Chapter IIntroduction

ComSystEm, an acronym that stands for Computer Systems Emulator, is a computer application that is meant to verify, test and simulate a running Personal Computer, desktop or laptop. It uses an interactive, easy-to-learn drag-and-drop environment still of different computer parts. These parts are called hardware and software. These two need to be both present in order to build a working computer system.

The purpose of the system proposal is so that people seeking to “build” their acquire Personal Computers to the ground-up to satisfy their needs will not find concern in seeing what best PC specs they need or desire. People usually check for prices in stores or online, yet they do not know what result it will yield putting it all together. The ComSystEm is an efficient and enjoyable way of checking things out before they make the retract. The proposed system will be pretty much like a laboratory of sorts, prompting the users to do experiments and see what comes out of it. That way, the researchers’ system is usable as a tool for education in the field of basic computing, for the product demonstrates what can be done if for example, user attaches extra memory or a graphics card.

The application is intended for computer hobbyists and intended more to people who need a running information and simulation as to what works in a computer system. All these people must know how to spend a computer and have a small knowledge in hardware and software. For example, one must know at least what a monitor is, or what Windows XP is. Also, one must know what a computer is for. These basic information are available and are implemented in elementary courses. According to academon.com, (2004), Today, computers are in classrooms across the nation and being used in almost every subject as a teaching tool. With that said, basic knowledge in computing is not that hard to come by, especially if the readers of this paper are of youth.

Unruffled, for clarification, I will make a few terms clear for the readers to understand the project, and a little bit about computer systems themselves.

What is a Personal Computer? Webopedia defines it as thus (n.d.): A petite, relatively inexpensive computer designed for an individual user. In tag, personal computers range anywhere from a few hundred dollars to thousands of dollars. Now according to Wikipedia.org (n.d.): A desktop computer is a personal computer (PC) in a invent intended for regular spend at a single location, as opposed to a mobile laptop or portable computer. Desktop computers are the big, clunky computers we use at home to do electronic work like sending e-mail, chatting, writing a document, editing a photo or just playing games. It’s not hard to get a Desktop Computer up and running at home. The problem is, these things are really space-consuming, unlike the laptop computer, which the researchers would discuss next.

A laptop computer, usually called a notebook computer by manufacturers, is a battery- or AC-powered personal computer generally smaller than a briefcase that can easily be transported and conveniently used in temporary spaces such as on airplanes, in libraries, temporary offices, and at meetings. A laptop typically weighs less than 5 pounds and is 3 inches or less in thickness. Among the best-known makers of laptop computers are IBM, Apple, Compaq, Dell, and Toshiba. Laptop computers generally cost more than desktop computers with the same capabilities because they are more difficult to construct and manufacture(“A laptop computer”, n.d.).

Knowing this, the readers would now be aware that laptop computers are a lot lighter than desktop computers. Though not essential, the readers must know of this much as to distinguish the two, so that confusion may be avoided.

According to Wikipedia.org(n.d.), In computergraphical user interfaces, drag-and-drop or DnD is the action of (or support for the action of) clicking on a virtual object and dragging it to a different location or onto another virtual object. In general, it can be used to invoke many kinds of actions, or create various types of associations between two abstract objects.

As a feature, support for drag-and-drop is not found in all software, though it is sometimes a snappily and easy-to-learn technique for users to perform tasks. However, the lack of affordances in drag-and-drop implementations means that it is not always obvious that an item can be dragged.

Hardware is a comprehensive term for all of the physical parts of a computer, as distinguished from the data it contains or operates on, and the software that provides instructions for the hardware to acoomplish tasks. The boundary between hardware and software is slightly blurry – firmware is software that is “built-in” to the hardware, but such firmware is usually the province of computer programmers and computer engineers in any case and not an issue that computer users need to grief themselves with. (“Hardware” n.d.)

According to Whatis.com (n.d.), Software is a general term for the various kinds of programs used to operate computers and related devices. (The term hardware describes the physical aspects of computers and related devices.)

All according to Wikipedia.org(n.d.): A specification(specs) is an explicit set of requirements to be gratified by a material, product, or service. Computer data storage, often called storage or memory, refers to computer components, devices, and recording media that preserve digital data used for computing for some interval of time.

This project would not have been thought of by the researchers had they not seen what Cisco System’s simulator, Packet Tracer, does. According to Wikipedia.org (n.d.), Cisco Systems, Inc. is a multinational corporation with more than 66,000 employees and annual revenue of US$39 billion as of 2008. It designs and sells networking and communications technology and services. Also according to Wikipedia.org (n.d.), Packet Tracer is a powerful router simulator created by Cisco Systems and provided for free distribution to faculty, students, and alumni whom are or have participated in the Cisco Academy program. The purpose of Packet Tracer is to offer students and teachers a tool to learn the principles of networking as well as obtain Cisco Technology specific skills.

The prime reason as to why Packet Tracer became the inspiration to the project is because it uses a drag-and-click interface to send bits of data from a simulated computer to another. This fascinated the researchers and belief that they could do that to hardware and software. Also, the fact that the project will be an application that simulates using drag-and-click interface is the only similarity between Packet Tracer, and ComSystEm.

Objectives of the study

General Objective:

The general goal that the application Computer Systems Emulator wishes to invoke is to encourage people in canvassing for computer specifications. It also aims to be a tool for utilize in studying the computer system and how it works.

Specific Objective

1. To remove the constraints of canvassing through the consume of a system interface that shows users the effects of certain connections.

2. To show and describe each computer processes that is affected through certain computer specs.

3. To ascertain and confirm compatibilities of ports, switches and cards that is connected to the Central Processing Unit.

4. To check what components and peripherals will help improve computer performance.

5. To question and debug overall performance constraints for faster computer functionality.

6. To study which maintenance method will help improve computer performance.

7. To find out which sets of memory cards will improve or deteriorate gaming experience.

8. To simulate a multitasking environment and see when it will affect runtime efficiency.

Context of the study

A computer whiz knows the injure with regards to canvassing for prices. Computer hardware is not only difficult to come by, but also puts a large hole in the pocket for enthusiasts. The researchers also remember such times before, while checking the ever-trustworthy Gilmore IT Center. It was a time when one of the researchers bought a laptop computer and remembered how tiring it is to jog around and endure the crowds, also doing the same shopping scheme. He bought it for 28 000 pesos. The hard work paid off, though it really wasn’t easy.

Another problem that came with the canvassing is that people buying the hardware know not everything that there is to know about the hardware they buy, what they do, or which parts work with which. For example, one might not know which cards they need to buy so as to expand their memory. Also, they do not know the voltage requirements and the effects and differences it brings into performance. There also comes a time when they have to bring in other clunky stuff like motherboards so as to know what works and what doesn’t.

The project strives to attend or lessen some of these constraints.

The program that greatly helped the project’s conception was a networking simulator that the researcher Jimeno came across last year. The simulator goes by the name of Packet Tracer, made by Cisco Systems, Inc. for students enrolled in their networking training programs. The users can drag in a router, a switch, a repeater, a hub or a server. End-user hardware like personal computers and printers are also out of the question. Novel printers have network ports so users can print even if the printer is not directly connected to the PC, and can also be used by many computer systems. After dragging in the peripherals archaic in networking, one can connect each other through different types of known wires. After that, the user can turn on the power of the hardware like the router and PC. You can also send simulated packets (groups of data in form of bits) across the simulated network you have made. Errors would also be reported, from abominable wiring, to ambiguous network addressing.

Another inspiration was Will Wright, creator of many simulation games, from city managers, to life simulators. He is famous for his SimCity series and the Sims, which gives you great control over the virtual man.

ComSystEm strives to work this way, except that it works for computer hardware and focuses on the CPU more than anything. It helps users know what brings impact to computer performance, complete with simulated virus and malware attacks. Of course, it can also simulate what would happen if you install simulated games and determines when will your video games will insensible down or if it is compatible at all.

