The computer and it components

WHAT IS A COMPUTER, HARDWARE AND SOFWARE. DATA AND INFORMATION. THE IPOS CYCLE

So, let's look at what is a computer. On the slide here all the devices you see are computers. Some are more specialized than others, but they are all computers. So, what is computer? A computer is a general purpose device that can be programmed to carry out a set of arithmetic or logical operations automatically. So this sequence of operations it carries out, is called a computer program. And computer programs can be changed anyway we want and in this way the computer can solve many different problems. So all computers we know today are digital electronic computers based on microprocessors, but there was a time when the computers were mechanical devices. So if we look at what computers do computers basically store and process data to generate useful information. So, here we see data goes into the computer and information comes out. So data is normally used to refer to raw and unprocessed data and information is the result we get after processing this data. And this information for example can be used to draw conclusions or make decisions. So the information that we obtained in one processing stage can actually also be fed again as raw data to the next processing cycle to get new information. So when you think of a computer you think of an electronic device. But, actually this electronic device would be useless if it would not be for the software programs that make it work. So the computer definition includes the electronic device and its components, called hardware, and the computer programs that control it, called software. Software can be compared to an instruction booklet of a ready to assemble furniture for example as it has a step-bystep assembly instructions that guides the whole assembly process and indicates how you can make something. Computer hardware on the other hand is all the physical components of a computer system and these can be located inside the system or outside. In case they are outside of system we call them peripherals. So for example these components that are outside of the computer are keyboard, mouse and other input devices, it's for example the CPU, the memory, another chips needed to connect all the components. We have monitor, printer and any other output device we can think of. There is hard disks, DVD unit, flash memory drives, that can be used to store information permanently. There are communications devices that are used to connect to a local or remote network, like network cards or modems. And we have all the support electronics needed to make the system run,  as power supply, cable buses, cooling fans, etc. In the beginning of personal computers installing some new hardware in a computer could be a nightmare. Because some hardware configuration was necessary and we maybe need to change microswitches for example and we had to execute many configuration programs in order to make sure that hardware was installed in the correct way. Today most hardware devices and modern personal computers have operating systems and they include some form of plug and play capability that manage automatically most of the processes that you need to configure a new hardware to add to your personal computer. Manual hardware installation might sometimes be needed but this is only on occasions when you're using some specialized system that's running an operating system derived from unix for example like some linux distributions have. Computer hardware gets obsolete very fast and some material that is used in its manufacturing can be actually a big source of waste and pollution, so there are several initiatives nowadays to try to minimize or eliminate the impacts on the environment when we design, manufacture, use and dispose of computers and servers. So these initiatives are commonly known as green computing or green ICT, green IT or ICT sustainability. Whose objective is try to minimize and eliminate the impact of the environment when we dispose of all this hardware. So, as we indicated a computer is useless without a computer program that instructs it how to process data and manage devices. And computer software allows computers to perform specific tasks or applications. So in the computer basically there's two types of software, one is the system software and the other is the application software. So, the main systems software is the operating system and the operating system is loaded when we start up the computer and its objective is to manage the interaction of the user and all application software and the hardware devices on the computer. so, it will for example manage the access to files and orchestrate the execution of different programs. So the other type of software as compared to system software is application software. Application software is created to develop specific tasks and we can think for example of word-processing, creating spreadsheets, designing slide shows, calculating the stresses of a building or browsing the internet. So as we have describe with hardware, installing new software in the early days of computing could also be also be quite a tricky task but nowadays most software programs are just distributed with an automated tool that's called an installation wizard and it just guides user through an easy installation process. All computers basically work following and information processing cycle and this information processing cycle is known as IPOS which stands for Input Processing Output Storage as you can see here on the slide. So first what the computer needs is data to be entered into the system, this is the input. And for this the computer has specific hardware known as input devices that you use to input data into the system that is for example a keyboard or scanner. When this input is there the computer performs some operations on these data, which is the processing and this is done by the central processing unit or CPU. And after we finish all this processing the computer presents the results to the user and this is the output. And for this it also uses specific hardware which are called output devices, think for example of amonitor or a printer. So the result of all this processing can also be stored for future use and this is the storage part of the IPOS cycle and the storage just means saving, the data saving the programs or saving any other output for future use. For this the computer has permanent storage devices and you can think of the internal hard disk or removable disks, disks such as a pen drives. And the storage devices have input and output function. So in this video we have seen what is a computer and what are the most important components of it.

