Components of Computer PDF

Components of Computer Lesson Objectives: At the end of this lesson, you will be able to: Understand the function of each part of a computer Identify the different input devices Identify the different output devices Have knowledge in computer peripherals A compute...

Components of Computer Lesson Objectives: At the end of this lesson, you will be able to: Understand the function of each part of a computer Identify the different input devices Identify the different output devices Have knowledge in computer peripherals A computer system is made up of a combination of hardware and software. Hardware All of the electronic and mechanical equipment in a computer is called the hardware. Examples include motherboard, hard disk, RAM, power supply, processor, case, monitor, keyboard, mouse. Software The term software is used to describe computer programs that perform a task or tasks on a computer system. Software can be grouped as follows: System software – these are the programs that control the operation of the computer system. Operating systems and utility programs are the most common. Application software - This software is used to do non-system based tasks. Categories include business software, engineering software, medical software, games etc. PC Components A computer system is a collection of electronic and mechanical devices operating as a unit. These devices can be sorted according to the role they play in the computer system. The main device categories are: Input devices These devices are used to get data into the computer system Processing devices These manipulate the data using to a set of instructions called a program Output devices These are used to get data out of a computer system Storage devices These can store the data for use at a later stage Communication devices These can send the data to another computer system TYPES OF STORAGE Lesson Objectives: At the end of this lesson, you will be able to: Familiarize the different types of storage devices Have knowledge in identifying the different storage capacity of a certain storage device Understand and differentiate application software, system software, and web-based software Describe the database and database management Be competent in identifying the storage devices and software Storage is a place where we can store data, files, information, and other important documents we need for future references. There are different storage devices when we speak about technology. Storage may vary on what you are going to store to it. Types of Storage Primary Storage Secondary Storage Tertiary Storage Off-line Storage  Primary Storage - Also known as main memory. - Main memory is directly or indirectly connected to the central processing unit via a memory bus - The CPU continuously reads instructions stored there and executes them as required - Examples: RAM, ROM, Cache o RAM - It is called Random Access Memory because any of the data in RAM can be accessed just as fast as any of the other data - Types of RAM: DRAM (Dynamic Random-Access Memory), SRAM (Static Random Access Memory) Static RAM Dynamic RAM Faster Slower More expensive Less expensive More power consumption Less power consumption Needs to be refreshed thousands of times per second Does not need to be refreshed Dynamic RAM Static RAM o ROM - This memory is used as the computer begins to boot up - Small programs called firmware are often stored in ROM chips on hardware devices (like a BIOS chip), and they contain instructions the computer can use in performing some of the most basic operations required to operate hardware devices - ROM cannot be easily or quickly overwritten or modified o Cache - Is a high-speed access area that can be either a reserved section of main memory or a storage device - Most computers today come with L3 cache or L2 cache, while older computers included only L1 cache  Secondary Storage - It is not directly accessible by the CPU - Computer usually uses its input/output channels to access secondary storage and transfers the desired data using intermediate area in primary storage - Examples: Hard disk o Hard Disk - The hard disk drive is the main, and usually largest, data storage device in a computer - It can store anywhere from 160 gigabytes to 2 terabytes - Hard disk speed is the speed at which content can be read and written on a hard disk - A hard disk unit comes with a set rotation speed varying from 4500 to 7200 rpm - Disk access time is measured in milliseconds  Tertiary Storage - Typically it involves a robotic mechanism which will mount(insert) and dismount removable mass storage media into a storage device - It is a comprehensive computer storage system that is usually very slow, so it is usually used to archive data that is not accessed frequently - This is primarily useful for extraordinarily large data stores, accessed without human operators - Examples: Magnetic Tape, Optical Disc o Magnetic Tape - A magnetically coated strip of plastic on which data can be encoded - Tapes for computers are similar to tapes used to store music - Tape is much less expensive than other storage mediums but commonly a much slower solution that is commonly used for backup o Optical Disc - Any storage media that holds content in digital format and is read using a laser assembly is considered optical media - Most common types of optical media are: Blu-ray (BD), Compact Disc (CD), Digital Versatile Disc (DVD)  Off-line Storage - Also known as disconnected or removable storage - Is a computer data storage on a medium or a device that is not under the control of a processing unit - It must be inserted or connected by a human operator before a computer can access it again - Examples: Floppy Disk, Zip diskette, USB Flash Drive, Memory Card o Floppy Disk - A soft magnetic disk - Floppy disks are portable - Floppy disks are slower to access than hard disks and have less storage capacity, but they are much less expensive - Can store data up to 1.44MB - Two common sizes: 5 ¼” and 3 ½” o Zip Diskette - Hardware data storage device developed by Iomega that functions like a Standard 1.44” floppy drive - Capable to hold up to 100MB of data or 250MB of data on new drives - Now it is less popular as users needed larger storage capabilities o USB Flash Drive - A small, portable flash memory card that plugs into a computer’s USB port and functions as a portable hard drive - Flash drives are available in sizes such as 256MB, 512MB, 1GB, 5GB, and 16GB and are an easy way to transfer and store information o Memory Card - An electronic flash memory storage disk commonly used in consumer electronic devices such as digital cameras, MP3 players, mobile phones, and other small portable devices. Storage Device Features Volatility Accessibility Mutability Addressability  Volatility - Types of volatility: Volatile Memory, Non-volatile memory  Volatility - Types of volatility: Volatile Memory, Non-volatile memory o Volatile Memory - Requires constant power to maintain the stored information. - The fastest memory technologies - All contents are erased when the system's power is turned off or interrupted. - It has been more popularly known as temporary memory. o Non-Volatile Memory - Will retain the stored information even if it is not constantly supplied with electric power - Non-volatile memory is the device which keeps the data even when the current is off - It is suitable for long-term storage of information  Accessibility - Refers to reading or writing data records - Two types of accessibility: Random access, Sequential access o Random Access - Any location in storage can be accessed at any moment in approximately the same amount of time - Such characteristic is well suited for primary and secondary storage. o Sequential Access - The accessing of pieces of information will be in a serial order, one after the other; therefore the time to access a particular piece of information depends upon which piece of information was last accessed. - Such characteristic is typical of off-line storage.  Mutability - Allows information to be overwritten at any time - A computer without some amount of read/write storage for primary storage purposes would be useless for many tasks - Three types of mutability: Read/write storage or mutable storage, Read only storage, Slow write, fast read storage o Read/Write Storage or Mutable Storage - Allows information to be overwritten at any time - A computer without some amount of read/write storage for primary storage purposes would be useless for many tasks o Read Only Storage - Retains the information stored at the time of manufacture, and write once storage (WORM) allows the information to be written only once at some point after manufacture. - These are called immutable storage o Slow Write, Fast Read Storage - Read/write storage which allows information to be overwritten multiple times, but with the write operation being much slower than the read operation.  Addressability - Three types of addressability: Location-addressable, File addressable, Content-addressable o Location-addressable - Each individually accessible unit of information in storage is selected with its numerical memory address. o File addressable - Information is divided into files of variable length, and a particular file is selected with human-readable directory and file names o Content-addressable - Each individually accessible unit of information is selected based on the basis of (part of) the contents stored there - Content-addressable storage can be implemented using software (computer program) or hardware (computer device), with hardware being faster but more expensive option. - Hardware content addressable memory is often used in a computer's CPU cache Other Examples of Storage Device Punch card Cloud storage RAID Punch card - Early method of data storage used with early computers - Punch cards also known as Hollerith cards - Containing several punched holes that represents data Cloud storage - Cloud storage means "the storage of data online in the cloud," wherein a data is stored in and accessible from multiple distributed and connected resources that comprise a cloud. - Cloud storage can provide the benefits of greater accessibility and reliability; rapid deployment; strong protection for data backup, archival and disaster recovery purposes - Examples: Google Drive, Flickr, Microsoft Sky Drive RAID - RAID is short for redundant array of independent (or inexpensive) disks - It is a category of disk drives that employ two or more drives in combination for fault tolerance and performance. - RAID disk drives are used frequently on servers but aren't generally necessary for personal computers - RAID allows you to store the same data redundantly (in multiple paces) in a balanced way to improve overall storage performance.