Computer hardware
Computer hardware is the physical component of computers and related devices. There are four types of devices as the followings:
• Input devices
• Processing devices
• Output devices
• Storage devices
Input devices
Input devices are pieces of equipment that are used to put the information or instructions into a computer. Input devices allow us to enter raw data into a computer; the computer processes the information and then produces outputs that we can understand using output devices. For example: Key board, Mouse/pointing devices/ joystick, Stylus, Scanner, Digital camera, Microphone…
There are many ways to input data into computer by using different of input devices that are present as the followings:
Entering the text and numbers
The keyboard is a tool to input letters or numbers into different applications or programs. Also, it has special keys that help operate the computer. There are three types of keyboard such as traditional, Ergonomic, and virtual.
Pointing and Selecting Devices
There are many tools for pointing and selecting in different programs such as Microsoft Office, Web page, etc. These are some devices to use for pointing and selecting.
| Devices | Description |
|---|---|
| Mouse | Pointing device that works by sliding box-like devices on flat surface. Selections are made by clicking button on the mouse |
| Trackball | Pointing device that works by rolling a ball that sit in a holder. Select ones are made by pressing buttons-located near or on the holder |
| Joystick | Pointing device that works by moving a small stick that sit in the holder. Selections are made by pressing buttons-located near or on the holder |
| Touch screen | Pointing device that works by using a touch sensitive computer display. Selections are made by touching the display |
| Light pen | Pointing device that works by placing a ball-light device near a computer screen. Selections are made by pressing the pen in the screen |
Entering Batch Data
Entering Batch Data is the inputting information of things in batch into our computers by scanning.
Scanning Technologies
There are many types of scanners that are the followings:
| Scanner | Description |
|---|---|
| Optical Mark Recognition (OMR) | Used to scan questionnaires and test answer forms (bubble paper) where answer choices are marked by filling in circle using pen or pencil |
| Optical Character Recognition (OCR) | Used to read and digitize typewritten, computer print, and even hand written character such as on sale tags on department store merchandise, patient information in hospitals or address information on a piece of postal mail |
| Bar code reader | Used mostly in grocery stores and other retail businesses to read bar code data at the check-out counter, also used by libraries |
| Magnetic Ink Character Recognition (MICR) | Used by banking industry to read data, account numbers, bank codes, and check numbers on preprinted checks |
| Biometric Scanner | Used to scan human body characteristics of users to enable everything from secure access to payment procurement |
Audio Input
Audio can be digitized and voice can be input to the computer by using Microphone, Speech recognition, and Voice-to-text software or we can copy from another device.
Video Input
Video can be input to the computer by using digital cameras or web cam that built in notebook.
Binary Language
Binary language is kind of computer language that consists of two numbers: 0 and 1. Everything a computer does is broken down into a series of 0s and 1s. For example, Switches are devices inside the computer that can be flipped between these two states: 1 and 0, on or off.
Switches
Switches are non-mechanical devices in computers that open and close circuits. There are many types of switches such as Vacuum tubes, Transistors, and Integrated circuits.
Switches Representing Data
o The on/off state of a switch represents one bit of data.
o Bit (binary digital)
o On = 1, off = 0
System Unit
System Units are those of systems that work in the internal of computer. There are many tools such as
o Mother board, power supply, and fan
o Central processing unit
o RAM and ROM memory
o Hard drive, CD-ROM or DVD ROM
o Ports for plugging in peripherals
Inside System Unit
The front Panel
The Back Pannel
Motherboard
Central Processing Unit (CPU)
CPU is the brain of the computer that controls all functions of the computer. It processes all commands and instructions that can perform billions of tasks per second. At present, Intel is the biggest company produces CPU for most of computer brand.
Expansion Cards
Expansion cards are the cards that add more functions and provide new connections for peripheral devices that consists of sound, modem, video (VGA), and Network (NIC).
Video Card
Video card is an expansion card that process binary data into images. It controls the number of colors that display on monitors.
Graphics Processing Unit (GPU)
GPU performs the same work as a CPU. It helps CPU to handle graphics that allow our computer be able to run hard software such as game 3D that need high CPU and GPU.