Significance of the study

In this fast-paced age of the 21^st century, people now rely on computers and other electronic gadgets like cellular phones all the time and in every station possible. Computers can be used and applied in all aspects of human living. Saying so means that computers have now become so indispensable to daily human life that even those who do not glance computing in colleges immerse themselves into devoting time for these electronic devices.

People are by nature ambitious, and by saying that, the researcher means that people still crave for better things, even if those they possess are already enough to sustain actual need. That is the main reason why the industry of computing continues to grow and evolve. Bigger and better products near along rather quickly and both hardware and software becomes obsolete.

People need better hardware and software. Those who do not canvass for prices of the ware they need will pick up it hard to prefer one, or may not get the best prices for it. Some of the Filipinos go to Gilmore IT Center near the LRT station to accomplish this task. Since the researcher has mentioned before that this is a fast-paced age, the people need something to lessen their time in deciding what parts do what, and how it affects the computer system. By using ComSystEm, canvassers in specific will spend less time deciding on what hardware they need. This program will not stop people from going to computer stores to check out prices, but this program will lessen their time in doing so, for the anxiety and confusion on what exactly is to bought will be omitted thanks to the application in sight.

Chapter II Review of Related Literature

Computer System Defined

According to Hutchinson and Sawyer (1992)”Computer is feeble to describe a device made up of a combination of electronic and electromechanical (part electronic and piece mechanical) components. By itself, a computer has no intelligence and is referred to as hardware. A computer doesn’t come to life until it is connected to other parts of a computer system (p.5),”

History of Computer hardware

The history of computers starts out about 2000 years ago, at the birth of the abacus, a wooden rack holding two horizontal wires with beads strung on them. When these beads are moved around, according to programming rules memorized by the user, all regular arithmetic problems can be done. Another critical invention around the same time was the Astrolabe, used for navigation.Blaise Pascal is usually credited for building the first digital computer in 1642. It added numbers entered with dials and was made to help his father, a tax collector. In 1671, Gottfried Wilhelm von Leibniz invented a computer that was built in 1694. It could add, and, after changing some things around, multiply. Leibniz invented a special stepped gear mechanism for introducing the addend digits, and this is still being used.The prototypes made by Pascal and Leibniz were not ancient in many places, and considered exclusive until a little more than a century later, when Thomas of Colmar (A.K.A. Charles Xavier Thomas) created the first successful mechanical calculator that could add, subtract, multiply, and divide. A lot of improved desktop calculators by many inventors followed, so that by about 1890, the range of improvements included:

• Accumulation of partial results
• Storage and automatic reentry of past results (A memory function)
• Printing of the results

Each of these required manual installation. These improvements were mainly made for commercial users, and not for the needs of science.

While Thomas of Colmar was developing the desktop calculator, a series of very intriguing developments in computers was started in Cambridge, England, by Charles Babbage (left, of which the computer store “Babbages, now GameStop, is named), a mathematics professor. In 1812, Babbage realized that many long calculations, especially those needed to form mathematical tables, were really a series of predictable actions that were constantly repeated. From this he suspected that it should be possible to do these automatically.

A step towards automated computing was the development of punched cards, which were first successfully stale with computers in 1890 by Herman Hollerith (left) and James Powers, who worked for the US. Census Bureau. They developed devices that could read the information that had been punched into the cards automatically, without human help. Because of this, reading errors were reduced dramatically, work flow increased, and, most importantly, stacks of punched cards could be used as easily accessible memory of almost unlimited size. Furthermore, different problems could be stored on different stacks of cards and accessed when needed. These advantages were seen by commercial companies and soon led to the development of improved punch-card using computers created by International Business Machines (IBM), Remington (yes, the same people that make shavers), Burroughs, and other corporations. These computers used electromechanical devices in which electrical power provided mechanical motion — like turning the wheels of an adding machine. Such systems included features to:

• feed in a specified number of cards automatically
• add, multiply, and sort
• feed out cards with punched results

As compared to today’s machines, these computers were slow, usually processing 50 – 220 cards per minute, each card holding about 80 decimal numbers (characters). At the time, however, punched cards were a huge step forward. They provided a means of I/O, and memory storage on a huge scale. For more than 50 years after their first use, punched card machines did most of the world’s first business computing, and a considerable amount of the computing work in science.

The start of World War II produced a mammoth need for computer capacity, especially for the military. New weapons were made for which trajectory tables and other essential data were needed. In 1942, John P. Eckert, John W. Mauchly (left), and their associates at the Moore school of Electrical Engineering of University of Pennsylvania decided to build a high – speed electronic computer to do the job. This machine became known as ENIAC (Electrical Numerical Integrator And Calculator) The size of ENIAC’s numerical “word” was 10 decimal digits, and it could multiply two of these numbers at a rate of 300 per second, by finding the value of each product from a multiplication table stored in its memory. ENIAC was therefore about 1,000 times faster then the previous generation of relay computers. ENIAC used 18,000 vacuum tubes, about 1,800 square feet of floor space, and consumed about 180,000 watts of electrical power. It had punched card I/O, 1 multiplier, 1 divider/square rooter, and 20 adders using decimal ring counters, which served as adders and also as quick-access (.0002 seconds) read-write register storage. The executable instructions making up a program were embodied in the separate “units” of ENIAC, which were plugged together to form a “route” for the flow of information.

Fascinated by the success of ENIAC, the mathematician John Von Neumann (left) undertook, in 1945, an abstract inspect of computation that showed that a computer should have a very simple, fixed physical structure, and yet be able to execute any kind of computation by means of a proper programmed control without the need for any change in the unit itself. Von Neumann contributed a new awareness of how practical, yet fast computers should be organized and built. These ideas, usually referred to as the stored – program technique, became well-known for future generations of high – speed digital computers and were universally adopted.

The first generation of modern programmed electronic computers to capture advantage of these improvements were built in 1947. This group included computers using Random – Access – Memory (RAM), which is a memory designed to give almost constant access to any particular piece of information. . These machines had punched – card or punched tape I/O devices and RAM’s of 1,000 – word capacity and access times of .5 Greek MU seconds (.5*10-6 seconds). Some of them could perform multiplications in 2 to 4 MU seconds.

Physically, they were much smaller than ENIAC. Some were about the size of a grand piano and used only 2,500 electron tubes, a lot less then required by the earlier ENIAC. The first – generation stored – program computers needed a lot of maintenance, reached probably about 70 to 80% reliability of operation (ROO) and were weak for 8 to 12 years. They were usually programmed in ML, although by the mid 1950’s progress had been made in several aspects of advanced programming. This group of computers included EDVAC (above) and UNIVAC (right) the first commercially available computers.

Early in the 50’s two important engineering discoveries changed the image of the electronic – computer field, from one of fast but unreliable hardware to an image of relatively high reliability and even more capability. These discoveries were the magnetic core memory and the Transistor – Circuit Element. These technical discoveries posthaste found their way into novel models of digital computers. RAM capacities increased from 8,000 to 64,000 words in commercially available machines by the 1960’s, with access times of 2 to 3 MS (Milliseconds).

In the 1960’s, efforts to design and build the fastest possible computer with the greatest capacity reached a turning point with the LARC machine, built for the Livermore Radiation Laboratories of the University of California by the Sperry – Rand Corporation, and the Stretch computer by IBM. The LARC had a base memory of 98,000 words and multiplied in 10 Greek MU seconds. Stretch was made with several degrees of memory having slower access for the ranks of greater capacity, the fastest access time being less then 1 Greek MU Second and the total capacity in the vicinity of 100,000,000 words. During this period, the major computer manufacturers began to offer a range of capabilities and prices, as well as accessories such as:

• Consoles
• Card Feeders
• Page Printers
• Cathode – ray – tube displays
• Graphing devices

The trend during the 1970’s was, to some extent, moving away from very powerful, single – purpose computers and toward a larger range of applications for cheaper computer systems. Most continuous-process manufacturing, such as petroleum refining and electrical-power distribution systems, now used computers of smaller capability for controlling and regulating their jobs.

