Hardware
Computer hardware basically refers to the physical aspects of the computer; the computer parts that are tangible and can be touched.
This includes various devices comprising a computer:
Keyboard, screen, mouse, disks, memory, CD-ROM, and processing units
Computer Hardware Components
Ø Input
Keyboard, Mouse, Camera, Touch Pad
Ø Processing
CPU
Ø Output
Monitor, Printer
Ø Storage
Floppy, Hard Drive, CD, DVD, Flash Drive
Hardware Generations
Computer hardware basically refers to the physical aspects of the computer; the computer parts that are tangible and can be touched.
This includes various devices comprising a computer:
Keyboard, screen, mouse, disks, memory, CD-ROM, and processing units
Computer Hardware Components
Ø Input
Keyboard, Mouse, Camera, Touch Pad
Ø Processing
CPU
Ø Output
Monitor, Printer
Ø Storage
Floppy, Hard Drive, CD, DVD, Flash Drive
Hardware Generations
Six Logical units in every computer:
Obtains information from input devices.
Example : Keyboard ,Scanner.
2. Output unit
Outputs information (to screen, to printer, to control other devices)
3. Memory unit
Rapid access, low capacity, stores input information
ROM (Read Only Memory): CMOS, EPROM …
RAM (Random Access Memory): SRAM, DRAM, SIMM, DIMM
4. Arithmetic and logic unit (ALU) – part of CPU
Performs arithmetic calculations (addition, subtraction...) and logic decisions
5. Control unit (CU) - part of CPU
Supervises and coordinates the other sections of the computer
6. Secondary storage unit
Cheap, long-term, high-capacity storage
Stores inactive programs
Computer Architecture
- Input unit
Obtains information from input devices.
Example : Keyboard ,Scanner.
2. Output unit
Outputs information (to screen, to printer, to control other devices)
3. Memory unit
Rapid access, low capacity, stores input information
ROM (Read Only Memory): CMOS, EPROM …
RAM (Random Access Memory): SRAM, DRAM, SIMM, DIMM
4. Arithmetic and logic unit (ALU) – part of CPU
Performs arithmetic calculations (addition, subtraction...) and logic decisions
5. Control unit (CU) - part of CPU
Supervises and coordinates the other sections of the computer
6. Secondary storage unit
Cheap, long-term, high-capacity storage
Stores inactive programs
Computer Architecture
INPUT
· This is the process of computer accepting the data instruction through input device.
· Example: Keyboard,Scanner.
PROCESSING
The process of performing of lesion such as arthimatical and logical operation based on set instruction given.
PROCESSING UNIT
It consists of two parts
The process data from CPU which is in the form of machine level language will be converted into user under stable language and then feed to the output device.
STORAGE UNIT
The Storage Unit is used to store data and information permanently for future retrieval.
SYSTEM UNIT
The System Unit is the core of a computer system. The most important of these component is the Central Processing Unit(CPU) which acts a the brain of the computer.
System components
Component needed to assemble a basic modern PC system.
Motherboard : This is the important component of the computer as everything else is connected to it. And it controls everything in the system. Motherboard are available in several different shapes.This transfers data between all of the computer components.This is the main circuit board that incommended the following
Ø PCI Slots - PCI is Peripheral Component Interconnect.This is used for other devices such as sound card,Modem operates at 33 MHz and has a maximum bandwidth of 133 MB/s.
Ø ISA Slots – ISA is Industry Standard Architecture.It is not used very often with modern motherboards.It operates at 16MHz and has maximum bandwidth of 16 MB/s.
Ø CMOS - This is used to store important system information and configuration settings while the computer is off and on.
Ø Ports
This is used to connect peripheral devices to your computer
Ø Serial Port --This is a serial communication physical interface through which information transfers in or out one bit at a time. The serial port has been replaced by USB in most cases.
Ø Monitor Ports -- Used to connect a monitor to the computer.
Ø Parallel Port -- This interface is found on the back of older PCs and is used for connecting external devices such as printers or a scanners. The parallel port is sometimes called a centronics interface, since Centronics was the company that designed the original parallel port standard. It is sometimes also referred to as a printer port because the printer is the device most commonly attached to the parallel port.