Sound Cards
Sound Card is a card that attach in motherboard. It processes the digital data into sounds.
Buses
Buses are the CPU’s data highway that used to move data between components.
Ports
Ports are used to connect peripheral devices to the computer such as speaker phone, keyboard, mouse, thumb drives, telephone, printer, monitor…
There are many types of port that are the followings:
• Universal Serial Bus (USB): USB Port and USB connector.
• FireWire: FireWire Port and FireWire Connector
• Ethernet: Ethernet port and Ethernet Jack
• DVI, Super VGA, S-Video
o DVI is the port that plugging the digital LCD monitors
• Parallel:
o Transfers 8 bits of data simultaneously
o Max speed: 12 Mbps
o Plugging high
• Bluetooth:
o Transfer rate of 1 Mbps to 3 Mbps
o Radio waves send data over short distances
Port Summary
| Port name | Used to Connect | Description |
|---|---|---|
| Serial | Modem, mice, keyboard, terminal display, MIDI, Printer | • Used to one bit at a time • Slowest data transfer rates |
| USB (Universal Serial Bus) | Printer, scanner, mice, keyboard, digital camera and camcorders, external disk drives | • A very high speed data transfer method • Up to 480 million bytes per second • Up to 127 devices simultaneously connected |
| IEEE 1394 (“Fire Wire”) | Digital camera and camcorders, external disk devices | • Extremely high speed data transfer method • Up to 800 million bytes per second • Up to 63 devices simultaneously connected |
Storage Devices
There are 2 types of storage devices:
1. Primary Storage can store the data temporary when the computer is turned on. It helps supporting computer processing. The components of primary storage are RAM (Random-access memory), ROM (Read-only memory) and Cache memory.
- RAM: Every data that is first opened on the computer will be store in RAM. However, it is volatile because when the computer is turned off, the memory will be lost. RAM is the computer’s main or primary memory and very important for the performance of the computer because it reflects the efficiency or speed when opening the applications. Therefore, you have to have enough RAM to open the application according to its requirement such as, running Windows Vista Home Basic, you have to have at least 512 MB RAM in your computer. If you do not have enough RAM, your computer will be freeze.
- ROM: Store data that is used for booting computer and store BIOS (Basic input/output system) meaning that when you open your computer, it will read the data from ROM first and it is nonvolatile or permanent on your computer. Also, it can be read but cannot be written to.
- Cache memory: When the data is taken from hard disk and then from RAM, it has to store at cache memory before it can be processed. It is the storage for the most recently or most frequently used data.
2. Secondary Storage can keep the data when the computer is turned off. For example, Hard disk, Thumb drive, CD-Rom. It is nonvolatile and can store the data permanently.
- Hard Drives store data in the several magnetic disks which has high storage capacity and read/write heads.
- Optical Disks are any types of data which have to use laser beam technology to read and write.
o CD-ROMs (Compact disc-read-only memory) there are 2 kinds of CD-ROMs which are CD-R (Compact disc-Recordable) and CD-RW (Compact Disc ReWritable)
o DVD-ROM (Digital versatile disk-read-only memory): It uses shorter-wavelength laser beam. A few years ago, the development of DVD leads to the battle between HD-DVD and Blu-Ray then the winner right now is Blu-ray.
- Flash Drives/ Flash Memory
o Flash Drives are newer storage alternative which can be easily connect through the computer by plugging into USB ports and become necessary tools for everyone nowadays.
o Flash Memory Cards use by sliding into slots in the system.
- Output Devices is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.
o CRT(Cathode Ray Tube) and LCD(Liquid Crystal Display)
CRT is less expensive and offers better viewing angles but uses much more space and more energy.
LCD is more expensive and has less viewable from an angles but uses far less space and more energy efficient.
o Touch-screen monitors can be both input and output devices
o Data Projectors can project a computer image to a large screen for sharing with large groups.
- Printers
o Impact printers (Dot-matrix printer) is the printer with a print head that runs back and forth, or in an up and down motion which now become legacy technology.
o Nonimpact printers
Inkjet can operate by propelling variably-sized droplets of liquid or molten material (ink) onto almost any sized page. Inkjet is less expensive device and can print high quality color images cost effectively.
