed a functional simulator for testing flight programs for later execution in
7367-562: Is divided into modules that correspond roughly to the emulated computer's subsystems. Most often, an emulator will be composed of the following modules: Buses are often not emulated, either for reasons of performance or simplicity, and virtual peripherals communicate directly with the CPU or the memory subsystem. It is possible for the memory subsystem emulation to be reduced to simply an array of elements each sized like an emulated word; however, this model fails very quickly as soon as any location in
7506-414: Is extensively used for educational purposes. It is used for cases where it is prohibitively expensive or simply too dangerous to allow trainees to use the real equipment in the real world. In such situations they will spend time learning valuable lessons in a "safe" virtual environment yet living a lifelike experience (or at least it is the goal). Often the convenience is to permit mistakes during training for
7645-428: Is from nursing research. Groves et al. (2016) used a high-fidelity simulation to examine nursing safety-oriented behaviors during times such as change-of-shift report . However, the value of simulation interventions to translating to clinical practice are is still debatable. As Nishisaki states, "there is good evidence that simulation training improves provider and team self-efficacy and competence on manikins. There
7784-405: Is important for such applications to be properly emulated. Most emulators do not, as mentioned earlier, emulate the main system bus ; each I/O device is thus often treated as a special case, and no consistent interface for virtual peripherals is provided. This can result in a performance advantage, since each I/O module can be tailored to the characteristics of the emulated device; designs based on
7923-413: Is kept in a code cache , and the original code is not lost or affected; this way, even data segments can be (meaninglessly) translated by the recompiler, resulting in no more than a waste of translation time. Speed may not be desirable as some older games were not designed with the speed of faster computers in mind. A game designed for a 30 MHz PC with a level timer of 300 game seconds might only give
8062-606: Is less than ±0.1%. (All laser printers have an accuracy of ±1%.) Worldwide, most survey offices used this printer before color inkjet plotters become popular. Liquid ink electrostatic printers were mostly available in 36 to 54 inches (910 to 1,370 mm) width and also 6 color printing. These were also used to print large billboards. It was first introduced by Versatec, which was later bought by Xerox . 3M also used to make these printers. Pen-based plotters were an alternate printing technology once common in engineering and architectural firms. Pen-based plotters rely on contact with
8201-413: Is no longer available), or in a tightly controlled testing environment (see Computer architecture simulator and Platform virtualization ). For example, simulators have been used to debug a microprogram or sometimes commercial application programs, before the program is downloaded to the target machine. Since the operation of the computer is simulated, all of the information about the computer's operation
8340-474: Is often forgotten is resistance to alteration: liquid ink , such as from an inkjet head or fabric ribbon, becomes absorbed by the paper fibers, so documents printed with liquid ink are more difficult to alter than documents printed with toner or solid inks, which do not penetrate below the paper surface. Cheques can be printed with liquid ink or on special cheque paper with toner anchorage so that alterations may be detected. The machine-readable lower portion of
8479-461: Is patient care to deliver just-in-time service or/and just-in-place. This training consists of 20 minutes of simulated training just before workers report to shift. One study found that just in time training improved the transition to the bedside. The conclusion as reported in Nishisaki (2008) work, was that the simulation training improved resident participation in real cases; but did not sacrifice
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#17328518784998618-445: Is rare in real emulators for performance reasons (it is generally faster to use a subroutine to do the work of an interrupt). Interpreters are very popular as computer simulators, as they are much simpler to implement than more time-efficient alternative solutions, and their speed is more than adequate for emulating computers of more than roughly a decade ago on modern machines. However, the speed penalty inherent in interpretation can be
8757-404: Is the virtualization of computers as complete hardware platforms, certain logical abstractions of their components, or only the functionality required to run various operating systems . Virtualization hides the physical characteristics of a computing platform from the users, presenting instead an abstract computing platform. At its origins, the software that controlled virtualization was called
8896-506: Is the same for practically all card printers: the plastic card is passed through a thermal print head at the same time as a color ribbon. The color from the ribbon is transferred onto the card through the heat given out from the print head. The standard performance for card printing is 300 dpi (300 dots per inch, equivalent to 11.8 dots per mm). There are different printing processes, which vary in their detail: Broadly speaking there are three main types of card printers, differing mainly by