Ø USB Port – Universal Serial Bus. Now used to connect almost all peripheral devices to the computer.
Ø Ethernet Port– This port is used for networking and fast internet connections.
Processor : The processor is often thought as the engine of the computer. This is the Brain of the brain of the computer.Then the processor reads the commands from the memory and then executes them. the processor is one of the most expensive parts of the computers and is also one of the smallest parts.Data processing and execution of data’s is performing in it.
Memory : This used to hold programs and data during execution.
Random Access Memory– RAM.Where information is stored temporarily when a program is run. Information is automatically pulled into memory, we cannot control this. RAM is cleared automatically when the computer is shutdown or rebooted. RAM is volatile.
Read Only Memory– ROM. More permanent than RAM. Data stored in these chips is nonvolatile .it is not lost when power is removed. Data stored in these chips is either unchangeable or requires a special operation to change. The BIOS is stored in the CMOS, read-only memory.
Primary Memory : This is often called as RAM. ). It holds all the programs and data the processor is using at a given time. RAM is volatile
because its contents are erased when power is switched off.
Hard disk : This is also called as Secondary memory. There can be several programs in the system, which cannot be stored in RAM, so we need a very huge non-volatile memory, which can be used for storing all the programs, and data when the system is not in use are called as Hard disks.
CD ROM : CD ROM stands for compact disk read only memory. It consists of small disks similar to the gramophone records to hold digital information. As the name applies they are read only medium. With the advancement in technology writable CD’s are also available.
Floppy Drive : This is the slowest and the smallest form of secondary storage. This provides a simple way to carry information from one place to another, and backup small amount of files.
Keyboard : The keyboard is the main input device for most computers. It is used to input text or enter commands into the PC. Nowadays keyboards with additional features are available like multimedia keyboard, wireless keyboard.
Mouse : The main advantage of mouse over keyboard is simplicity. And there are many operations that are much easier to perform with a mouse then a keyboard. Users simply point and click to enter information.
Monitor : The monitor is the specialized high-resolution screen similar to a television. The actual display screen is made up or red, green and blue dots that are illuminated by electron beam from behind.
· DP- Dot Pitch – Measurement that indicates the diagonal distance between light colored phosphor dots on a display screen.
· This is one of the principle of determining the quality of display of monitors.
· The lower the number the crisper the image.
Two basic Types of Monitors
Ø CRT- Cathode Ray Tube
Ø LCD –Liquid Crystal Display
Ø Both produce sharp images but, LCD monitors have the advantage of being much thinner and lighter
Peripheral Devices : Any external device, which is not necessary to perform the basic operation of computer, is called as peripherals. They provide additional computing capabilities. For ex : Printers, Modems, Speakers etc
Modem : Modem (Modulator and Demodulator) is typically used to send digital data over a phone line.The sending modem converts digital data into analog data, which can be transmitted over telephone lines,and the receiving modem converts the analog data back into digital form. This is used to connect to Internet.
The following characteristics distinguish one modem from another:
Network Interface Card – The most common type of network is a wired network using Ethernet cables and hardware. For this type of network we need to install and configure a network interface card in each of the PCs.
Ø NIC is a card installed in a computer that unable the computer to communicate a network.
Ø Every Client and server must have a network interface card in order to be a part of network.
BIOS
It is a memory (ROM) keeping a group of routines needed to control system devices. It allows booting process. System configuration is saved in a CMOS memory needing a battery not to loose the information.
Caché Memory(L1, L2)
Ø Placed between RAM and Microprocessor.
Ø It is extremely fast but with low capacity and high cost.
Ø L1 is built in the Microprocessor.
Ø L2 can be found on the Main Board.
Ø Volatile (loses data when turned off)
L1 Cache
Ø It is known as Primary cache Memory.
Ø It is built inside the microprocessor.
Ø The size is upto 8 to 64 kb.
L2 Cache
Ø It is known as Secondary Cache Memory.
Ø It is a separate chip on the motherboard.
Ø The sizes is upto 2MB to 3MB.
How Microprocessor Works?
This works on the following ways:
Ø Fetch
Fetch is the process of loading the instruction to be executed from the computer memory.
