Week 2-Session 3-Storage Devices, I/O Devices & Other Peripheral Devices

We use our eyes, ears and the sense of touch to input data into our system. And the computers have their own devices of input and output. So here they are…..

Input devices

• The Keyboard: Keyboards come in all sizes and designs. But the symbols in them are all the same and are in the same format. There are keyboards called ergonomic keyboards which are designed to reduce the wrist and hand injuries.
• Pointing Devices: This is an input device that allows a user to control a pointer on the screen. A pointer is a small symbol on the screen whose location and shape changes as a user moves a pointing device.The most popular pointing device in the world is the mouse. But there are also other pointing devices like the trackball, pointing stick, touchpad, touch screen and pen input.
• Game controllers: Video games and computer games use game controllers as input devices to control the movements in the game playing on screen.These are the names of some types of game controllers; Gamepads, Joysticks and wheels, Light guns, Dance pads, Motion-sensing controllers etc.
• Digital Cameras: You can take pictures and keep it stored digitally through a digital camera. he pictures and videos stored in a digital camera can be transferred to the computer using a USB data cable. The types of digital cameras include; studio cameras, field cameras and point-and-shoot cameras.
• Voice Input: You can input voice to a computer using a microphone and the computer is capable of recognizing the spoken words, It can also be recorded using a recorder.
• Video Input: A web cam is used to input video into the computer. These videos can also be recorded. A web cam is also capable of capturing images.
• Scanners and Reading devices: Data is captured directly from invoices, paychecks and photos etc. through a scanner. Popular types of scanners are; Flatbed, Pen or hand-held, Sheet-fed and Drum. Many scanners include a software called OCR (optical character recognition).

Output Devices

• Display devices: A display device visually conveys text, graphics and video information. The most obvious example of display device is the monitor.
• Printers: A printer gives out hard copies of text and graphics on paper,There are two basic types of printers. It could be either Impact or non-impact.
• Audio output devices: It’s a computer component that produces music, speech and other sounds. Speakers and headsets are very common examples.
• Data Projector: This device projects a normal monitor’s display into a larger screen display.

So these are the basic input and output devices of the computer. And all these devices are equally important for a computer to function properly.

 

Storage Devices

 

If data are not stored electronically, it takes up much space. Just think If you don’t have a USB drive, you will have trouble with carrying large chunks of papers in bulky files wherever you go! Storage devices gives us much free space while providing a cleaner and a less messed up way of saving data.

Here are the storage devices that make our lives easier and free of space….

• Hard disks: A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions and information. It’s always safe to keep a backup of our hard disks just in case a head crash occurs. An external hard disk is a separate free-standing hard disk that connects to your computer with a cable or wirelessly. A removable hard disk is a hard disk that you insert and remove from a drive. There are also miniature hard disks available.
• Flash memory storage: Flash memory chips are a type of solid state media and contains no moving parts. SSDs (solid state drives) have several advantages when compared to magnetic hard disks like, faster access time and transfer rates, last longer and generates less heat and consumes less power.
• Cloud Storage: Cloud storage is an internet service that allows users to store data. Any amount of data can be stored in the air and there’s also privacy to your data. And there’s no chance of data getting lost as you might experience when the disks go dead.
• Optical disks: An optical disk consists of a flat, round, portable disk made of metal, plastic and lacquer that is written and read by a laser. Optical discs can store software, data, digital photos, movies and music. There are three types of optical disks. The first is CD-ROM (can be read from but not written to). The second is CD-R ( this is a disc where you can write, but not erase). The third is CD-RW (an erasable multisession disk)

Storage devices play an important part in our lives even if we don’t realize it. The population of the world keeps expanding and we don’t have extra space to store huge files and files of information. That’s when the storage devices come into our rescue.

Week 2-Session 2-Motherboard,CPU & Main Memory

The System Unit

The system unit is the carrier case of the electronic components. This is the black box of the computer which include processor, memory, expansion cards and most storage devices. It’s just like our head which carries our brain which is protected by a skull.

What’s inside the system unit?

• Processor
• Memory module
• Expansion cards

-Sound Card

-Modem Card

-Video Card

-Network interface card

• Ports and connectors

Motherboard

Motherboard is let’s say something like the kidneys of the computer.It is the main circuit board of the system unit. It contains chips, integrated circuits and transistors. A motherboard can also be known as the system board of the computer.

Processor

The processor is the most important part of the computer. Just like our brain. It processes the data and controls the computer. It’s normal to have one processor in each PC. But powerful computers used as servers have more than one processor. The data transfer between the processor and memory is done through the system bus. Each part of the memory has its own memory address and the processor determines where processed data is stored by sending an address signal along an address bus and data along a data bus.