9035-492: Is these procedures' duty to map every access to the correct location of the correct object. On a base-limit addressing system where memory from address 0 to address ROMSIZE-1 is read-only memory, while the rest is RAM, something along the line of the following procedures would be typical: The CPU simulator is often the most complicated part of an emulator. Many emulators are written using "pre-packaged" CPU simulators, in order to concentrate on good and efficient emulation of
9174-402: Is usually impossible because of several reasons: Various forms of dynamic recompilation, including the popular Just In Time compiler (JIT) technique, try to circumvent these problems by waiting until the processor control flow jumps into a location containing untranslated code, and only then ("just in time") translates a block of the code into host code that can be executed. The translated code
9313-449: The 650 on the 705 . In addition to simulators, IBM had compatibility features on the 709 and 7090 , for which it provided the IBM 709 computer with a program to run legacy programs written for the IBM 704 on the 709 and later on the IBM 7090. This program used the instructions added by the compatibility feature to trap instructions requiring special handling; all other 704 instructions ran
9452-527: The Commodore 64 , whose software often depends on highly sophisticated low-level programming tricks invented by game programmers and the " demoscene ". In contrast, some other platforms have had very little use of direct hardware addressing, such as an emulator for the PlayStation 4. In these cases, a simple compatibility layer may suffice. This translates system calls for the foreign system into system calls for
9591-477: The Game Boy Advance , saw significant progress toward emulation during their production. This led to an effort by console manufacturers to stop unofficial emulation, but consistent failures such as Sega v. Accolade 977 F.2d 1510 (9th Cir. 1992), Sony Computer Entertainment, Inc. v. Connectix Corporation 203 F.3d 596 (2000), and Sony Computer Entertainment America v. Bleem 214 F.3d 1022 (2000), have had
9730-511: The IBM 3270 or VT100 and many others are no longer produced as physical devices. Instead, software running on modern operating systems simulates a "dumb" terminal and is able to render the graphical and text elements of the host application, send keystrokes and process commands using the appropriate terminal protocol. Some terminal emulation applications include Attachmate Reflection , IBM Personal Communications , and Micro Focus Rumba. Other types of emulators include: Typically, an emulator
9869-878: The 1980s using the games' original 1980s machine code and data, which is interpreted by a current-era system, and to emulate old video game consoles (see video game console emulator ). A hardware emulator is an emulator which takes the form of a hardware device. Examples include the DOS-compatible card installed in some 1990s-era Macintosh computers, such as the Centris 610 or Performa 630 , that allowed them to run personal computer (PC) software programs and field-programmable gate array -based hardware emulators . The Church-Turing thesis implies that theoretically, any operating environment can be emulated within any other environment, assuming memory limitations are ignored. However, in practice, it can be quite difficult, particularly when
10008-401: The 1990s and into the 2000s has largely displaced the need for printing as a means of moving documents, and a wide variety of reliable storage systems means that a "physical backup" is of little benefit today. Starting around 2010, 3D printing became an area of intense interest, allowing the creation of physical objects with the same sort of effort as an early laser printer required to produce
10147-409: The CPU may slow the system down. If a math coprocessor is not installed or present on the CPU, when the CPU executes any co-processor instruction it will make a determined interrupt (coprocessor not available), calling the math emulator routines. When the instruction is successfully emulated, the program continues executing. Logic simulation is the use of a computer program to simulate the operation of
10286-508: The Past series of historical educational games. The National Science Foundation has also supported the creation of reacting games that address science and math education. In social media simulations, participants train communication with critics and other stakeholders in a private environment. In recent years, there has been increasing use of social simulations for staff training in aid and development agencies. The Carana simulation, for example,
10425-452: The X- and Y-axes, by a mechanism, and the selected letter form was struck by a hammer. Others used a type cylinder in a similar way as the Selectric typewriters used their type ball. In either case, the letter form then struck a ribbon to print the letterform. Most teleprinters operated at ten characters per second although a few achieved 15 CPS. Daisy wheel printers operate in much the same fashion as
10564-567: The Xbox 360, Xbox One, Nintendo 3DS, etc. Generally such emulators make currently impossible claims such as being able to run Xbox One and Xbox 360 games in a single program. As computers and global computer networks continued to advance and emulator developers grew more skilled in their work, the length of time between the commercial release of a console and its successful emulation began to shrink. Fifth generation consoles such as Nintendo 64 , PlayStation and sixth generation handhelds, such as
10703-415: The ability of simulation to provide hands-on experience that translates to the operating room is no longer in doubt. One of the largest factors that might impact the ability to have training impact the work of practitioners at the bedside is the ability to empower frontline staff (Stewart, Manges, Ward, 2015). Another example of an attempt to improve patient safety through the use of simulations training