PreFetching : This is the process of loading the next instruction to be executed.
Ø Decode : This is the process of transferring the data into a coded form that can be understood by the microprocessor.
Ø Execute: This process the data, perform arithmetical and logical operation.
Ø Store: Store the result of execution in the computer memory or resistor.
· This is the process of computer accepting the data instruction through input device.
· Example: Keyboard,Scanner.
PROCESSING
The process of performing of lesion such as arthimatical and logical operation based on set instruction given.
PROCESSING UNIT
It consists of two parts
- Control Unit
- Arthimetical & Logic Unit
- The control unit control the flow of data from various input output devices and internal component.
- ALU performing data processing
- Example –Processor.
The process data from CPU which is in the form of machine level language will be converted into user under stable language and then feed to the output device.
STORAGE UNIT
The Storage Unit is used to store data and information permanently for future retrieval.
SYSTEM UNIT
The System Unit is the core of a computer system. The most important of these component is the Central Processing Unit(CPU) which acts a the brain of the computer.
System components
Component needed to assemble a basic modern PC system.
Motherboard : This is the important component of the computer as everything else is connected to it. And it controls everything in the system. Motherboard are available in several different shapes.This transfers data between all of the computer components.This is the main circuit board that incommended the following
Ø PCI Slots - PCI is Peripheral Component Interconnect.This is used for other devices such as sound card,Modem operates at 33 MHz and has a maximum bandwidth of 133 MB/s.
Ø ISA Slots – ISA is Industry Standard Architecture.It is not used very often with modern motherboards.It operates at 16MHz and has maximum bandwidth of 16 MB/s.
Ø CMOS - This is used to store important system information and configuration settings while the computer is off and on.
Ø Ports
This is used to connect peripheral devices to your computer
Ø Serial Port --This is a serial communication physical interface through which information transfers in or out one bit at a time. The serial port has been replaced by USB in most cases.
Ø Monitor Ports -- Used to connect a monitor to the computer.
Ø Parallel Port -- This interface is found on the back of older PCs and is used for connecting external devices such as printers or a scanners. The parallel port is sometimes called a centronics interface, since Centronics was the company that designed the original parallel port standard. It is sometimes also referred to as a printer port because the printer is the device most commonly attached to the parallel port.
Ø USB Port – Universal Serial Bus. Now used to connect almost all peripheral devices to the computer.
Ø Ethernet Port– This port is used for networking and fast internet connections.
Processor : The processor is often thought as the engine of the computer. This is the Brain of the brain of the computer.Then the processor reads the commands from the memory and then executes them. the processor is one of the most expensive parts of the computers and is also one of the smallest parts.Data processing and execution of data’s is performing in it.
Memory : This used to hold programs and data during execution.
Random Access Memory– RAM.Where information is stored temporarily when a program is run. Information is automatically pulled into memory, we cannot control this. RAM is cleared automatically when the computer is shutdown or rebooted. RAM is volatile.
Read Only Memory– ROM. More permanent than RAM. Data stored in these chips is nonvolatile .it is not lost when power is removed. Data stored in these chips is either unchangeable or requires a special operation to change. The BIOS is stored in the CMOS, read-only memory.
Primary Memory : This is often called as RAM. ). It holds all the programs and data the processor is using at a given time. RAM is volatile
because its contents are erased when power is switched off.
Hard disk : This is also called as Secondary memory. There can be several programs in the system, which cannot be stored in RAM, so we need a very huge non-volatile memory, which can be used for storing all the programs, and data when the system is not in use are called as Hard disks.
CD ROM : CD ROM stands for compact disk read only memory. It consists of small disks similar to the gramophone records to hold digital information. As the name applies they are read only medium. With the advancement in technology writable CD’s are also available.
Floppy Drive : This is the slowest and the smallest form of secondary storage. This provides a simple way to carry information from one place to another, and backup small amount of files.
Keyboard : The keyboard is the main input device for most computers. It is used to input text or enter commands into the PC. Nowadays keyboards with additional features are available like multimedia keyboard, wireless keyboard.
Mouse : The main advantage of mouse over keyboard is simplicity. And there are many operations that are much easier to perform with a mouse then a keyboard. Users simply point and click to enter information.