COMPUTER HISTORY
 In this video we will review the history of the first computers. Before the machines that we can consider real computers , there were some designs that can be considered the ancestors, Probably we should go back to the abacus as the first helper for the calculus but if we focus on automatic artifacts, the pascal calculator, the Pascaline, is one of the first antecedents. It was a machine that using gears could solve basic mathematical operations. Another relevant machine was the babbage's difference engine that was able to tabulate polynomial functions for example it could fill logarithmic or trigonometric tables that maybe you've used. But the first machine that we can consider a computer was the Z1, designed by Konrad Zusee in the period of the second world war. The only drawback was that it's was mechanical computer and it was never completed. On the other hand Alan Turing developed a set of devices focused on breaking the codes generated by the german army using the enigma machine. This machine was called the bombe and is considered the first electronic computer . the Mark I created by IBM was an electronic version of the Babagge analytic engine. In that period IBM thought that just 5 computers would be needed all over the world. The ENIAC was another relevant  machine,created by Pensylvania university and it is considered the first general-purpose computer. And finally in these historical review of the computers we have the univac.The univac was the first commercial computer that was sold to the United States census beureau. The technology used in computers has passed through four different generations: in the first one the technology was based on vacuum tubes that were huge devices like a bulb. In the second generation during the 50s, the technology was based on transistors and the third generation, that began the 60s, was marked by the appearance of integrated circuits, which incorporate all the components he in a small plate of silicon. Finally the fourth generation lasts until nowadays and it's based on the use of microchips, microprocessors. The current computers are like those ones, the only difference is that now they are just smaller and faster. and that's all thanks