10842-424: The art and science of project management. Using simulation for project management training improves learning retention and enhances the learning process. Social simulations may be used in social science classrooms to illustrate social and political processes in anthropology, economics, history, political science, or sociology courses, typically at the high school or university level. These may, for example, take
10981-402: The commands received from the CPU as the original program would. Developers of software for embedded systems or video game consoles often design their software on especially accurate emulators called simulators before trying it on the real hardware. This is so that software can be produced and tested before the final hardware exists in large quantities, so that it can be tested without taking
11120-496: The complete imitation of a machine executing binary code while "simulation" often refers to computer simulation , where a computer program is used to simulate an abstract model. Computer simulation is used in virtually every scientific and engineering domain and Computer Science is no exception, with several projects simulating abstract models of computer systems, such as network simulation , which both practically and semantically differs from network emulation. Hardware virtualization
11259-455: The computer's logical memory does not match physical memory . This clearly is the case whenever the emulated hardware allows for advanced memory management (in which case, the MMU logic can be embedded in the memory emulator, made a module of its own, or sometimes integrated into the CPU simulator). Even if the emulated computer does not feature an MMU, though, there are usually other factors that break
11398-409: The design and development of new systems. It eases the development process by providing the ability to detect, recreate and repair flaws in the design even before the system is actually built. It is particularly useful in the design of multi-core systems, where concurrency errors can be very difficult to detect and correct without the controlled environment provided by virtual hardware. This also allows
11537-410: The development of new systems specifically for computer use. In the 1980s there were daisy wheel systems similar to typewriters, line printers that produced similar output but at much higher speed, and dot-matrix systems that could mix text and graphics but produced relatively low-quality output. The plotter was used for those requiring high-quality line art like blueprints . The introduction of
11676-582: The development process of "home brew" DIY demos and in the creation of new games for older systems. The Internet has helped in the spread of console emulators, as most - if not all - would be unavailable for sale in retail outlets. Examples of console emulators that have been released in the last few decades are: RPCS3 , Dolphin , Cemu , PCSX2 , PPSSPP , ZSNES , Citra , ePSXe , Project64 , Visual Boy Advance , Nestopia , and Yuzu . Due to their popularity, emulators have been impersonated by malware. Most of these emulators are for video game consoles like
11815-418: The differential equations between two sequential events to reduce the number of discontinuities. A stand-alone simulation is a simulation running on a single workstation by itself. A distributed simulation is one which uses more than one computer simultaneously, to guarantee access from/to different resources (e.g. multi-users operating different systems, or distributed data sets); a classical example
11954-418: The emulated binary machine's language , some other hardware (such as input or output devices) must be provided in virtual form as well; for example, if writing to a specific memory location should influence what is displayed on the screen, then this would need to be emulated. While emulation could, if taken to the extreme, go down to the atomic level, basing its output on a simulation of the actual circuitry from
12093-401: The end of the twentieth century. Line printers print an entire line of text at a time. Four principal designs exist. In each case, to print a line, precisely timed hammers strike against the back of the paper at the exact moment that the correct character to be printed is passing in front of the paper. The paper presses forward against a ribbon which then presses against the character form and
12232-505: The equivalence between logical and physical memory: many (if not most) architectures offer memory-mapped I/O ; even those that do not often have a block of logical memory mapped to ROM , which means that the memory-array module must be discarded if the read-only nature of ROM is to be emulated. Features such as bank switching or segmentation may also complicate memory emulation. As a result, most emulators implement at least two procedures for writing to and reading from logical memory, and it
12371-472: The eventual real effects of alternative conditions and courses of action. Simulation is also used when the real system cannot be engaged, because it may not be accessible, or it may be dangerous or unacceptable to engage, or it is being designed but not yet built, or it may simply not exist. Key issues in modeling and simulation include the acquisition of valid sources of information about the relevant selection of key characteristics and behaviors used to build
12510-433: The exact behavior of the system to be emulated is not documented and has to be deduced through reverse engineering . It also says nothing about timing constraints; if the emulator does not perform as quickly as it did using the original hardware, the software inside the emulation may run much more slowly (possibly triggering timer interrupts that alter behavior). "Can a Commodore 64 emulate MS-DOS ?" Yes, it's possible for