Monitor : The monitor is the specialized high-resolution screen similar to a television. The actual display screen is made up or red, green and blue dots that are illuminated by electron beam from behind.
· DP- Dot Pitch – Measurement that indicates the diagonal distance between light colored phosphor dots on a display screen.
· This is one of the principle of determining the quality of display of monitors.
· The lower the number the crisper the image.
Two basic Types of Monitors
Ø CRT- Cathode Ray Tube
Ø LCD –Liquid Crystal Display
Ø Both produce sharp images but, LCD monitors have the advantage of being much thinner and lighter
Peripheral Devices : Any external device, which is not necessary to perform the basic operation of computer, is called as peripherals. They provide additional computing capabilities. For ex : Printers, Modems, Speakers etc
Modem : Modem (Modulator and Demodulator) is typically used to send digital data over a phone line.The sending modem converts digital data into analog data, which can be transmitted over telephone lines,and the receiving modem converts the analog data back into digital form. This is used to connect to Internet.
The following characteristics distinguish one modem from another:
- BPS – How fast the modem can transmit and receive data.The fastest modem runs at 57,600 bps.
- Voice/Data – Many modem support a switch to change between voice and data modes.In data mode, the modem acts like a regular modem.In voice mode,the modem acts like a regular telephone.
- Data Compression – Some modems perform data compression, which enables them to send data at faster rates.
- Fax Capability – Most modern modems are fax modems, which means that they can send and receive faxes.
Network Interface Card – The most common type of network is a wired network using Ethernet cables and hardware. For this type of network we need to install and configure a network interface card in each of the PCs.
Ø NIC is a card installed in a computer that unable the computer to communicate a network.
Ø Every Client and server must have a network interface card in order to be a part of network.
BIOS
It is a memory (ROM) keeping a group of routines needed to control system devices. It allows booting process. System configuration is saved in a CMOS memory needing a battery not to loose the information.
Caché Memory(L1, L2)
Ø Placed between RAM and Microprocessor.
Ø It is extremely fast but with low capacity and high cost.
Ø L1 is built in the Microprocessor.
Ø L2 can be found on the Main Board.
Ø Volatile (loses data when turned off)
L1 Cache
Ø It is known as Primary cache Memory.
Ø It is built inside the microprocessor.
Ø The size is upto 8 to 64 kb.
L2 Cache
Ø It is known as Secondary Cache Memory.
Ø It is a separate chip on the motherboard.
Ø The sizes is upto 2MB to 3MB.
How Microprocessor Works?
This works on the following ways:
Ø Fetch
Fetch is the process of loading the instruction to be executed from the computer memory.
PreFetching : This is the process of loading the next instruction to be executed.
Ø Decode : This is the process of transferring the data into a coded form that can be understood by the microprocessor.
Ø Execute: This process the data, perform arithmetical and logical operation.
Ø Store: Store the result of execution in the computer memory or resistor.
RAM (Random Acces Memory)
Ø Stores data temporarily.
Ø Higher capacity (Mbytes), cheaper and slower than
Caché.
Ø Need a refresh not to loose data.
Ø Volatile (loses data when turned off).
Ø If the computer doesn’t have enough RAM to run an application than pieces of the running application will be stored on the hard disk drive temporarly in a method known as “Virtual Memory” and the CPU will then have to retrieve information from the virtual memory causing a bottleneck in the system.
Types of RAM
ROM (Read Only Memory)
Ø No-Volatile
Ø ROM is permanent memory.
Ø it never loses what is stored in it.
Ø It can’t load new programs or new data into it, if any important information could be lost.
Microprocessor
Ø Also known as CPU (Central Processing Unit).
Ø Processes the data arriving from storage units and peripherials.
Ø Responsible for running the computer system with speed and efficiency.
Ø Stores data temporarily.
Ø Higher capacity (Mbytes), cheaper and slower than
Caché.
Ø Need a refresh not to loose data.
Ø Volatile (loses data when turned off).
Ø If the computer doesn’t have enough RAM to run an application than pieces of the running application will be stored on the hard disk drive temporarly in a method known as “Virtual Memory” and the CPU will then have to retrieve information from the virtual memory causing a bottleneck in the system.