In the 1980’s, very large scale integration(VLSI), in which hundreds of thousands of transistors were placed on a single chip, became more and more common. Many companies, some current to the computer field, introduced in the 1970s programmable minicomputers supplied with software packages. The “shrinking” trend continued with the introduction of personal computers (PC’s), which are programmable machines small enough and inexpensive enough to be purchased and customary by individuals. Many companies, such as Apple Computer and Radio Shack, introduced very successful PC’s in the 1970s, encouraged in part by a fad in computer (video) games. In the 1980s some friction occurred in the crowded PC field, with Apple and IBM keeping strong. In the manufacturing of semiconductor chips, the Intel and Motorola Corporations were very competitive into the 1980s, although Japanese firms were making strong economic advances, especially in the area of memory chips.

A small timeline from merchantos.com (n.d.) is shown below:

• 8,500 BC Bone carved with prime numbers found
• 1000 BC to 500 BC Abacus invented
• 1642 Blaise Pascal’s invented adding machine, France
• 1822 Charles Babbage drafted Babbage Disagreement Engine, England
• 1835 Babbage Analytical Engine proposed, England
• 1843 Ada Byron Lovelace computer program to calculate Bernoulli numbers, England
• 1943 Turing COLOSSUS the first programmable computer, England
• 1946 ENIAC first electronic computer, U.S.A.
• 1951 UNIVAC first computer broken-down by U.S. government, U.S.A.
• 1969 ARPANET Department of Defense lays groundwork for Internet, U.S.A.
• 1968 Gordon Moore and Robert Noyce found in Intel, U.S.A.
• 1977 Apple computers for consumers sold, U.S.A.
• 1981 IBM personal computers sold, U.S.A.
• 1991 World Wide Web consumer Internet access, CERN, Tim Berners-Lee Switzerland/France
• 2000 Y 2K Bug programming errors discovered
• Current Technologies include word processing, games, email, maps, and streaming

The term “Computer” refers to the machine used to calculate and organize data. The five basic components include: the hardware, software, data/information, procedures and people ware. When these five basic components work together, the sixth component comes out, the connectivity.

Data

Data refers to any known fact, and is a valuable component of a computer system. It could be in any form – facts about an employee, schedule of a baseball game, or the room assignment in a hospital. Pictures, sounds and videos are also considered as data. When introduced into a computer, these data can be converted into information, although that doesn’t necessarily mean all data must be introduced into a computer. Anybody, even without computer knowledge, can convert data to information, but that would be long and troublesome. According to Parker (1990) “anyone can go through an employee file and make a list of people earning a certain salary. But to do so would take a lot of time, especially for a company with thousands of employees (p.11).”

If done manually, data processing would take a lot of time and effort, not to mention that the reliability and accuracy of the data can be do to doubt (p26).”

Computers can with their electronically fast speeds, do such jobs almost instantly. This is called data processing.

Computer software

Computers, by themselves, can’t do anything unless somebody direct it to do something. Technically speaking, computer software is intangible in nature, not physically seen by the typical user. According to Shelly, Cashman and Vermaat(“Discovering Computers” 2007) “Software, also called programs, consists of a series of instructions that tells the computer what to do and how to do it(p.15)” software is a series of instructions that dictate and direct how a computer will do its functions.

Furthermore, computer software is categorized into two: System Software and Application Software. The two differ in a lot of aspects, particularly as to where they are implemented. In addition to this, system software are further subdivided into operating systems and into utility programs. According to Shelly et al.:

An operating system is a set of programs that coordinates all the activities among computer hardware devices. It provides a means for users to communicate with the computer and other software. Many of today’s computers use Windows XP which is one of Microsoft’s operating systems. When a user starts a computer, portions of the operating system load into memory from the computer’s hard disk. It remains in the memory while the computer is on. A utility program allows a user to perform maintenance. Type tasks usually related to managing a computer, its devices or its programs. Most operating systems include several utility programs that allow you to compose additional computer management functions.

An application software in the other hand are software programs designed to assist users with basic personal tasks. Examples of these tasks are sending emails or searching the web. One of the most important and widely used applications software is a web browser, which allow users to search, retrieve and send information over the internet. Some common web browsers are Internet explorer, Mozilla firefox, Netscape Navigator and Opera.

Other tasks that require application software includes the daily office task of writing a document, forming a presentation, managing database related information and tabulating data into a table form. Nowadays, these task can easily be done by a popular application owned, marketed and developed by Microsoft Corporation called Microsoft office. This application software include the MS Word, Access, Excel, and Powerpoint.

In addition to this, there are a lot more tasks that requires the encourage of application software. According to Shelly et al.(2007), These include “personal information management, trace taking, project management, accounting, document management, computer aided acquire, desktop publishing, paint/image editing, audio and video auditing, multimedia authoring, personal finance, legal, tax, preparation, home design and education.”

Overall, the software component of the computer systems brings the machine to life, and can be considered as the main ingredient that enables a computer to perform a specific task. According to Norton, (2006):

System software is any program that controls the computer’s hardware or that can be archaic to maintain the computer in some way so that it runs more efficiently. The two basic types of it are the operating system and the utility programs. An operating system tells the computer how to use its own components. Examples of operating system include Macintosh and Linux. An operating system is famous for any computer because it acts as an interpreter between the hardware, application programs and the user. When a program wants the hardware to do something, it communicates through the operating system. On the other hand, a utility program is a program that makes the computer system easier to use or perform highly specialized functions. It is used to manage disks, troubleshoot hardware problems and perform tools that the operating system may not be able to do. (pp. 32 – 33)

THE USER

The user component of a computer system refers to the individuals who use the computer in varied applications. It can include anyone from students, who use it for their homework and school projects, to business professionals, to maintain information about their business. According to Mortley and Parker (2007):

“The people involved in a computer system include both the people who create the computers work and those who use them. Computer users, or end users, are the people who use a computer to obtain information. Anyone who uses a computer is a computer user, including an accountant electronically preparing a client’s taxes, an office worker using a word processing program to acquire a letter, a shop-floor supervisor using a computer to check and see whether workers have met the day’s quotas, a college student analyzing science lab data, a child playing a computer game, and a person bidding at an auction over the internet. Programmers on the other hand are computer professionals whose primary job responsibility is to work on the programs that computers spend. Although some computer users may do exiguous amounts of programming to customize the software on their desktop computers, the distinction between a computer user and a programmer is based on the work that a person has been hired to do. In addition to programmers, organizations may use other computer professionals. For instance, systems analysts design computer systems to be used within their companies. Computer operations personnel, in incompatibility, are responsible for the day-to-day operations of spacious computer systems. Computer operations personnel are also often employed to help train users or assist them with their desktop computers and to troubleshoot user-related problems. (pp. 19-20)”

HARDWARE

The hardware component of the computer systems pertains to the tangible, physical plot of the system. It can be physically touched and be seen by the naked eye. Each individual component won’t stand on its own until it is incorporated inside the system and the user uses them. As stated by J. Stanley Warford(2005)”hardware is the physical part of the system. Once designed, hardware is difficult and expensive to change. Every computer has the ff. basic hardware components: input devices, output devices, memory devices, processing devices and storage devices (p.10).”

INPUT DEVICES

Input devices are any hardware component that allows you to enter data and instructions into a computer. Many of these input devices are external devices meaning they are not included in the system unit, particularly the CPU. Aside from that, most of these are plug-and-play, meaning it is not necessary to turn off the computer and for the system processor to find the appropriate driver when you want to build them to the computer system. Examples of input devices are the keyboard, which contain keys that are pressed to enter data into the computer. Desktop computer keyboards typically have 101 to 105 keys. Keyboards for smaller computers such as notebook computers contain fewer keys. All computer keyboards have a typing area that includes the 26 letters of the English alphabet, numbers 0 – 9, punctuation marks and other basic keys. Aside from these, there are also additional keys like the twelve function keys, two control keys, two alt keys, and arrow keys. Most modern keyboards also allow access to the computers CD/DVD drive and allow the connection of USB-enabled devices. It also allows the connection of wireless keyboard by means of infrared light waves or Bluetooth enabled receiver connected to the USB port.