12649-399: The following generalizations can be made: A synthetic environment is a computer simulation that can be included in human-in-the-loop simulations. Simulation in failure analysis refers to simulation in which we create environment/conditions to identify the cause of equipment failure. This can be the best and fastest method to identify the failure cause. A computer simulation (or "sim")
12788-412: The form of civics simulations, in which participants assume roles in a simulated society, or international relations simulations in which participants engage in negotiations, alliance formation, trade, diplomacy, and the use of force. Such simulations might be based on fictitious political systems, or be based on current or historical events. An example of the latter would be Barnard College 's Reacting to
12927-437: The head had moved one dot spacing in the time. The vertical dot position was controlled by a synchronized longitudinally ribbed platen behind the paper that rotated rapidly with a rib moving vertically seven dot spacings in the time it took to print one pixel column. 24-pin print heads were able to print at a higher quality and started to offer additional type styles and were marketed as Near Letter Quality by some vendors. Once
13066-429: The health professions. Simulators have been developed for training procedures ranging from the basics such as blood draw , to laparoscopic surgery and trauma care. They are also important to help on prototyping new devices for biomedical engineering problems. Currently, simulators are applied to research and develop tools for new therapies, treatments and early diagnosis in medicine. Many medical simulators involve
13205-527: The host system e.g., the Linux compatibility layer used on *BSD to run closed source Linux native software on FreeBSD and NetBSD . For example, while the Nintendo 64 graphic processor was fully programmable, most games used one of a few pre-made programs, which were mostly self-contained and communicated with the game via FIFO ; therefore, many emulators do not emulate the graphic processor at all, but simply interpret
13344-478: The importance of a decentralized and deinstitutionalized process for the preservation of digital culture. In many cases, the goal of emulation in new media art is to preserve a digital medium so that it can be saved indefinitely and reproduced without error, so that there is no reliance on hardware that ages and becomes obsolete. The paradox is that the emulation and the emulator have to be made to work on future computers. Emulation techniques are commonly used during
13483-468: The impression of the character form is printed onto the paper. Each system could have slight timing issues, which could cause minor misalignment of the resulting printed characters. For drum or typebar printers, this appeared as vertical misalignment, with characters being printed slightly above or below the rest of the line. In chain or bar printers, the misalignment was horizontal, with printed characters being crowded closer together or farther apart. This
13622-481: The key concepts. Normally, a user can create some sort of construction within the microworld that will behave in a way consistent with the concepts being modeled. Seymour Papert was one of the first to advocate the value of microworlds, and the Logo programming environment developed by Papert is one of the most well-known microworlds. Project management simulation is increasingly used to train students and professionals in
13761-405: The letter form then struck a ribbon which was pressed against the paper, printing one character at a time. The maximum speed of the Selectric printer (the faster of the two) was 15.5 characters per second. The common teleprinter could easily be interfaced with the computer and became very popular except for those computers manufactured by IBM . Some models used a "typebox" that was positioned, in
13900-615: The liquid ink on a rotating, oil coated drum. The paper then passes over the print drum, at which time the image is immediately transferred, or transfixed, to the page. Solid ink printers are most commonly used as color office printers and are excellent at printing on transparencies and other non-porous media. Solid ink is also called phase-change or hot-melt ink and was first used by Data Products and Howtek, Inc., in 1984. Solid ink printers can produce excellent results with text and images. Some solid ink printers have evolved to print 3D models, for example, Visual Impact Corporation of Windham, NH
14039-591: The low-cost laser printer in 1984, with the first HP LaserJet , and the addition of PostScript in next year's Apple LaserWriter set off a revolution in printing known as desktop publishing . Laser printers using PostScript mixed text and graphics, like dot-matrix printers, but at quality levels formerly available only from commercial typesetting systems. By 1990, most simple printing tasks like fliers and brochures were now created on personal computers and then laser printed; expensive offset printing systems were being dumped as scrap. The HP Deskjet of 1988 offered
14178-400: The method used to print onto the card. They are: Different ID Card Printers use different encoding techniques to facilitate disparate business environments and to support security initiatives. Known encoding techniques are: There are basically two categories of card printer software: desktop-based, and web-based (online). The biggest difference between the two is whether or not a customer has
14317-401: The military computer D-37C . Video game console emulators are programs that allow a personal computer or video game console to emulate another video game console. They are most often used to play older 1980s to 2000s-era video games on modern personal computers and more contemporary video game consoles. They are also used to translate games into other languages, to modify existing games, and in