TYPES OF COMPUTER
 So let's look at computer taxonomies, so we're going to look from supercomputers to smartphones. We start with supercomputers so we start by the ones that have the most calculus power, the fast and the most powerful ones, these are supercomputers. Supercomputers are designed for complex high demanding calculus tasks like weather forecasting or physical simulations or crypto analyzed, for example, and they're very expensive. His performance is measured in flops, it stands for floating point operations per second. After supercomputers comes mainframes. Mainframes are computers that are used by large organizations but are not as specific as supercomputers and they most are of the timer related with massive data applications, like bulk data processing, industrial customers statistics, enterprise resource planning, transaction processing and more recently big data analysis. For Insurance companies, banks, public administration and research centers to analyze big amounts of data to get information out of that. So modern mainframes can run multiple different instances of different operating systems at the same time and this is the technique of using a virtual machines and allows applications to run as if they were on physically separate computers. So while mainframes pioneered this capability this type of virtualization which virtual machines is now actually available on most families of computer systems although they do not always have the same degree of level of sophistication as mainframes. What a mainframe can also do is that they can add or hot swap system capacity without disrupting system function so they can do this with specific granularity that's not usually available in other servers solutions. So after mainframes come the servers and they are similar to mainframes because they act as a centralized resource provided with high capacity more than desktop computers. The main difference with servers and mainframes systems is that mainframes and oriented to running specific corporate applications like these big data analyis that we spoke about before. And servers are more focused on sharing resources so like for example are offering storage, internet access, computing power or database for users. So servers offer this services to the users. The range of prices and computing capacities is broader in servers than in mainframes, as you can find very small servers with capacities and prices thar are not much higher than that of a high end workstation and mainframes are always powerful and expensive computers. Nowadays most internet services are provided by servers that provides web pages, email, databases storage... So so both, mainframes and servers are multiuser machines, that this means that they attend simultaneously several users, typically much more than the number of processors they have. So, what they do in order to achieve that is to use a technique that's called time-sharing and we can see this a little bit here on the slide. Basically timeshare consists of assigning the resources of a machine to one user but during a very short period of time. So the computer changes this quickly among active users, and it does it so quickly that to the user it gives the sensation that the computers is only dedicated to the tasks they want the computer to do, but it's actually not true because it's doing the tasks of many users and this is what is called multitasking. So most of them have several processors working at the same time and access to shared memory devices and this is what is called multi-processing. So the processes can be assigned to solve different parts of the same tasks and this is called parallel processing. So in the particular case that a computer executes multiple computer processes in different processors it can also be called multiprogramming. So moving from multi-user computers like mainframes and servers to single user computers we have workstations. Workstations are at high end of personal computers and they have a very powerful CPU, lots of ram memory and most of times come with one or more high-capacity graphics cards. And workstations are typically dedicated to allow for 3D design, engineering simulation, medical imaging or stock market analysis for example. So then, after workstations, come personal personal computers that are more for the general public. It's a pc, that is most of the time a general purpose machine that is designed for end users They are relatively cheap and they are addressed to domestic and office users. So we do word processing, spreadsheets and presentations with them. So pc, a personal computers, suitable for mobile use is what we call a laptop or notebook. And actually what they do is integrate all the devices in a single body with low weight so we can carry around with it. And the weight can actually vary from three kilos and there are even laptops that are around one kilogram, and actually they are as powerful as desktop computers but their expansion capacities are more limited. So basically they might have less memory, smaller disks and maybe they don't have all the expansion ports that a desktop computer has. So over the last few years what we have seen as a replacement for laptops is tablets. So tablets are for users that have even more mobility requirements, because these tablets are very small, they have a touch screen and they have very intuitive interfaces that makes us able to use anywhere and actually. The fact that they are so intuitive and small has contributed to their fast introduction and many people are using tablets nowadays and they are even being introduced into reluctant sectors. So tablets focus mainly on media consumption, information retrieval, gaming and online communication. So finally we have smartphones. Smartphones are smaller than tablets They Are actually handheld computers and they were born as a fusion of cell phones and personal digital assistants PDA. And actually they allow us to be permanently connected and have a broad spectrum of applications that we can use, both from professional and productivity tools to education or leisure. So other mobile devices that we want to show are PDA, GPS or portable media players PMPs, because they are also small computers each with specific functions. So PDAs, as we've seen before it's a personal data assistant, it's a handheld device that was actually made to be a personal information manager. They were very popular at the late nineties and the early two thousands but they've disappeared mostly because actually ol their functionality has been incorporated into what we know nowadays as smartphones. But their main functions are to store personal information as telephone numbers, notes, photos, songs and any productivity tool, as a calculator for example, an appoinment book, a calendar. And provides communication tools like email and web access to connect to the Iternet. Then the other handheld computer are portable GPS devices, also handheld devices that are designed to give the user it's current position and can help him providing navigation tools. So also their function have been mostly integrated into what we nowadays know as smartphones and their popularity has dismished. But they still have a small niche of application for people that are trekking or car navigation. Finally we have PMPs or portable media players and these are also handheld devices that are designed to store and play audio, video and digital images in various formats. So they usually store the content in an internal flash memory or an external flash memory cards. And their function has also been integrated into modern smartphones so their presence in the market has also declined.

WEARABLE AND EMBEDDED COMPUTERS
 Wearable computing is a fast growing field and it includes actually all kinds of electronic computing devices that you can wear on the human body. So they're use in applications that require recording or sending data about a person's activity or health and can perform functions like.. well it can actually because of that contribute to persons health or helping workers do a job by providing computer power that it's integrated in the activities they do for their work. So for example you can think of wearable computers like headsets, watches you can put your wrist, jackets, eyeglasses or you could even have that implanted. So, as an example consider eyeglasses that you can wear at that have any integrated screen for a technician that wants to do maintenance and this glasses actually superimposed in real time manuals or images of the machine that this technician is fixing. Or think for example of an insulin pump that controls delivery of insulin to patients at intervals that the computer can detect it is necessary. Or think, for example, about a combat helmet for soldiers that can communicate with the command and gives him or her information about what can be found in the surroundings in the form of augmented reality that superimposes images captured by a camera in real life. So this is all examples of wearable computers. So finally there's also computers that are embedded into other big systems and this is called embedded computers. So this is when a small computer chips are inside another product or devices to control this devices or perform specific functions. So, nowadays actually they are in many electronic products and actually we use a lot of them on our daily lives. You can find them for example in your car, your car has dozens of embedded computers in there. And you can find them on household appliances like your microwave, your freezer, your dishwasher, they are in home heating and cooling devices. Like I said, cars and trains and airplanes and another vehicles and also in lifts and automatic scalators.

UPValenciaX: ISC101.2x Information Systems and Computer Applications, Part 2: Hardware