Another popular input device is the mouse, which is a pointing device that allows users to control a pointer called the cursor. It is categorized into mechanical mouse or optical mouse. Mechanical mice have a rubber or metal ball in the underside to guide the movement of the cursor. An optical mouse, on the contrast, uses devices that emit and sense light to detect the mouse’s movement. Other pointing devices include the trackball, touchpad, pointing stick, joystick, control pad, gamepad, light pen, and digital pens.

OUTPUT DEVICES

Output devices are a different type of hardware devices that presents or interacts with the user through the information it presents. Common output devices include the display devices, hard copy outputting devices such as printers, speakers, headphones, fax machines and fax modems, data projectors and other devices.

According to Shelly et al. (2007) “A display device is an output device that visually conveys text, graphics and video information. Information on a present device, sometimes called soft copy, exists electronically and appears for a temporary period (p. 302).”

The most accepted display draw is the monitor, which can be classified into flat panel displays and CRT monitors. Flat panel displays as its name implies, are display monitors that are characterized as flat, with shallow thickness and usually produces brighter color and image detail than the CRT monitors. It is further classified into LCD screens and plasma monitors.

LCD monitor, also called flat panel monitor, is a desktop monitor that uses Liquid Crystals to produce image. It occupies less space and sometimes can be mounted to walls to maximize space savings, and usually used in intense graphic-filled environments, such as graphic designing and engineering. Plasma monitors, on the other hand, “Uses gas plasma technology, which sandwiches a layer of gas between two glass plates. When voltage is applied, the gas releases ultraviolet light. The UV light causes the pixels on the screen to glow and form an image. (“Discovering Computers 2007″ S.C.V. p. 306)”

CRT monitors are monitors that acquire a cathode-ray tube. The front of the tube is the shroud. Tiny dots of phosphorescent material coat the screen. Each dot colored red, green or blue. Those 3 colors, when combined, will perform a new color of a dot. Inside the CRT, an electron beam moves wait on and forth of the conceal to glow, this in turn produces the image that is being seen. In contrast to LCD monitors, CRT monitors are less expensive but generates more heat and require more power.

Another approved output device is the printer, which produces texts and images printed in different medium including paper or card. Printers are generally categorized as impact printer or non-impact printer. Non-impact printers produce text and images on a fragment of paper without actually touching the paper. One of the most celebrated non-impact printers are the inkjet printer, which produces text and images by spraying tiny drops of liquid ink onto a share of paper. Most inkjet printers can produce images in a variety of paper medium like bond papers, inkjet papers, photo paper, glossy paper or banner paper. Ink jet printers usually come with ink-filled print cartridges. These cartridges have many holes, or nozzles, where the ink comes out to produce an image. When the print cartridge would run out of ink, it can be replaced.

Photo printers produce photo-lab quality pictures. Most photo printers use inkjet technology, that can be attached to a computer to print images and texts. It usually comes with a built in card slot that can be used to print digital photos from a digital camera using a media card.

Another example of a non-impact printer is the laser printer. Laser printers usually print around 15 to 50 black and white pages per minute, and is usually referred to as page parameters, because it generates the entire page first before it can print it. For this reason, most laser printers contain 544MB to 20GB memory of hard disk. Laser printers use either PCL or PostScript to interpret the page, which in turn instructs the printer on how to layout the contents of a page to be printed. PCL, which stands for Printer Control Language, is developed by Hewlett-Packard and is a standard printer language used by most office transactions. On the other hand, Postscript is commonly used by graphic artist in designing complex documents with intense colors.

Other examples of non-impact printers are the thermal printers and the postage printers.

In difference, impact printers produce images by striking and inked ribbon that physically contacts the paper. Impact printers are usually noisy and produce poor quality outputs that is commonly used to print labels, envelopes and invoices. On the other hand, it is used because of its durability and toughness, particularly by factories and retail counters. Two of the most common impact printers are the dot-matrix printers and the line printers.

Other output devices include audio output devices, like speakers, headphones and earphones. Fax machines and fax modems are used to transfer data to and from a computer.

STORAGE DEVICES

Storage use to contain data and instruction for future use. According to Jun Jamrich Parsons and Dan Oja (2007) “A storage device is a mechanical apparatus that records and retrieves data from a storage medium. Storage devices include floppy disks, zip drives, hard disk drives, tape drives, CD and DVD drives. The term “Storage Technology” refers to a storage device and the media it uses (p. 78)”. Storage devices are a virtual component of a computer system. They usually comes in three types of technology which is either magnetic, optical or solid state.

Magnetic Storage Devices

Disk drives, hard disk drives, high capacity floppy disks drives and tape drives are examples of magnetic storage devices. The surface of these devices are coated with magnetically sensitive material, like iron oxide, that reacts to a magnetic field, thus they are classified as magnetic storage devices.

Hard disks are the most common mass storage device because of its cheap price and the huge amount of data it can accommodate. It is made up of aluminum platters coated with magnetic oxide stacked on top of each other, and is usually mounted on a central spindle. According to Norton (2006) “the hard disks found in most personal computers today spin at a speed of 3 600, 7 200 or 10 000 revolutions per minute (rpm). Very high performance disks found in workstations and servers can spin as fast as 15 000 rpm. When the platters rotate on the center spindle, a read and write head passes over the surfaces, and the data that is read is transferred to the memory.”

Other examples of storage devices are the removable high-capacity magnetic disks, which include the high-capacity floppy disks, more properly known as zip disks, and the hot-swappable hard disks. High-capacity floppy disks, also known as zip disks, can be added to computer system even if it has an existing floppy drive, and usually offers 100 MB to 750 MB.

Hot-swappable hard disks, on the other hand, usually arrive at a high price and are alternately called removable hard disks. It was termed “hot-swappable” because the user can remove one, called swap-out, and insert one, called swap-in, while the computer is still “hot” or still running, and doesn’t need to be turned off.

Tape drives are another example of storage devices that come with cheap tag and huge capacity. Its biggest downside however is that the tape drives are tiring, in accessing data because it reads the tape one byte at a time, to access the desired data, thus tape drives are commonly referred to as sequential access devices.

Optical Storage Devices

Optical storage devices include the CD ROM, DVD-ROM, and other varieties of it like the Compact Disc- Recordable (CD-R), CD Rewritable (CD-RW), PhotoCD, DVD-R and the DVD-ram. Optical Storage devices store data on a reflective surface that in turn is being read by a laser light. CD Roms are the most accepted medium of storing data in a disc, particularly audio and music. A standard CD can store up to 50 MB of data or about 70 minutes of audio. Compared to hard disk drives, CD-ROM drives are slower, due to the changing rotational speed of the disc.

Solid State Storage Devices

Solid state storage devices do not have moving parts like the magnetic disks or laser light like the optical disks, instead, they use integrated circuits to have data, making it a faster storage device than magnetic or optical devices. The most popular solid-state storage devices are the flash memory and the smart cards. Among the most popular flash memory are the Secure Digital Card (SD), the MultiMedia Card(MMC), the Universal Flash Storage and a lot more. The capacity of these cards usually range from 256 MB to 20GB, making it a favorite among hobbyists, who usually use it in digital cameras and other portable devices.

On the other hand, smart cards contain a small microprocessor in it that enables it to read, update or delete existing data. It needs a smart card reader to access the data stored in it.