Central Processing Unit

CPU is the processor + memory. Sometimes, the processor is called the CPU. It takes all major decisions, makes all sorts of calculations and directs all parts of the computer functions by activating and controlling the operations. Megahertz (MHz) is a measure of a CPU’s processing speed or clock cycle in millions per second.

The main functions of the CPU includes;

• Converting data into information
• Acting as the control center for the computer
• Executing stored program instructions

The central processing unit is divided into two as;

• Control unit (CU): This part of the CPU communicates with other parts of the hardware. It directs the computer system to execute stored program instructions.
• Arithmetic & Logic unit (ALU): Performs arithmetic operations and performs logical and relational/comparison operations.

Main memory

There are two types of memory. RAM (random access memory) and ROM (read only memory)

• RAM: It holds the program instructions and the data that is being used by the processor. RAM is volatile which means it looses its contents when power is turned off.
• ROM: This holds the program instructions and settings required to set up the computer. ROM is non-volatile which means that it does not loose its contents when power is turned off.

So these are the basic ingredients for a computer to perform its basic tasks. No other hardware component can take the place of any of these three components because the functions performed by these three components are unimaginable. And if you purchase a computer that weighs around 1000 kilos, you pay half of the price for the little CPU which weighs only around 50 grams.

Week 2-session 1-Computer History,.Architecture & Catergories of Computers

Computer History

 

 

 

The computer was not fully equipped with all the fantastic capabilities since it started. Just like us, it grew step by step to the luxurious models we see now. And just like us human beings, computers have their own history and their own generations. Here’s a glimpse at the history of computers.

 

 

• Pre-computers and early computers (before 1940): Our ancient civilizations had the ability to count and compute. And the basic things they used to do these were the Abacus (earliest recorded calculating device), slide ruler, mechanical calculator, punch card, tabulating machine and sorter. 

• First Generation (1940-1950) : Vacuum Tube; This was designed by Mauchly & Echert, built by US army to calculate trajectories for ballistic shells during world war ll

• Second Generation (1950-1964): Transistors; Vacuum tubes were replaced by transistors by William Shockley, John Bardeen and Walter Brattain. Transistors used the first operating systems which handled one program at a time. It also included on-off switches which were controlled electronically.

• Third Generation (1964-1974) : Integrated Circuits (IC); These computers had microprocessor chips that combined thousands of transistors and an entire circuit on one computer chip. Also, there were more than one computer models with different performance characteristics.

• Fourth Generation (1974-Present) : VLSI / ULSI ; VLSI stands for Very Large-scale integration and ULSI stands for Ultra large-scale integration. Computers in this generation have millions of transistors combined. They are also equipped with single-chip processors. It was in this generation that Personal Computers (PCs) were invented.

• Fifth Generation (now and the future): Computers in this generation are based on artificial intelligence. Computers are made to think, reason and learn! The primary means of input in these computers are voice and touch. The computers in this generation could be the ones that utilize nanotechnology or they can come as entire general-purpose computers.

If you compare the first generation computers to the computers these days, there will be a huge difference. This is an example as to how human beings learn by doing. Someone started it and the rest of them remodeled it and came up with much better and compact designs with more capabilities. If they had just stopped there, without thinking of remodeling and improving it, we won’t have the easy PCs today to complete huge chunks of office work!

 

Computer Architecture

All our human bodies are created according to an architecture. So are computers. These architectures have never changed since 1946 which means that the components of this architecture are essentials for each and every computer.

 

 

• Processor: the centre for manipulation and control
• Memory: storage for instruction and data for currently executing programs
• I/O System: Controller which communicates with “external” devices: secondary memory, display devices, networks.
• Data-path & control: Collection of parallel wires, transmits data, instructions , or control signal.

Since 1946, all computers have had these components. Just like we have all had brains, hearts and nervous systems.

Catergories of Computers

These computers are categorized based on size, capability and price.

• Embedded computer

Embedded computers are miniature computers that are embedded into a specific product to perform a specific function.

•  Mobile Computers

The best examples are our mobile phones which easily fit on our lap/hand and which contains built-in computing or internet capabilities.

•  Personal computers

These can be portable computers like laptops and notebooks or desktop computers. Personal computers are fully functioning and are designed for a single user at a time.

• Midrange Servers

These look like small cabinets, hosting data and programs available to a small group of users.

• Mainframe computers

These are powerful computers consuming large space which are used to host a large amount of data and programs available to a wide range of users.

• Super computers

These are extremely powerful computers used for complex computation and processing.



week 1 part 3 Number Systems

We humans, use the alphabet to create words to create sentences that make sense when we speak. And if by any chance, someone uses numbers to speak instead of words, that will sound insane. In case of computers, it’s the other way around. Words don’t make sense to computers. They understand a strange language created through these number systems listed below.

• Decimal number systems: Ten numerals are included in this number system which are as follows. 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. These numbers have a base (also known as radix) of 10 Written as X₁₀.

