Storage devices

This copy is from: http://www.dineshbakshi.com/igcse-gcse-ict/storage-devices-and-media

What are Storage devices?

Storage Devices are the data storage devices that are used in the computers to store the data. The computer has many types of data storage devices. Some of them can be classified as the removable data Storage Devices and the others as the non removable data Storage Devices. 

The memory is of two types; one is the primary memory and the other one is the secondary memory.

The primary memory is the volatile memory and the secondary memory is the non volatile memory. The volatile memory is the kind of the memory that is erasable and the non volatile memory is the one where in the contents cannot be erased. Basically when we talk about the data storage devices it is generally assumed to be the secondary memory.

The secondary memory is used to store the data permanently in the computer. The secondary storage devices are usually as follows: hard disk drives – this is the most common type of storage device that is used in almost all the computer systems. The other ones include the floppy disk drives, the CD ROM, and the DVD ROM. The flash memory, the USB data card etc.

Find out more ... Navigate through the list of storage devices given on the right side.

Floppy discs

A floppy disk is a data storage medium that is composed of a disk of thin, flexible floppy)magnetic storagemedium encased in asquareor rectangularplasticshell. Floppy disks are read and written by afloppy disk drive.

Application

Any use where small files such as word processing, small spreadsheets and databases need to be moved from one computer to another.
Useful to backup small data files.

Fixed hard discs

A hard disk drive is the device used to store large amounts of digital information in computers and related equipment like iPods and games consoles such as the Xbox 360 and PS3.
Hard disk drives are used to store operating systems, software and working data.
These are suitable for any application which requires very fast access to data for both reading and writing to. However, Hard disk drives may not be suitable for applications which need portability.
Almost all computers used a fixed hard disc. Used for on-line and real time processes requiring direct access. Used in file servers for computer networks to store large amount of data.

Portable hard discs

Portable hard discs are good fun because you can carry data about all over the place and transfer information, programs, pictures, etc between computers.

Advantages:

• Greatly improved data cargo carrying capacity (relative to the 1.44 Mb floppy disc).
• You don't need to worry about the other person having the same type of special cartridge drive as yourself.

Disadvantages:

• Hard drives have to be handled quite carefully, and when being transported should be wrapped in something soft and put in a padded bag.
• More expensive than other forms of removable media.

Application

Portable disc discs are used to store very large files which need transporting from one computer to another and price is not an issue.

Magnetic tapes

Magnetic tape has been used for data storage for over 50 years. When storing large amounts of data, tape can be substantially less expensive than disk or other data storage options. Tape storage has always been used with large computer systems. Modern usage is primarily as a high capacity medium for backups and archives.  

Drawbacks

Writing and retrieving data is slow.
It uses serial access for reading and writing.

Application

Magnetic tapes are used for application which requires extremely large storage capacity where speed of access is not an issue.
It is commonly used for backups of file servers for computer networks, in a variety of batch processing applications such as reading of bank cheques, payroll processing and general stock control.

Optical backing storage media such as CDs andDVDs

• CDs tend to be used for large files (but smaller than 1Gb) which are too big for a floppy disc to hold such as music and general animation.
• DVDs are used to hold very large files (several Gb) such as movie films. Both CDs and DVDs are portable i.e. they can be transported from one computer to another. Both can be used to store computer data.
• CD ROM/DVD ROM Applications which require the prevention of deletion of data, accidental or otherwise. CDs used by software companies for distributing software programs and data; by Music companies for distributing music albums and by book publishers for distributing encyclopaedias, reference books etc. DVDs used by film distributors.
• CD R/DVD R Applications which require a single ‘burning’ of data, e.g. CDs - recording of music downloads from the Internet, recording of music from MP3 format, recording of data for archiving or backup purposes. DVDs – recording of film movies and television programs.
• CD RW/DVD RW Applications which require the updating of information and ability to record over old data. Not suitable for music recording but is very useful for keeping generations of files. DVDs have between five and ten times the capacity of CDs.

Solid state backing storage

• These are the smallest form of memory available in the market today.
• Widely used as removable storage.
• They are more robust than other forms of storage.
• Though expensive than other forms they can be easily written to and updated.

Memory sticks/Pen drives

USB flash drives are typically removable and rewritable, much smaller than a floppy disk. Storage capacities typically range from 64 MB to 64 GB. USB flash drives offer potential advantages over other portable storage devices, particularly the floppy disk.
They have a more compact shape, operate faster, hold much more data, have a more durable design, and operate more reliably due to their lack of moving parts. Flash drives are widely used to transport files and backup data from computer to computer.

Flash memory cards

A memory card or flash memory card is a solid-state electronic flash memory data storage device used with digital cameras, handheld and Mobile computers, telephones, music players, video game consoles, and other electronics.
Nowadays, most new PCs have built-in slots for a variety of memory cards; Memory Stick, CompactFlash, SD, etc. Some digital gadgets support more than one memory card to ensure compatibility.

motherboard

MOTHERBOARD

this copy is from: http://www.webopedia.com/TERM/M/motherboard.html

The main circuit board of a microcomputer. The motherboard contains theconnectors for attaching additional boards. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial andparallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the motherboard's chipset.

On most PCs, it is possible to add memory chips directly to the motherboard. You may also be able to upgrade to a faster PC by replacing the CPU chip. To add additional core features, you may need to replace the motherboard entirely.

Motherboard is sometimes abbreviated as mobo.