Communications

The communications aspect of a computer system usually pertains to devices, access or means that permits two or more computers or other electronic devices to transmit data and other information. Almost all modern computer systems today are packaged with an array of communication devices that enables it to access and share information and data with other computer systems, and one major reason for this being after all, computers are meant to be used to share and retrieve data. A communication device is any type of hardware capable of sending data, instruction and information between a sending device and a receiving device. One popular communication hardware device is the modem. According to O’Leary (“Computing Essentials 2000-2001″, 2000), “The word modem is short for modulator-demodulator. Modulation is the process of converting from analog to digital. (p.142).” The modem enables most desktop computers to transfer and receive data across telephone lines, but it still enables the user to use the telephone line to communicate. Communication speed is typically measured in bits per second, and modems are usually classified as external, internal or wireless.

A network card, sometimes called a network interface card or NIC, is a device that can be installed on a computer expansion card, and provides access to a network. It comes in different forms, but are usually classified according to where it will be used. Network cards for desktop computers are usually inserted to the motherboard’s expansion slot and has a slot on which a cable connects. For mobile devices such as laptop and notebook computers, a special type of network card, usually called PC card or flash card, are inserted on the device’s PC slot to connect to a network.

A router is a communications device that enables the connection of multiple computers on other routers together and transmits data to its correct destination on the network. On the other hand, a hub pertains to a communications device that provides a central point for cables in a network and then forward it to one or more destinations.

Physical Transmission Media

Communication does not only pertain to hardware devices, but also to the means of exchanging data and information, and thus can be further subdivided into physical transmission media and wireless transmission media. Physical transmission media used in communications include twisted pair cable, coaxial cable and fiber-optic cable. Twisted-pair cable consists of 2 copper wires bundled together, covered by an insulator, and is usually twisted to minimize noise, which is an electrical disturbance that interrupts communications.

On the other hand, coaxial cables are a single copper wire that is usually covered by at least three layers; an insulating material; a braided metal; and a plastic outer coating. It is usually used in cable television wiring because it can cover wide areas.

The most popular among the cables that is being used today is the fiber optic cable. According to O’Leary(“Computing Essentials 2000 – 2001″, 2000) “In fiber optic cable, data is transmitted as pulses of light through tubes of glass. In terms of number of telephone connectors, fiber optic cables have over 26 000 times the transmission capacity of twisted pair cables (p.150).” Fiber optic cable is usually characterized as having a runt diameter, specifically half the diameter of the human hair. It usually covers a significantly shorter distance than coaxial cable, but transmits data more securely. It transmits data using beam of light rather than electronic pulses, making it faster than copper cables.

Wireless Transmission Media

Many computer systems rely on wireless transmissions media because it is more convenient than installing cables, and is usually used in locations where it is hard or nearly impossible to install cables. These include infrared, broadcast radio, cellular radio, microwaves and communications satellite.

Motherboard

A motherboard is a most important and valuable component of a computer system. Without a motherboard, one cannot connect the other peripherals to the CPU, no hard disk will be connected and no RAM will be connected as well. As the name pertains, it is like a mother to a child. No child will be conceived if there is no mother to bear it into the world. Much is same for the computer system.

According to Wikipedia.org (n.d.)”A motherboard is the central printed circuit board (PCB) in many modern computers, and holds many of the crucial components of the system, while providing connectors for other peripherals. The motherboard is sometimes alternatively known as the main board, system board, or, on Apple computers, the logic board. It is also sometimes casually shortened to mobo. “

According to Wilson and Johnson (n.d.)”If you’ve ever taken the case off of a computer, you’ve seen the one piece of equipment that ties everything together — the motherboard. A motherboard allows all the parts of your computer to receive power and communicate with one another.”

As stated by Sexy Bex (2005), A motherboard is also known as a main board, system board and logic board. A popular abbreviation is ‘mobo’. They can be found in a variety of electrical devices, ranging from a TV to a computer. Generally, they will be referred to as a motherboard or a main board when associated with a complex device such as a computer, which is what we shall look at. Assign simply, it is the central circuit board of your computer.

Also according to Sexy Bex (2005):

There are a lot of motherboards on the market to choose from. The colossal question is, how do you go about choosing which one is right for you? Different motherboards assist different components, and so it is vital you make a number of decisions concerning general system specifications before you can pick the true motherboard.

If you purchase your case before the rest of the components, the first factor to think about concerning motherboards is the size, or form factor. A beget factor is a standardised motherboard size. If you think about fitting a motherboard in a case, there are a number of mounting holes, slot locations and PSU connectors. The most popular motherboard form factor today is ATX, which evolved from it’s predecessor, the Baby AT, a smaller version of the AT (Advanced Technology) form factor. Generally speaking, nowadays a standard computer will have an ATX form factor motherboard: only special cases require different perform factors.

So now you know which size you need, what comes next? The following are all factors you need to consider.

The first important differential is which CPU the board supports. Two of the biggest makes of CPUs at the moment are Intel and AMD, yet you cannot buy motherboards that support the use of either: it will support one or the other, due to physical differences in the connectors. This is often referred to as a type of platform; for example, an ‘Intel platform motherboard’ means a motherboard with an Intel CPU. Furthermore, you must choose a specific type of processor; for example, an AMD Athlon 64 or Pentium 4. Therefore, you must choose which CPU you want before you can choose your motherboard. Both Intel and AMD processors are wonderful of running the same applications, but there are differences in price and performance depending on which one you choose.

Advantages and Disadvantages of Computers

Computers and computer systems can be found virtually anywhere in the show times. It dramatically has changed the society’s way of living in many different ways, particularly in government, education, sciences and businesses, and because of it, advantages and disadvantages can be seen. Some advantages are the speed, which means that an average computer can process a data to information in an enormously faster rush than a human being can, the reason being the computers use circuits in transferring and acquiring data, which in turn travels at incredibly fast speeds. Another advantage of computers is reliability. According to H.L. Capron and J.A. Johnson (“Computers, Electronic tools for an Information Age”, 2005) “Computers are extremely reliable. Of course, some might assume that even computers commit errors, but most of these errors made by computers are actually human errors (p. 6).” Most of these errors that attributed to computers were actually errors made by the individual who worn or programmed the instructions used by the computer. Aside from this, computers also have storage capabilities, which mean that computer systems can store big amounts of data, which can be located and retrieved efficiently. Computer systems have the capability to process and store large amount of information usually on a diminutive space, and it can do the data available whenever needed.

Hardware Compatibility

As time passes by, computer technology and systems evolved speedy, but unfortunately, it didn’t happen synchronously. One system component evolved more lickety-split than the other, thereby creating the problem that is hardware disagreement. Often the computer will not function if its system components are not compatible, or even if it does function, it will be in a tremendously slow rate. Incompatibility also happens when an individual upgrades or builds a computer system, but unfortunately failed to make sure that each component are within the so-called “time bracket”. Unfortunately, hardware to hardware compatibility is a little bit of trial and error and if something appears to be incompatible, it is really a simple matter of changing the component until the desired result is achieved. This is the reason why setting up the component of a computer system fragment by part is a hard task for everyone. According to “Build your contain PC”:

For the CPU to be compatible to the motherboard, it must have the same socket as the motherboard. Also, the CPU needs to be compatible with the motherboard’s chipset. The easiest way to check for compatibility is by checking the motherboard’s manufacturing website and look for the CPU section. Beware that some motherboards may need to have their BIOS updated before they can use positive processors. On the section of the RAM, it needs to have the same slot type as the motherboard. It could be SDRAM, DDR, and DDR2 and is often dependent on the socket type and sometimes on the CPU. LGA 775 uses both DDR and DDR2 Ram in some cases. RAM compatibility can be found by downloading the motherboard’s manual from the manufacturer’s website. For hard drives, currently virtually all motherboards wait on IDE.

All IDE connections are interchangeable, but if the motherboard only supports 100 MB/s, data is only transferred at 66 MB/s. Two IDE drives, any combination of hard disks or CD-rom, can be connected to one IDE connector on the motherboard for Serial-ATA interchangeable.