Laser can rapidly produces high quality text and graphics on plain paper. Laser is more expensive device and has faster printing speed but less expensive per page in B&W. Also, the color lasers are becoming less expensive.
o Specialty printers
Multifunction
Plotters
Thermal printer
- Outputting Sound are things we use to get audio out of a computer.
There are 2 terms of technology that are necessary to know:
o Legacy Technology means no longer used, used to be popular in the past or has been replaced with Disruptive Technology for example, CRT (Cathode Ray Tube), LCD (Liquid Crystal Display) is used instead of CRT, Tape cassette, Floppy Disk, Walk-man, Soundabout, Film-based camera, Fixed phone, Thumbdrive (Use online storage instead).
o Disruptive Technology is emerging technology that becomes the standard technology for example, Blu-Ray, iPhone and Blackberry (according to the research the majority of the users consume data more than voice. It means that mobile phone users have changed habit from consuming data to voice), Social Media (Facebook helps emerging community), Wi-max (Wireless area for metropolitan which might replaces wi-fi because it can cover the area up to 50 kilometers of the city but wi-fi can cover only 100 feet). Therefore, if the company wants to be success earlier than the competitors, it should be the first mover that adopts disruptive technology in the industry such as Google, Facebook. They are the first mover that can define disruptive technology and adopt this in their business model
Types of Computer
• Supercomputers
o Users: 1-to-many
o Size: Automobile—multiple rooms
o Typical use: Scientific research
o Memory: 5000+ GB
o Cost: $1-20 million
They are high price (more than $20 million) and have very high processing power. It is used to process only for a certain application which involves with high complicated factors such as, earthquake forecasting, projects that analyze radio wave to look for E.T. in the universe. Now, the fastest computer belongs to IBM (last year, the fast one belonged to Japanese company).
• Mainframe
o Users: 1000+
o Size: Refrigerator
o Typical use: Large general purpose business and government
o Memory: Up to 1500+ GB
o Cost: $1-10 million
It is being used almost 60 years ago. Nowadays, it is used as a server to share data in the big company for large general purpose such as government. Its price is up to $10 million.
• Midrange Computers (Mini Computer)
o Users: 5-500
o Size: File cabinet
o Typical use: Midsize general purpose business
o Memory: Less than 20 GB
o Cost: $10,000-100,000
They are also used as a server of the organization. Its cost is lower than Mainframe ($100,000).
• Microcomputers or PCs
o Users: 1
o Size: Handheld—fitting on desktop
o Typical use: Personal productivity
o Memory: 512 MB – 2 GB
o Cost: $200 – 5,000
Its cost nowadays is very cheap. The high-end PC costs around $1,000.
• Network Computers (Thin Clients) are the computers that attach to the network which have minimal memory and storage. Every data is being processed and kept at the server such as, ATM which can reduce the cost of the organization to use as the product display or terminal that use only input data since it helps reducing obsolescence and maintenance. It is not necessary to use high-end PC as the network computers because the server is responsibility all the processing data and storage.
• Portable Computers (Notebooks/ Laptops) The criteria that people considers when buying this type of computer are:
o Light weight
o Battery life such as Macbook Pro has 9 hours battery life which can be used on the plane.
o Limited expandability
o Docking Station
Other criteria are price, processing power which is no longer the main criteria.
• Tablet PCs can accept input from an electronic pen and might become disruptive technology soon because the future technology will involve a lot with multi-touch interface. There are 2 versions:
o Convertible model can input data via pen or keyboard.
o Slate model has no keyboard.
• Handheld Computer nowadays it combines the function with the mobile phone such as Blackberry and iPhone which also can access through the internet just like other types of computers
The different points between Desktop and Notebook
• Desktop is hard to move around, less expensive, harder to steal and easier to upgrade but it is difficult to ship or repair.
• Notebook is portable, more expensive. Therefore, it can be easily stolen. It is also difficult to upgrade and prone to damage.