14456-613: The model, the use of simplifying approximations and assumptions within the model, and fidelity and validity of the simulation outcomes. Procedures and protocols for model verification and validation are an ongoing field of academic study, refinement, research and development in simulations technology or practice, particularly in the work of computer simulation. Historically, simulations used in different fields developed largely independently, but 20th-century studies of systems theory and cybernetics combined with spreading use of computers across all those fields have led to some unification and
14595-463: The most common type of computer printer used by consumers. Solid ink printers, also known as phase-change ink or hot-melt ink printers, are a type of thermal transfer printer , graphics sheet printer or 3D printer . They use solid sticks, crayons, pearls or granular ink materials. Common inks are CMYK -colored ink, similar in consistency to candle wax, which are melted and fed into a piezo crystal operated print-head. A Thermal transfer printhead jets
14734-441: The norm in most military training processes and there is a significant amount of data to suggest this is a useful tool for armed professionals. A virtual simulation is a category of simulation that uses simulation equipment to create a simulated world for the user. Virtual simulations allow users to interact with a virtual world . Virtual worlds operate on platforms of integrated software and hardware components. In this manner,
14873-435: The operation of those systems. A good example of the usefulness of using computers to simulate can be found in the field of network traffic simulation . In such simulations, the model behaviour will change each simulation according to the set of initial parameters assumed for the environment. Traditionally, the formal modeling of systems has been via a mathematical model , which attempts to find analytical solutions enabling
15012-617: The opposite effect. According to all legal precedents, emulation is legal within the United States. However, unauthorized distribution of copyrighted code remains illegal, according to both country-specific copyright and international copyright law under the Berne Convention . Under United States law, obtaining a dumped copy of the original machine's BIOS is legal under the ruling Lewis Galoob Toys, Inc. v. Nintendo of America, Inc. , 964 F.2d 965 (9th Cir. 1992) as fair use as long as
15151-464: The other hand, the mechanical components of line printers operate with tight tolerances and require regular preventive maintenance (PM) to produce a top quality print. They are virtually never used with personal computers and have now been replaced by high-speed laser printers . The legacy of line printers lives on in many operating systems , which use the abbreviations "lp", "lpr", or "LPT" to refer to printers. Liquid ink electrostatic printers use
15290-639: The paper (but not impact, per se) and special purpose pens that are mechanically run over the paper to create text and images. Since the pens output continuous lines, they were able to produce technical drawings of higher resolution than was achievable with dot-matrix technology. Some plotters used roll-fed paper, and therefore had a minimal restriction on the size of the output in one dimension. These plotters were capable of producing quite sizable drawings. A number of other sorts of printers are important for historical reasons, or for special purpose uses. Printers can be connected to computers in many ways: directly by
15429-416: The player 30 seconds on a 300 MHz PC. Other programs, such as some DOS programs, may not even run on faster computers. Particularly when emulating computers which were "closed-box", in which changes to the core of the system were not typical, software may use techniques that depend on specific characteristics of the computer it ran on (e.g. its CPU's speed) and thus precise control of the speed of emulation
15568-411: The prediction of the behaviour of the system from a set of parameters and initial conditions. Computer simulation is often used as an adjunct to, or substitution for, modeling systems for which simple closed form analytic solutions are not possible. There are many different types of computer simulation, the common feature they all share is the attempt to generate a sample of representative scenarios for
15707-399: The pressure of the print head to be applied to a stack of two or more forms to print multi-part documents such as sales invoices and credit card receipts using continuous stationery with carbonless copy paper . It also has security advantages as ink impressed into a paper matrix by force is harder to erase invisibly. Dot-matrix printers were being superseded even as receipt printers after
15846-506: The price of inkjet printers dropped to the point where they were competitive with dot matrix printers, dot matrix printers began to fall out of favour for general use. Some dot matrix printers, such as the NEC P6300, can be upgraded to print in color. This is achieved through the use of a four-color ribbon mounted on a mechanism (provided in an upgrade kit that replaces the standard black ribbon mechanism after installation) that raises and lowers
15985-462: The printing business to Xerox in 2001. A dye-sublimation printer (or dye-sub printer) is a printer that employs a printing process that uses heat to transfer dye to a medium such as a plastic card , paper, or canvas . The process is usually to lay one color at a time using a ribbon that has color panels. Dye-sub printers are intended primarily for high-quality color applications, including color photography; and are less well-suited for text. While once