Unusual computer systems today are packaged with either DVD or CD drive built in to the CPU. The main reason being these drives are usually connected to either IDE or SATA and works in the same way as the hard disk. For the floppy drive, its connection looks similar to IDE except that it has lesser pins.

Low- level sound cards are usually embedded on the system board for basic sound needs, but to enhance performance, additional sound cards can be added to the system, and usually it is inserted into a Peripheral Control Interconnector (PCI) slot of the system board. These sound cards are used to improve sound quality and high volumes.

Power supplies connect to the motherboard through the ATX power connector, usually having 20 pins. On the side of the PC case, it must be vast enough to house all the compartments inside it. It is also important to make sure that there is enough power ventilation inside the case.

Refurbished Hardware

The unusual buyers, particularly Filipinos, love a good bargain. They frequent flea markets or so-called tiangge just to earn items at prices lower than what is usually found. The same goes with hardware. These peripherals aren’t cheap at all. In partial or full solution, people buy these so-called refurbished items. Though, what are refurbished hardware in exact?

According to Wikipedia.org (n.d.): Refurbishment is the process of maintenance or minor repair of an item, either aesthetically or mechanically.

“Refurbished,” in reference to computers or laptops, means that the equipment was returned to the manufacturer either because the customer simply didn’t want it or a minor problem was found. Before re-selling the equipment, manufacturers fix and certify the unit and sell it at a discount.

Refurbished products cannot be sold as fresh products in the US, which is why they are relabeled as refurbished or refreshed units even if they are good-as-new (if, for example, the unit was returned for some reason unrelated to the product itself, i.e., the customer changed his mind about the color). Refurbished items may have scratches, dents or other forms of cosmetic pain which do not affect the performance of the unit.

As quoted by the website wisegeek.com (n.d.):

Refurbishedcomputers are older used computer components that have undergone a thorough evaluation and restoration process that makes the computer fully functional. In general, a refurbished computer will sell at a price somewhat below a modern computer of similar make and model, and carry a limited warranty. A number of major computer manufacturers offer refurbishedcomputers for sale at discounted prices.

Refurbished products are not a new concept. In times past, typewriters were often offered as refurbished models at a vital discount. Because the typewriters were restored under carefully crafted quality standards, the devices were expected to have a usage life similar to that of a fresh and previously unused typewriter. The same is true today with refurbished computers.

In order to prepare computers for refurbishing, the process often begins with a total assessment of the system. This includes inspecting all the internal and external components of the computer to insure the unit is in a condition that merits the time and expense associated with refurbishing. As part of this inspection, any and all issues with hardware and software components are noted and scheduled for repair.

Once the computers are restored to full operating efficiency, they are tested thoroughly. This is to ensure that the refurbished computers are in compliance with the standards set in place by the manufacturer. As part of the refurbished technology process, some of the current features may be enhanced, such as the addition of RAM or the inclusion of a unique component that will take the place of an customary component. An example of this type of upgrade would be replacing a floppy disk drive with a CD burner and reader.

Refurbished computers provide several benefits to consumers. Because the reworked systems may sell for significantly less than a unusual computer, buyers who are on a tight budget may find they can afford a machine with more power and with an operating system they trust. This eliminates the need to resolve for a weaker computer that is configured to use an operating system or support software that is considered inferior or unfamiliar. Since many refurbished computers do come with some type of warranty as well as a limited service contract, the consumer still has protection similar to that offered with a modern system, but without the higher price tag.

For manufacturers, it is also possible to make an equitable amount of profit from the sale of refurbished computers in comparison to newly constructed computer systems. The process of refurbishing an essentially solid computer is much less than building a new one from scratch. This makes it possible to offer the refurbished units at a lower rate, but have much less in the way of component costs and labor involved in preparing the unit for sale.

While many companies claim to offer refurbishedcomputers, it is important for the consumer to settle what the vendor means by refurbished. In some cases, the system has not undergone a rigorous inspection and does not meet industry standards. When considering the purchase of one or more refurbishedcomputers, always gather information on exactly what was done as part of the refurbishing process and how the final product compares to a new unit. Companies who truly refurbish computers are usually happy to provide specifics about the process, while businesses that do no more than slight enhancements to a used system tend

to be very vague about what has been done to refurbish the system.

What is Simulation?

Modeling and simulation is a discipline for developing a level of understanding of the interaction of the parts of a system, and of the system as a whole. The level of understanding which may be developed via this discipline is seldom achievable via any other discipline.

Source: Aquino, Nympha B. et al., 2007

A simulation generally refers to a computerized version of the model which is run over time to study the implications of the defined interactions. Simulations are generally iterative in their development. One develops a model, simulates it, learns from the simulation, revises the model, and continues the iterations until an adequate level of understanding is developed.

Related Studies

Simulation Research

PC ASSEMBLY

The stare made by Lugo et al. (1997) deals with how to assemble a personal computer and upgrade it if the need arises. The researchers of the PC ASSEMBLY study made a windows applications that teaches them various know-how on how to repair, troubleshoot and upgrade computer systems, as well as installation for fresh-out-of-the-box computer systems to sets its optimization options for first-time use. These tutorials are inclusive of four modules. Three main modules and a special fourth module.

• Module 1 is composed of training modules for Motherboard, ram, Graohics Cards, CD Rom drive and sound cards.
• Module 2 is composed of training modules for Floppies, HDDs, SCSI Peripherals, Modem, Input devices and Internal tape drives.
• Module 3 is for printers and scanners.
• PC Error, shows audio/video errors in forms of modules.

The study of Lugo et al. mainly focuses on hardware. To quote their context:

Computer literature as well as computer science students, are masters of software and its application and yet, they lack the interest when it comes to hardware technology. This lack of hardware technology knowledge can be expensive on the user’s part. Concern should be bought to the top of the list in order to minimize the unnecessary expenses brought by such hardware quandary.

From choosing the basic hardware components to assembly to upgrading, a computer based training program (CBT) such as this could present detailed information to the curious non-technical person as well as for the technical person. It aims to provide technical knowledge to future computer science students, more so, to those who wish to overcome the difficulty in handling technical problems specifically when it comes to personal computer assembly, troubleshooting, repair and maintenance of IBM personal computers and compatible. The researchers include in this study the document theories, applications and techniques in management of the computers.

Developing a Computer-Aided Digital Circuit Design

Circuits are basic fundamentals in making any type of computer hardware. Decision making and data stride in terms of binary language, in which it is only detached of of high and improper input signals. The study in question also models real-world concepts such as mapping boolean functions.

Developing a computer-aided digital circuit design or simply known as DESCUIT which stands for designing circuit, is especially designed for electronic design beginners who are taking up subjects like Logic and Digital Originate.

Car Modeling System

The general objective of the study is to develop system that could aid the car owner in customizing a car without spending a tremendous amount of money and exerting much effort and time.

Their specific objectives are:

• Do time and money in customizing a car.

• Help storeowners in selling cars in the easiest and fastest ways.

• Prove that proposed system is economically,

• operationally and technically feasible.

The proposed system which is entitled “Car Customization” provides all functions vital to get the business productive. The automated system minimizes amount of work done by the personnel and lessens time spent in handling manual operations.

The first and most important feature of the proposed system is security function. Observing confidentiality measures, every personnel responsible in the control of the systems shall be given a username and password which will serve as his key into the system.

Every time the system will be opened, user will be prompted to log in window. In this window, user will type password and username that was given to him/her.

Second feature is user-friendliness of the system. In this feature, it takes into consideration the easiness for the user to operate the proposed system. The help button will be displayed in the veil to help as a guide of the users of the system in case deficiencies will occur. Accuracy of system is also considered.

Flood Simulation for Marikina City (Aquino Nympha et. al.)

The general objective of the study is to provide and to construct a Flood Simulation system for Marikina City that could help the city planners and authorities in designing, planning and formulating precautionary and preemptive measures on the flooding conditions of the metropolitan situation.