• Binary number systems: Only two numerals are included in this system. They are, 0 & 1.These two numbers are also known as BITS. Binary numbers have a base/radix of 2, written as X₂. This is the number system used by computers. All the information in the digital computer is represented as bit patterns.

• Octal number systems: Eight numerals are used to form a string of numbers. They are, 0, 1, 2, 3, 4, 5, 6 and 7. Octal numbers have a base or radix of eight, written as, X

• Hexadecimal Number systems: Sixteen symbols (numerals + letters) are used to form a string of numbers in this number system. They are, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F. Also known as Hex. Binary numbers have a base of sixteen, written as X. This number system is used to represent digital data.

These number systems are quite confusing. Specially when it comes to conversion of number systems. The one who invented these for sure must be a genius.

week 1 part 2 Computer Components

If you take a human being, there are two parts of him/her. The inside and the outside. For the human being to work perfect, both the inside and the outside should be in good condition. Just like that, even the computer is divided into two components. The inside and the outside. In other words, or in more used terms, it’s the computer hardware and software. So these two components of the computer are quite similar to the inside and outside of human beings. This fact makes me wonder that perhaps Charles Babbage, the one who invented the computer had and idea of creating an electronic version of the human being. And if this was his intention, I should say that I’m impressed at he was quite close. Not very.

• Computer Hardware : The computer hardware includes the electrical, electronic or mechanical parts of the computer. Anything in the computer that can be touched comes under computer hardware. The hardware parts of the human body includes hands, legs, eyes, ears, nose and each and every part of body. The hardware components of the computer include keyboard, mouse, monitor, CPU etc. The computer hardware can be classified into 5 parts.

- Input devices: Keyboard, webcam, microphone, scanner etc.

 

- Output devices: monitor, printer, scanner etc.

 

- System Unit: This includes the ALU and CU .

 

- Storage devices: Hard disks, optical disks and USB drives.

 

 - Communication devices: Routers, hub, switches and brides.

 

• Computer software : Computer software is the inside part of the computer. It’s also known as a program – a series of related instructions, organized for a common purpose. This is somewhat similar to the human mind. Every action we do through our physical parts are a result of what’s going on in our minds. So we do the perfect actions if our minds are free of bad thoughts and are developed to think positive. The software of the computer /the computer mind is divided into two categories as;

 - System software: designed to operate the computer hardware and to provide a platform for running application software.         Ex: The windows operating syetem.

- Application software: designed to help the user to perform specific tasks. Example; Windows media player & Microsoft office etc.



If the computer is just like a human being, and if it has exactly what a human being has (like the hardware and software), what is it that differentiate the two? I guess it’s the feelings. Computers don’t have feelings like us. And if any computer scientist invents a software with which the computer can feel exactly like us, then there will be no difference among computers and human beings at all!

 

Week 1-session 2 Computer Operations

In this week, we learnt the very basics of the computer. We learnt about the operations of the computer, the computer hardware and software,

Computer Operations

The computer is simply a programmable devise which carries out certain tasks it has been instructed to do. I believe that it’s somewhat like the human brain. Much faster. I’m not sure as to which has the best performance. Still, many people prefer to do most of their tasks using a computer than using their brain. Of course, the computer can do certain things the brain cannot. For example, which human would be able to do the calculations a computer does in excel? On the other hand, there are many things that a computer cannot do when compared to the human brain.


The four basic Computer operations are

1. Input : The computer can take in any data. It uses the keyboard, microphone, webcam and other devises like disks and usb drives to take in data. Just like the brain uses our eyes, ears and mouth to take in input.
2. Processing : The computer is capable of processing the data from input to useful information. Data is what comes in as input (unprocessed) and information is what goes out as output after the data is being processed. Every time I hear the word processor, I see the picture of a food processor where you add different kinds of food into the processor. Once you switch on the button, everything is neatly mixed up. The separate food that was entered into the processor were the data and the mixture after it’s being processed is the useful information that can finally be eaten! The processor of the computer is the CPU and it’s much much smaller than a food processor.
3. Output : The monitor of the computer is one way of displaying output in a computer. The computer gives out information (the data from input which are processed) as output. This output can sometimes make the user frustrated if the computer is not giving the expected results.
4. Storage : The computer can store a huge chunk of data which can bee retrieved at anytime unless the computer breaks down. Just imagine, if computers were invented without any storage capacity, the companies today will have to spend millions on building storage houses for all the office files. They will have to hire more workers to keep the files safe and they will also have to spend on bug sprays to keep the files away from monster bugs!
5. Communication : The computer makes it possible for the users to transfer data from one computer to another through a network. This operation of the computer saves much of our time so that we can spend some hours relaxing only if not for assignments and other daunting tasks.

These are the basic operations of the computers for now. But in future, I believe there will be more. The world is growing fast with technology and in no time, the operations of the computers will exceed the operations of the human body!