16124-463: The production of season tickets, for the production of school and college identity cards as well as for the production of national ID cards. The choice of print technology has a great effect on the cost of the printer and cost of operation, speed, quality and permanence of documents, and noise. Some printer technologies do not work with certain types of physical media, such as carbon paper or transparencies . A second aspect of printer technology that
16263-530: The province of high-end print shops, dye-sublimation printers are now increasingly used as dedicated consumer photo printers. Thermal printers work by selectively heating regions of special heat-sensitive paper. Monochrome thermal printers are used in cash registers, ATMs , gasoline dispensers and some older inexpensive fax machines. Colors can be achieved with special papers and different temperatures and heating rates for different colors; these colored sheets are not required in black-and-white output. One example
16402-572: The quality of service. It could be therefore hypothesized that by increasing the number of highly trained residents through the use of simulation training, that the simulation training does, in fact, increase patient safety. The first medical simulators were simple models of human patients. Since antiquity, these representations in clay and stone were used to demonstrate clinical features of disease states and their effects on humans. Models have been found in many cultures and continents. These models have been used in some cultures (e.g., Chinese culture) as
16541-409: The real world. In this broad sense, simulation can often be used interchangeably with model . Sometimes a clear distinction between the two terms is made, in which simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the simulation represents the evolution of the model over time. Another way to distinguish between
16680-526: The ribbons as needed. Color graphics are generally printed in four passes at standard resolution, thus slowing down printing considerably. As a result, color graphics can take up to four times longer to print than standard monochrome graphics, or up to 8-16 times as long at high resolution mode. Dot matrix printers are still commonly used in low-cost, low-quality applications such as cash registers , or in demanding, very high volume applications like invoice printing. Impact printing, unlike laser printing, allows
16819-419: The same advantages as a laser printer in terms of flexibility, but produced somewhat lower-quality output (depending on the paper) from much less-expensive mechanisms. Inkjet systems rapidly displaced dot-matrix and daisy-wheel printers from the market. By the 2000s, high-quality printers of this sort had fallen under the $ 100 price point and became commonplace. The rapid improvement of internet email through
16958-428: The same on a 7090. The compatibility feature on the 1410 only required setting a console toggle switch, not a support program. In 1963, when microcode was first used to speed up this simulation process, IBM engineers coined the term "emulator" to describe the concept. In the 2000s, it has become common to use the word "emulate" in the context of software. However, before 1980, "emulation" referred only to emulation with
17097-410: The simulated CPU. The logic of the simulated CPU can then more or less be directly translated into software algorithms, creating a software re-implementation that basically mirrors the original hardware implementation. The following example illustrates how CPU simulation can be accomplished by an interpreter. In this case, interrupts are checked-for before every instruction executed, though this behavior
17236-680: The software development to take place before the hardware is ready, thus helping to validate design decisions and give a little more control. The word "emulator" was coined in 1963 at IBM during development of the NPL ( IBM System/360 ) product line, using a "new combination of software , microcode , and hardware ". They discovered that simulation using additional instructions implemented in microcode and hardware, instead of software simulation using only standard instructions, to execute programs written for earlier IBM computers dramatically increased simulation speed. Earlier, IBM provided simulators for, e.g.,
17375-420: The study of operational semantics . Less theoretically, an interesting application of computer simulation is to simulate computers using computers. In computer architecture , a type of simulator, typically called an emulator , is often used to execute a program that has to run on some inconvenient type of computer (for example, a newly designed computer that has not yet been built or an obsolete computer that
17514-505: The system can accept input from the user (e.g., body tracking, voice/sound recognition, physical controllers) and produce output to the user (e.g., visual display, aural display, haptic display) . Virtual simulations use the aforementioned modes of interaction to produce a sense of immersion for the user. There is a wide variety of input hardware available to accept user input for virtual simulations. The following list briefly describes several of them: Research in future input systems holds
17653-428: The term simulation to refer to what happens when a universal machine executes a state transition table (in modern terminology, a computer runs a program) that describes the state transitions, inputs and outputs of a subject discrete-state machine. The computer simulates the subject machine. Accordingly, in theoretical computer science the term simulation is a relation between state transition systems , useful in