Flood Simulation System is a program designed to simulate flood conditions of Marikina City with the use of sensors that was embedded to the scaled model prototype, a miniature of Marikina City. The volume of water that would dispense to the miniature will be input by the user.

Commercial Simulators

Packet tracer

Packet Tracer is a powerful network simulation program that allows students to experiment with network behavior and ask “what if” questions. As an integral part of the Networking Academy comprehensive learning experience, Packet Tracer provides simulation, visualization, authoring, assessment, and collaboration capabilities and facilitates the teaching and learning of complex technology concepts.

Packet Tracer supplements physical equipment in the classroom by allowing students to create a network with an almost unlimited number of devices, encouraging practice, discovery, and troubleshooting. The simulation-based learning environment helps students develop 21st century skills such as decision making, creative and critical thinking, and problem solving.

Packet Tracer complements the Networking Academy curricula, allowing instructors to easily teach and present complex technical concepts and networking systems earn. With Packet Tracer, instructors can customize individual or multiuser activities, providing hands-on lessons for students that offer value and relevance in their classrooms. Students can compose, configure, and troubleshoot networks using virtual equipment and simulated connections, alone or in collaboration with other students. Most importantly, Packet Tracer helps students and instructors create their own virtual “network worlds” for exploration, experimentation, and explanation of networking concepts and technologies. The software is available free of charge to all Networking Academy instructors, students, and alumni.

Reference:http://www.cisco.com/web/learning/netacad/course_catalog/PacketTracer.html

Full system simulator

full-system simulator is a computer program that simulates computer systems at such a level of detail that complete software stacks from real systems can run on the simulator without any modification. A full system simulator effectively provides virtual hardware that is independent of the nature of the host computer. The full-system model typically has to include processor cores, peripheral devices, memories, interconnection buses, and network connections. Burly system simulation can speed the software development process by making it easier to detect, recreate and repair flaws.

http://en.wikipedia.org/wiki/Full_system_simulation

Simics 3.0, released in the Fall of 2005, included the following current technologies:

• Device Modeling Language (DML)

• Device Modeling Language Compiler (DMLC)

• Hindsight, claimed by Virtutech to be the world’s first general-purpose development tool for reversible execution

The addition of DML offers a faster way to create and configure non-standard devices such as ASICs and FPGAs. DML largely automates the routine task of creating code to manage the hundreds and often thousands of registers in a modern system. The DMLC DML compiler translates DML into high-performance device models that enable Simics to simulate complete electronic systems at a performance measured in speeds of up to billions of simulated instructions per second. DML enables developers to start programming earlier, saving time and capital early in the product life-cycle.

Virtutech has also integrated Simics 3.0 into the Eclipse framework. Simics provides paunchy system simulation, including reverse debugging and execution with Hindsight, to the users that are standardizing on Eclipse as their integrated development environment (IDE).

Simics is currently available for Microsoft Windows and Linux platforms. Most of its code runs in Python and Eclipse.Simics is a full-system simulator ragged to run unchanged production binaries of the target hardware at high-performance speeds. Simics was originally developed by the Swedish Institute of Computer Science (SICS), and then spun off to Virtutech for commercial development in 1998.

Simics can simulate systems such as Alpha, x86-64, IA-64, ARM, MIPS (32- and 64-bit), MSP430, PowerPC (32- and 64-bit), POWER, SPARC-V8 and V9, and x86 CPUs. Many operating systems have been run on various varieties of the simulated hardware, including MS-DOS, Windows, VxWorks, OSE, Solaris, FreeBSD, Linux, QNX, and RTEMS. The NetBSD AMD64 port was initially developed using Simics before the public release of the chip . The purpose of simulation in Simics is often to develop software for a particular type of embedded hardware, using Simics as a virtual platform.

http://en.wikipedia.org/wiki/Simics

gpsim

gpsim is a full system simulator for MicrochipPIC microcontrollers. It is distributed under the GNU General Public License.

From their website:

gpsim is a full-featured software simulator for Microchip PIC microcontrollers distributed under the GNU General Public License.

gpsim has been designed to be as accurate as possible. Accuracy includes the entire PIC – from the core to the I/O pins and including ALL of the internal peripherals. Thus it’s possible to create stimuli and tie them to the I/O pins and test the PIC the same PIC the same way you would in the real world.

http://en.wikipedia.org/wiki/Gpsim

Launch Virtual Platforms

Open Virtual Platforms (OVP), consisting of the freely available simulator OVPsim, a library of models of processors, peripherals and platforms, and APIs which enable users to construct their own models. The models in the library are open source, written in C, and include the MIPS 4K, 24K and 34K cores, the ARM7, ARM9, ARM11, ARM Cortex A8/A9 families, and also the ARC 600/700. Many of the processor models are validated by the IP providers. Also available as free open source are the MIPS Malta Full System simulation model and the ARM Integrator Full System simulation model.

Facsimile

The Facsimile project’s goal is to develop and maintain a high-quality, 3D, physics-enabled, discrete-eventsimulation/emulation library that can be used for industrial simulation and emulation projects in an engineering and/or manufacturing environment.

Facsimile simulations run on Microsoft Windows XP and Vista as well as on Linux, Mac OS, BSD and Unix.

Facsimile is open-source/free software and is distributed under version 3 of the GNU General Public License (GPLv3).

http://en.wikipedia.org/wiki/Facsimile_Simulation_Library

Physics Abstraction Layer

The Physics Abstraction Layer (PAL) is an open sourcecross-platformphysical simulationAPI abstraction system. It is similar to a physics enginewrapper, however it is far more flexible providing extended abilities. PAL is free software, released under the BSD license.

PAL is a high-level interface for low-level physics engines used in games, simulation systems, and other 3D applications. It supports a number of dynamic simulation methodologies, including rigid body, liquids, soft body, ragdoll and vehicle dynamics. PAL features a simple C++API, intuitive objects (e.g. Solids, Joints, Actuators, Sensors, Materials), and COLLADA, Scythe Physics Editor and XML-based file storage.

The Physics Abstraction Layer provides a number of benefits over directly using a physics engine:

• Flexibility – It allows developers to switch between different physics engines to see which engine provides their needs, as well as quickly testing a new engine.

• Portable – Developers are able to use the physics engine which provides the best performance for different platforms, and are able to write platform independent code.

• Security – If a middleware provider is acquired by another company or development is discontinued, developers can switch engines.

• Scalable – The abstraction layer allows developers to run their code on handheld console platforms up to supercomputers.

• Ease of consume – Implementation details of the physics engine are abstracted, providing a cleaner interface to the developer.

• Benchmarking – Researchers can directly compare the performance of various dynamic simulations systems.

PAL is designed with a pluggableabstract factory allowing code to be written and compiled once and allowing runtime selection of different physics engines, as well as feature upgrades.

http://en.wikipedia.org/wiki/Physics_Abstraction_Layer

ASCEND

ASCEND is a free, open source, mathematical modelling system developed at Carnegie Mellon University since the late 1980s. Its main uses have been in the field of chemical process modelling although its capabilities are general. It includes nonlinear algebraic solvers, differential/algebraic equation solvers, nonlinear optimisation and modelling of multi-region ‘conditional models’. Its matrix operations are supported by an efficient sparse matrix solver called mtx.

http://en.wikipedia.org/wiki/ASCEND

VisSim

VisSim is a visual block diagram language for simulation of dynamical systems and Model-based embedded system development. It is developed by Visual Solutions of Westford, Massachusetts. VisSim is widely archaic in control system build and digital signal processing for multidomain simulation and design. It includes blocks for arithmetic, Boolean, and transcendental functions, as well as digital filters, transfer functions, numerical integration and interactive plotting. The free VisSim Viewer lets anyone run VisSim diagrams. Coupled with VisSim/C-Code, an add-on product, VisSim performs code generation for real-time implementation of embedded systems. It can target small 16-bit fixed point systems like the Texas InstrumentsMSP430 (using only 340 bytes flash and 64 bytes of RAM for a microscopic closed loop PWM actuated system) as well as larger 32-bit floating point processors like Texas Instruments C6713. This technique of simulating system performance off-line, and then generating code automatically from the simulated diagram to run on the embedded system is known as “model based development”. Model based development is becoming widely adopted for production systems because it shortens development cycles. VisSim Version 7 has introduced 3D plotting and interactive 3D VRML animation.

http://en.wikipedia.org/wiki/VisSim

Tortuga

Tortuga is a software framework for discrete event simulation in Java. A Tortuga simulation can be written either as interacting processes or as scheduled events. A Tortuga simulation can have thousands of entities, and can be fraction of a larger Java system.