PROCESSOR

PROCESSOR

This copy is from: http://www.techterms.com/definition/processor

A processor, or "microprocessor," is a small chip that resides in computers and other electronic devices. Its basic job is to receive input and provide the appropriate output. While this may seem like a simple task, modern processors can handle trillions of calculations per second.

The central processor of a computer is also known as the CPU, or "central processing unit." This processor handles all the basic system instructions, such as processing mouse and keyboard input and running applications. Most desktop computers contain a CPU developed by either Intel or AMD, both of which use the x86 processor architecture. Mobile devices, such as laptops and tablets may use Intel and AMD CPUs, but can also use specific mobile processors developed by companies like ARM or Apple.

Modern CPUs often include multiple processing cores, which work together to process instructions. While these "cores" are contained in one physical unit, they are actually individual processors. In fact, if you view your computer's performance with a system monitoring utility like Windows Task Manager (Windows) or Activity Monitor (Mac OS X), you will see separate graphs for each processor. Processors that include two cores are called dual-core processors, while those with four cores are called quad-core processors. Some high-end workstations contain multiple CPUs with multiple cores, allowing a single machine to have eight, twelve, or even more processing cores.

Besides the central processing unit, most desktop and laptop computers also include a GPU. This processor is specifically designed for rendering graphics that are output on a monitor. Desktop computers often have a video card that contains the GPU, while mobile devices usually contain a graphics chip that is integrated into the motherboard. By using separate processors for system and graphics processing, computers are able to handle graphic-intensive applications more efficiently.

Random access memory -RAM

RAM - random access memory

This copy is from: http://www.webopedia.com/TERM/R/RAM.html

RAM (pronounced ramm) is an acronym for random access memory, a type ofcomputer memory that can be accessed randomly; that is, any byte of memory can be accessed without touching the preceding bytes. RAM is the most common type of memory found in computers and other devices, such asprinters.

Types of RAM

There are two different types of RAM:

• DRAM (Dynamic Random Access Memory)
• SRAM (Static Random Access Memory)
• 
  

The two types of RAM differ in the technology they use to hold data, with DRAM being the more common type. In terms of speed, SRAM is faster. DRAM needs to be refreshed thousands of times per second while SRAM does not need to be refreshed, which is what makes it faster than DRAM.

DRAM supports access times of about 60 nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite SRAM being faster, it's not as commonly used as DRAM because it's so much more expensive. Both types of RAM are volatile, meaning that they lose their contents when the power is turned off.

RAM, Main Memory and ROM Explained

In common usage, the term RAM is synonymous with main memory, the memory available to programs. For example, a computer with 8MB RAM has approximately 8 million bytes of memory that programs can use. In contrast,ROM (read-only memory) refers to special memory used to store programs that boot the computer and perform diagnostics. Most personal computershave a small amount of ROM (a few thousand bytes). In fact, both types of memory (ROM and RAM) allow random access. To be precise, therefore, RAM should be referred to as read/write RAM and ROM as read-only RAM.

what is computer all about :-0

COMPUTER.

this copy is from: http://www.webopedia.com/TERM/C/computer.html

What is a Computer?

A computer is a programmable machine. The two principal characteristics of a computer are: it responds to a specific set of instructions in a well-defined manner and it can execute a prerecorded list of instructions (a program).

Modern Computers Defined

Modern computers are electronic and digital. The actual machinery -- wires,transistors, and circuits -- is called hardware; the instructions and data are called software.

All general-purpose computers require the following hardware components:

memory: enables a computer to store, at least temporarily, data and programs.

mass storage device: allows a computer to permanently retain large amounts of data. Common mass storage devices include disk drives and tape drives.

input device: usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.

output device: a display screen, printer, or other device that lets you see what the computer has accomplished.

central processing unit (CPU): the heart of the computer, this is the component that actually executes instructions.

In addition to these components, many others make it possible for the basic components to work together efficiently. For example, every computer requires a bus that transmits data from one part of the computer to another.

Computer Classification, By Size and Power

Computers can be generally classified by size and power as follows, though there is considerable overlap:

personal computer: a small, single-user computer based on amicroprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.

workstation: a powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.

minicomputer: a multi-user computer capable of supporting from 10 to hundreds of users simultaneously.

mainframe: a powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.

supercomputer: an extremely fast computer that can perform hundreds of millions of instructions per second.

CSC 134

My name is Mohd Ridzwan Zulnizam Bin Zulkifli. I was born in Seremban, Negeri Sembilan, but grew up in Lumut, Perak.
I am still studying and i love to be a student. I met a lot of friends along my interesting 23 years journey. They help me lot in my study. Some times, the may become a guiders for me in making decision. But, the one i respect and give my trust to is absolutely my beloved parent. They are the one who always along with me facing the need and deed, be with me during happy and sadness and the only persons who have the authority to manage my beautiful life. Thanks to Allah S.W.T for send them to me. Alhamdulillah.
Talking about my study, recently i doing my diploma in applied science in one of the Universiti Teknologi Mara(UiTM) campus. It a good place and convenience to study. Now i am in my forth semester. One of my subject in this interesting semester is Computer and Information Processing (CSC 134).This subject make me know a lot about information technologies and one of the reason why i am interested to write this simple essay. My lecturer also was very kind. She help me lot in my study. I love to be the one who having this chance to explore about the computer and information processing.
Until here we met. Hopefully to meet again. Thank you.