Types of RAM
- SRAM –Static Random Access Memory
- DRAM – Dynamic Random Access Memory a type of memory used in most personal computers
- SDRAM - Synchronous DRAM .This can run at much higher speed than a conventional memory.This actually synchronizes itself with cpu’s bus.
- DDR SDRAM - Double Data Rate- Synchronous DRAM.This is a type of SDRAM that supports data transfer on both sides effectively doubling the memory chip’s data through out.This consumes less power.
ROM (Read Only Memory)
Ø No-Volatile
Ø ROM is permanent memory.
Ø it never loses what is stored in it.
Ø It can’t load new programs or new data into it, if any important information could be lost.
Microprocessor
Ø Also known as CPU (Central Processing Unit).
Ø Processes the data arriving from storage units and peripherials.
Ø Responsible for running the computer system with speed and efficiency.
Modern Microprocessors work at two different speeds:
Ø Internal: the speed at which data can be processed.
Ø External: the speed used to communicate with Main Board.
Inside Component of Microprocessor
Transistor
· It is the basic component of microprocessor.
· Transistors are act as on/off switch inside the microprocessor.
Clock
· This is the internal component of microprocessor’s which measures the speed at which the microprocessor executes the instruction.This is called clock speed.
· Clock speed is measured in terms of MHz or GHz.
Integrated Circuit
· An IC is an electronic device in which large circuit is suppressed into a small circuit.
· An IC consists of transistor, register,and other elements.
Resistors
· The resistors are the local storage area of microprocessor.
· The resistor holds the data’s while the microprocessor works on a task.
BIU – Bus Interface Unit
It is the component of the microprocessor that helps the microprocessor that helps the microprocessor to communicate with the rest part of the computer.
Hard Disk Drives
The hard disk permanently stores all the important data.Some hard disk can store more than 100 gigabytes of data.
RPM – Revolutions per Minute.This determines how fast your hard drive will access the data.
Typical RPM Values
Desktop Machine – 7200 RPM
Laptop Machine – 5000 RPM
Server Machine – 10000 RPM
ATA – Advanced Technology Attachment
Serial ATA - This is the new way of connecting the hard drives to pc. An evolution of the parallel ATA physical storage interface.Transfer rates for serial ATA begin at 150MBps.This drives have the capability of being faster than the IDE counterparts and also have small thinner cables which help with the airflow of the system.
SCSI – Small Computer System Interface pronounced as scuzzy.This is a parallel interface standard used by Apple Macintosh Computers,PCs and many unix systems.
Video Cards
A board that plugs into a personal computer AGP port on the motherboard to give it display capabilities.
A Printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper.
The four printer qualities of most interest to most users are:
InkJet Printers
These are the most popular printers.This can print in both black&white and color and can produce high quality photographs when used with special paper.
Laser Printers
These are faster and generally better able to handle heavy use.
UPS – Uninterruptable Power Supply
This is a power supply that includes a battery to maintain power in the event of a power outage.A UPS keeps a computer running for several minutes after a power outage, enabling to save data that is in RAM and shut down the computer gracefully.
Two Basic Types of UPS
Scanner is a device which is used to convert the Analog data to digital data.Means hardcopy to soft copy.
Speaker
Speakers are used to play sound.They can be built into the system unit or connected with cables.
Firmware
Firmware is a combination of software and hardware.Computer chips that have data or programs recorded on them are firmware.These chip commonly includes:
Ø ROM –Read Only Memory
Ø PROM – Programmable Read Only Memory
Ø EPROM – Erasable Programmable Read only Memory.
Ø Example : BIOS
Types of Communication
Ø Serial Communication
Serial Communication is the process of sending data one bit at a time,sequentially,over a communication channel or computer bus.
Ø Parallel Communication
Parallel communication is a method of conveying multiple binary digits simultaneously.
Ø Internal: the speed at which data can be processed.
Ø External: the speed used to communicate with Main Board.
Inside Component of Microprocessor
Transistor
· It is the basic component of microprocessor.
· Transistors are act as on/off switch inside the microprocessor.
