Introduction to Computer
Special ThanksS.W.A.Shah
NIST
You will learn about: • Hardware including:• Input devices.• Processor or central processing unit (CPU).• Output devices.• Memory.• Software • Definitions of basic computer terms
Computer Hardware: • A computer consists of both hardware
(physical parts of the computer) and software working together to help you accomplish tasks.
• Hardware consists of: • Input devices• Processor or central processin
g unit (CPU)• Memory
Input devices: • Input devices are machines that
communicate with the computer.• Examples of input devices are the
keyboard and the mouse. • Input devices are controlled by the
user.
• For example, typing on the keyboard or clicking on a mouse button.
Processor or CPU: • Processor or CPU:• CPU is short for
Central Processing Unit.
• The CPU is a microchip inside the computer.
• The box that the processor resides in is commonly referred to as the CPU.
Processor or CPU:• The translation or processing of your
input takes place in the CPU. • Processing is the thinking that the
computer does - the calculations, comparisons, and decisions.
• The box contains the microchip, the floppy disk drive, the CD-ROM drive, and memory.
Output devices: Output devices are machines that display information from the computer (CPU).
• Output devices are controlled by the computer. After the processor translates the information from the input devices, the output devices deliver the information to the user.
Memory: • The cycle (input - processing - output)
would not be possible without a holding place for the instructions and data that the processor (CPU) can easily reach.
• This holding place is known as memory. • There are three basic types of memory:
types of memory • RAM - Random Access
Memory• ROM - Read Only Memory• Storage Devices
RAM:• The primary memory that holds data and
instructions while the computer is in use.• Can be thought of as the memory the
computer uses to obey instructions. • Can be written to and read from.• Important to remember that if you do not save
the information in RAM to a storage device (such as a floppy disk or hard drive) before turning off the computer the information will be lost
ROM:• ROM is more straight forward.• ROM is built in memory that
permanently stores instructions and data.
• The instructions and data in ROM are created when it is manufactured and it cannot be changed.
ROM (BIOS CHIP)
Storage Devices: • A storage device is a place to
store data. Although there are several types of disks, for the purposes of this tutorial, only the following types will be discussed:
Hard Drive:• A permanent data storage device built
into PCs that permits you to save and retrieve information.
• Also, stores the computer's operating system and other software.
• The size of a hard drive is usually expressed in terms of megabytes and gigabytes.
Floppy Disk:Floppy disks allow information to be transported easily from one computer to another.Floppy disks have limited storage capacity, generally 1.44 MB.Saving and retrieving information from a floppy disk is slower than on a hard drive.They are more susceptible to physical damage and viruses than the hard drive.
CD ROM:• CD ROMs are read only storage
medium.• Typically, a CD ROM holds up to
650 MB of information.• While information retrieval is
faster than from a floppy disk, it is still not as fast as from the hard drive.
CD-RW:• A CD-RW allows you to read, write,
erase and write again.• Writing takes place in a single pass of
the focused laser beam.• This is sometimes referred to as direct
overwriting and can be repeated several thousand times per disc.
Computer Software: • Software is:• What makes the computer work. • Software consists of an organized list of
instructions that causes the computer to behave in a predetermined manner.
• For work, for play, for kids, and for adults.
• A computer game you play or a word processing program.
• Often divided into two categories: system software and application software.
• System software includes the operating system, compilers and utilities that enable the computer to function.
• Application software includes programs that perform specific tasks (e.g., games, word processors, spreadsheets, and databases).
• Figuratively speaking, application software sits on top of system software because the computer is unable to run without the operating system and system utilities.
End of the Lecture?