Tortuga simulations run on Microsoft Windows XP and Vista as well as on Linux, Mac OS, BSD and Unix. They can also be used in an applet environment, although this typically requires a signed applet. As part of its support for simulation, Tortuga employs tools from aspect-oriented programming, or AOP. You need not be familiar with AOP to employ Tortuga: your simulation classes are written in standard Java. However, the spend of AOP in Tortuga requires more elaborate compilation that mere javac. This has been wrapped up in an Ant task included in tortuga.jar. This task is the reason it is assumed Tortuga-based simulations are using Ant to build.

Tortuga was developed by Dr. Fred Kuhl and Dr. Richard Weatherly of The MITRE Corporation in 2004-2006 and they continue to maintain it.

network simulator

ns or the network simulator (also popularly called ns-2, in reference to its current generation) is a discrete eventnetwork simulator. It is popular in academia for its extensibility (due to its open source model) and plentiful online documentation. ns is popularly primitive in the simulation of routing and multicast protocols, among others, and is heavily used in ad-hoc networking research. ns supports an array of popular network protocols, offering simulation results for wired and wireless networks alike. It can be also used as limited-functionality network emulator.

http://en.wikipedia.org/wiki/Ns_(simulator)

OMNeT++

OMNeT++ is a component-based, modular and open-architecture discrete eventnetwork simulator. The most well-liked use of OMNeT++ is the simulation of computer networks, but it is also used for queuing network simulations, and other areas as well.

OMNeT++ is accepted in academia for its extensibility (due to its open source model) and plentiful online documentation. The main discussion forum is the mailing list.

OMNeT++ represents a framework near. Instead of containing explicit and hardwired abet for computer networks or other areas, it provides an infrastructure for writing such simulations. Specific application areas are catered by various simulation models and frameworks, most of them inaugurate source. These models are developed completely independently of OMNeT++, and follow their own release cycles.

http://en.wikipedia.org/wiki/OMNeT%2B%2B

GoldSim

GoldSim is dynamic, probabilisticsimulation software developed by GoldSim Technology Group. This general-purpose simulator is a hybrid of several simulation approaches, combining an extension of system dynamics with some aspects of discrete event simulation, and embedding the dynamic simulation engine within a Monte Carlo simulation framework.

While it is a general-purpose simulator, GoldSim has been most extensively used for high-profile environmental and engineering risk analysis, with applications in the areas of water resource management, mining, radioactive waste management, and most recently, geological carbon sequestration and aerospace mission risk analysis.

http://en.wikipedia.org/wiki/GoldSim

Groundwater models

Groundwater models are computer models of groundwater flow systems, and are used by hydrogeologists. Groundwater models are used to simulate and predict aquifer conditions.

Groundwater models can be one dimensional, two dimensional, semi three dimensional and truly three dimensional.

One dimensional models can be frail for the vertical flow in a system of parallel horizontal layers.

2-dimensional models apply to a vertical plane while it is assumed that the groundwater conditions repeat themselves in other parallel vertical planes. Spacing equations of subsurface drains are an example of a two-dimensional groundwater model (see for example the page Groundwater energy balance where drainage equations based on the energy balance of groundwater hobble are discussed).

http://en.wikipedia.org/wiki/Groundwater_model

SimCity

SimCity is a city-buildingsimulationgame, first released in 1989 and designed by Will Wright. SimCity was Maxis‘ first product, which has since been ported into various personal computers and game consoles, and spawned several sequels including SimCity 2000 in 1993, SimCity 3000 in 1999, SimCity 4 in 2003, SimCity DS, and SimCity Societies in 2007. The original SimCity was later renamed SimCity Classic. Until the release of The Sims in 2000, the SimCity series was the best-selling line of computer games made by Maxis.

The objective of SimCity, as the name of the game suggests, is to build and design a city, without specific goals to achieve (except in the scenarios, see below). The player can mark land as being zoned as commercial, industrial, or residential, add buildings, change the tax rate, beget a power grid, build transportation systems and many other actions, in order to enhance the city.

Also, the player may face disasters including: flooding, tornadoes, fires (often from air disasters or even shipwrecks), earthquakes and attacks by monsters. In addition, monsters and tornadoes can trigger train crashes by running into passing trains. Later disasters in the game’s sequels included lightning strikes, volcanoes, meteors and attack by extraterrestrial craft.

In the SNES version and later, one can also build rewards when they are given to them, such as a mayor’s mansion, casino, etc.

http://en.wikipedia.org/wiki/SimCity

Definition of terms

Bandwidth – is a measure of available or consumed data communication resources expressed in bit/s or multiples of it (kbit/s, Mbit/s etc).

Byte-is a unit of information storage representing the smallest addressable element for a given computer architecture. It often designates a sequence of bits (binary digits) whose length is certain by the architecture. However, the use of a byte to mean eight bits has become ubiquitous.

Circuit – is a network that has a closed loop, giving a return path for the current. A network is a connection of two or more components, and may not necessarily be a circuit.

Hardware (computer) – A personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator’s desired functions.

KB – Kilobyte (kB), a unit of information used, for example, to quantify computer memory or storage capacity. a unit of digital information storage equal to either 1,000 bytes (10³) or 1,024 bytes (2¹⁰), depending on context.

MB – The megabyte is an SI-multiple (glance prefix mega-) of the unit byte for digital information storage or transmission and is equal to 10⁶ (1000000) bytes. However, due to historical usage in computer-related fields it is aloof often used to characterize 2²⁰ (1024×1024 or 1048576) bytes.

PC – short for Personal Computer. A computer whose original sales designate, size, and capabilities make it useful for individuals.

Peripheral – is a device attached to a host computer but not part of it whose primary functionality is dependent upon the host, and can therefore be considered as expanding the host’s capabilities, while not forming part of the system’s core architecture.

Software – is a general term used to describe the role that computer programs, procedures and documentation play in a computer system.

Simulation – is the imitation of some real thing, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system.

Source: http://en.wikipedia.org

Bibliography

S. Hutchinson, S. Sawyer “Computers, the User Perspective”; Richard Irwin Inc., Boston Ma. 02116; 1992; p. 5

G. Shelley, T. Cashman, M. Vermaat “Discovering Computers”; 2007

Peter Norton, “Introduction to Computers”; McGraw-Hill Technology Education, 1221 Avenue of the Americas, New York NY 10020; 2006

Deborah Morley, Charles S. Parker “Understanding Computers: Today and Tomorrow”; 11^th Edition, Thomson Course Technology 25 Thomson Place, Boston Massachusetts, 02210;

J. Stanley Warford “Computer Systems” Third Edition; 2005; Jones and Bartlett Publishers Inc. 40 Tail Pine drive, Sudburry, MA 01776.

June Jamrich Karsons, Dan Oja ; “Computer Concepts” 9th Edition ; Thomson Course Technology, 25 Thomson Place, Boston Ma. 02210

Timothy J. O’Leary, Linda L. O’Leary “Computing Essentials 2000 – 2001″; 2001; The McGraw-Hill Companies Inc. 1221;Avenue of the Americas, Recent York NY 10020; 2006

H.L. Capron, J. A. Johnson “Computers, Electronic Tools for an Information Age”; 2005; Pearson Education Inc. Upper Saddle River, New Jersey 07450

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