Clock
· This is the internal component of microprocessor’s which measures the speed at which the microprocessor executes the instruction.This is called clock speed.
· Clock speed is measured in terms of MHz or GHz.
Integrated Circuit
· An IC is an electronic device in which large circuit is suppressed into a small circuit.
· An IC consists of transistor, register,and other elements.
Resistors
· The resistors are the local storage area of microprocessor.
· The resistor holds the data’s while the microprocessor works on a task.
BIU – Bus Interface Unit
It is the component of the microprocessor that helps the microprocessor that helps the microprocessor to communicate with the rest part of the computer.
Hard Disk Drives
The hard disk permanently stores all the important data.Some hard disk can store more than 100 gigabytes of data.
RPM – Revolutions per Minute.This determines how fast your hard drive will access the data.
Typical RPM Values
Desktop Machine – 7200 RPM
Laptop Machine – 5000 RPM
Server Machine – 10000 RPM
ATA – Advanced Technology Attachment
Serial ATA - This is the new way of connecting the hard drives to pc. An evolution of the parallel ATA physical storage interface.Transfer rates for serial ATA begin at 150MBps.This drives have the capability of being faster than the IDE counterparts and also have small thinner cables which help with the airflow of the system.
SCSI – Small Computer System Interface pronounced as scuzzy.This is a parallel interface standard used by Apple Macintosh Computers,PCs and many unix systems.
Video Cards
A board that plugs into a personal computer AGP port on the motherboard to give it display capabilities.
- Modern video adapters contain memory,so that the computer’s RAM is not used for storing displays.
- It have their own graphics coprocessor for performing graphics calculations.These adapters are called graphic accelerators.
A Printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper.
The four printer qualities of most interest to most users are:
- Color: Color is important for users who need to print pages for presentations or maps and other pages where color is part of the information. Color printers can also be set to print only in black-and-white. Color printers are more expensive to operate since they use two ink cartridges (one color and one black ink) that need to be replaced after a certain number of pages. Users who don't have a specific need for color and who print a lot of pages will find a black-and-white printer cheaper to operate.
- Resolution: Printer resolution is usually measured in dots per inch ( dpi ).This refers to the sharpness and clarity of an image. Most inexpensive printers provide sufficient resolution for most purposes at 600 dpi.
- Screen Resolution: This signifies the number of dots on the entire screen.
- PPM : Page Per Minute used to measure the speed of certain types of printers.This measurement is for TEXT and NOT Graphics.
- Speed: If you do much printing, the speed of the printer becomes important. Inexpensive printers print only about 3 to 6 sheets per minute. Color printing is slower. More expensive printers are much faster.
- Memory: Most printers come with a small amount of memory (for example, one megabyte) that can be expanded by the user. Having more than the minimum amount of memory is helpful and faster when printing out pages with large images or tables with lines around them (which the printer treats as a large image).
InkJet Printers
These are the most popular printers.This can print in both black&white and color and can produce high quality photographs when used with special paper.
Laser Printers
These are faster and generally better able to handle heavy use.
UPS – Uninterruptable Power Supply
This is a power supply that includes a battery to maintain power in the event of a power outage.A UPS keeps a computer running for several minutes after a power outage, enabling to save data that is in RAM and shut down the computer gracefully.
Two Basic Types of UPS
- Standby Power Systems(SPS) – Monitors the power line and switches to battery power as soon as it detects a problem.
- Online UPS Systems – Provides constant power from its own converter.
Scanner is a device which is used to convert the Analog data to digital data.Means hardcopy to soft copy.
Speaker
Speakers are used to play sound.They can be built into the system unit or connected with cables.
Firmware
Firmware is a combination of software and hardware.Computer chips that have data or programs recorded on them are firmware.These chip commonly includes:
Ø ROM –Read Only Memory
Ø PROM – Programmable Read Only Memory
Ø EPROM – Erasable Programmable Read only Memory.
Ø Example : BIOS
Types of Communication
Ø Serial Communication
Serial Communication is the process of sending data one bit at a time,sequentially,over a communication channel or computer bus.
Ø Parallel Communication
Parallel communication is a method of conveying multiple binary digits simultaneously.