Notebook is easier to stolen. Therefore, there is a website that offers the users to register and helps them when their notebooks are stolen by turning on the front camera to capture the stealer or location and sending the picture to the owner e-mail. However, mostly, the data in the computer is much more important than the value of the computer. That is why, the users may have to backup the important data in several places such as online storage.
Era of IT Infrastructure
• Mainframe Era/ Mini Computer (1959 – present): Mainframe computer is used in the big organization.
• Personal Computer (1981 – present) becomes popular when Bill Gates and Steve Jobs came out. Then the Wintel standard is occurred which means the computer that have Windows operating system and Intel CPU. It becomes standard of the market which covers almost 90% of the PC market.
• Client Server (1983 – present): In 1970, there is TCP/IP standard which is server era involves with the internet. There are server computer and client.
• Enterprise Internet (1992 – present): After 1990, internet becomes famous. The organizations connect through the internet to do the transaction.
• Cloud Computing (2000 – present) is the present age that means resources and services can be connect through the internet such as the storage service, software application service. This can change to the new paradigm of acquiring the resources for example, software that can be rent over the internet.
Key Drivers.
• Moore’s Law describes a long-term trend in the history of computing hardware, in which the number of transistors that can be placed inexpensively on an integrated circuit has doubled approximately around 18 months or every two years. It involves with Nanotechnology that can shrink size of transistors to width of several atoms. However, there are contrary factors about heats dissipation needs, power consumption concerns.
Credit: Wikipedia.com
• Law of Mass Digital Storage: According to the high growth of e-business, it is clearly seen that the amount of data such as Google increases in double every year. Fortunately, the cost of storing data is declining and also the capability of hard disk is expanding. Such as, the capability of thumb drive in the past was 4 GB or 8 GB but nowadays it is increased to 32 GB. Therefore, there will be the possibility to get thumb drive that has 64 GB next year. About the hard disk, there is 1 trillion byte of hard disk. These are the trend of the data storage. In Thailand, it becomes the target destination for hard disk manufacturer which is now the first exporter such as Seagate, Hitachi which invest the manufacturers in Thailand.
• *Final Exam* Metcalfe’s Law and network economics (Network effect) is one of the key success factors of the company meaning that the value or power of a network grows exponentially as a function of the number of network members. The value of the network is determined by the number of the participant which can affect the success of many businesses that have a lot of participant such as Ebay (there are many sellers and buyers), Microsoft (majority of PC users use), Facebook (because a lot of your friends use it), Youtube (many people connect to Youtube). Therefore, any companies which can expand the network effect will become the winner. Normally, it is benefit for the first mover because if the company wants to catch the disruptive technology, it has to create network affect hurry. That is why, many companies offer the free service at first because they want to build the network effect. Then after that they can think of revenue model such as Google which give free search engine service to create network effect and think about revenue model later, Facebook is also free service but has some revenue model behind as an advertising.
• Exponential Declines in Internet Communication Costs: Fortunately, the cost of communication is declining in this age of internet. Nowadays, people who have internet access are estimated to 1.5 billion people worldwide and the majority is in Asia (only China has 200 million internet users). In some countries, they provide public internet for free such as in Philadephia. The cost of accessing the internet is declining comparing to the past that the cost was very expensive even in the dial connection. In Korea, 90% of the households have broadband internet (cost around only 300 baht which is much cheaper in Thailand). For Thailand, there are only 16 million people who can access the internet (out of 65 million populations).
• *Final Exam* Standard of network effect: In network effect, you have to set the right standard for the industry. Technology standards are specifications that establish the compatibility of products and the ability to communicate in a network which can unleash powerful economies of scale and result in price declines as manufacturers focus on the products built to a single standard.
• Total Cost of Ownership of Technology Assets (TCO): When you invest in the IT industry, you have to consider TCO model which is used to analyze direct and indirect costs of systems for your account which are:
o the cost of acquiring software and hardware is 20% of TCO
o Other costs (Ongoing cost) are the majority of the cost which are the installation, training, support, maintenance, infrastructure, downtime, space and energy.
TCO can be reduced through greater centralization and standardization of hardware and software resources.