17792-549: The terms is to define simulation as experimentation with the help of a model. This definition includes time-independent simulations. Often, computers are used to execute the simulation . Simulation is used in many contexts, such as simulation of technology for performance tuning or optimizing, safety engineering , testing, training, education, and video games. Simulation is also used with scientific modelling of natural systems or human systems to gain insight into their functioning, as in economics. Simulation can be used to show
17931-415: The time to copy the program to be debugged at a low level and without introducing the side effects of a debugger . In many cases, the simulator is actually produced by the company providing the hardware, which theoretically increases its accuracy. Math co-processor emulators allow programs compiled with math instructions to run on machines that do not have the co-processor installed, but the extra work done by
18070-524: The user obtained a legally purchased copy of the machine. To mitigate this however, several emulators for platforms such as Game Boy Advance are capable of running without a BIOS file, using high-level emulation to simulate BIOS subroutines at a slight cost in emulation accuracy. Terminal emulators are software programs that provide modern computers and devices interactive access to applications running on mainframe computer operating systems or other host systems such as HP-UX or OpenVMS . Terminals such as
18209-435: The user's actions. Medical simulations of this sort will often use 3D CT or MRI scans of patient data to enhance realism. Some medical simulations are developed to be widely distributed (such as web-enabled simulations and procedural simulations that can be viewed via standard web browsers) and can be interacted with using standard computer interfaces, such as the keyboard and mouse . An important medical application of
18348-530: The virtual environment with relatively minimal effort. It is possible that these types of systems will become standard input modalities in future virtual simulation systems. There is a wide variety of output hardware available to deliver a stimulus to users in virtual simulations. The following list briefly describes several of them: Clinical healthcare simulators are increasingly being developed and deployed to teach therapeutic and diagnostic procedures as well as medical concepts and decision making to personnel in
18487-410: The wax tends to repel inks from pens , and are difficult to feed through automatic document feeders , but these traits have been significantly reduced in later models. This type of thermal transfer printer is only available from one manufacturer, Xerox , manufactured as part of their Xerox Phaser office printer line. Previously, solid ink printers were manufactured by Tektronix , but Tektronix sold
18626-411: Was a mechanically driven apparatus by Charles Babbage for his difference engine in the 19th century; however, his mechanical printer design was not built until 2000. The first patented printing mechanism for applying a marking medium to a recording medium or more particularly an electrostatic inking apparatus and a method for electrostatically depositing ink on controlled areas of a receiving medium,
18765-603: Was as clear and crisp as a typewriter. The fastest letter-quality printers printed at 30 characters per second. The term dot matrix printer is used for impact printers that use a matrix of small pins to transfer ink to the page. The advantage of dot matrix over other impact printers is that they can produce graphical images in addition to text; however the text is generally of poorer quality than impact printers that use letterforms ( type ). Dot-matrix printers can be broadly divided into two major classes: Dot matrix printers can either be character -based or line-based (that is,
18904-530: Was first developed by the United Nations Development Programme , and is now used in a very revised form by the World Bank for training staff to deal with fragile and conflict-affected countries. Military uses for simulation often involve aircraft or armoured fighting vehicles, but can also target small arms and other weapon systems training. Specifically, virtual firearms ranges have become
19043-723: Was in 1962 by C. R. Winston, Teletype Corporation, using continuous inkjet printing. The ink was a red stamp-pad ink manufactured by Phillips Process Company of Rochester, NY under the name Clear Print. This patent (US3060429) led to the Teletype Inktronic Printer product delivered to customers in late 1966. The first compact, lightweight digital printer was the EP-101 , invented by Japanese company Epson and released in 1968, according to Epson. The first commercial printers generally used mechanisms from electric typewriters and Teletype machines. The demand for higher speed led to
19182-427: Was much less noticeable to human vision than vertical misalignment, where characters seemed to bounce up and down in the line, so they were considered as higher quality print. Line printers are the fastest of all impact printers and are used for bulk printing in large computer centres. A line printer can print at 1100 lines per minute or faster, frequently printing pages more rapidly than many current laser printers. On
19321-424: Was started by retired Howtek employee, Richard Helinski whose 3D patents US4721635 and then US5136515 was licensed to Sanders Prototype, Inc., later named Solidscape, Inc. Acquisition and operating costs are similar to laser printers . Drawbacks of the technology include high energy consumption and long warm-up times from a cold state. Also, some users complain that the resulting prints are difficult to write on, as
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