About Hardware

1. HARDWARE
DEVICES
M A D E B Y : - A A K A S H K U M A R
T R I P A T H I
C L A S S : - 9 ( F )

2. COMPUTERS
• Computers are automatic, electronic machines
that
– accept data & instructions from a user (INPUT)
– store the data & instructions (STORAGE)
– manipulate the data according to the instructions
(PROCESSING)
– store &/or output the results to the user (OUTPUT)
• A computer system is composed of hardware and
software
• Hardware components are the physical, tangible
pieces that we can see and touch

3. HARDWARE

4. Input Devices
• Input Devices: devices that input information into
the computer such as a keyboard, mouse,
scanner, and digital camera.

5. Output Devices
• Output: devices that output information from the
computer such as a printer and monitor.

6. Central Processing Unit
– CPU (Central Processing Unit) also called the
Microprocessor or “The Brain” of the
Computer.
– Processor speed: The speed at which a
microprocessor executes instructions. This is
usually measured in megahertz (MHz).

7. Central Processing Unit
– Computer chip: also called the
microprocessor may contain an entire
processing unit.
– Computer chips contain millions of transistors.
They are small pieces of semi-conducting
material (silicon).
– An integrated circuit is embedded in the
silicon. Computers are made of many chips
on a circuit board.

8. Data Storage Devices
– The hard-drive is a mechanical storage device
typically located internally.
• Fast recording and recovery of data
• Large storage capacity
• Magnetic
• Primary storage device for data and programs
• Speed is measured in R.P.M.’s

9. Hardware
• Units of measure
– All done relative to a Byte (8 bits - 1 character)
– KB = Kilobyte - 1 thousand bytes (1024)
– MB = Megabyte - 1 million bytes (1,048,576)
– GB = Gigabyte - 1 billion bytes
– TB = Terabyte - 1 trillion bytes
• To understand how data is represented and stored
on a diskette, see the slides titled Diskettes in the
Additional Material at the end of this lecture

10. Hardware Devices
• Storage
– Two types
• Primary and secondary
• Primary Storage (main memory)
– On board memory (located on the motherboard)
– Very fast, but expensive
– Two types
• RAM – Random Access Memory
• ROM – Read Only Memory

11. Hardware Devices
• RAM - Random Access Memory
– Read/write capability
– Contents lost when computer is turned off
(volatile)
– A program must be in RAM for it to execute
– 128 to 256MB for a typical desktop computer

12. Hardware Devices
• ROM - Read Only Memory
– Read but not write capability
– Permanent (non volatile)
– Stores the preliminary instructions to be executed
when the computer is turned on, for example
• To check RAM
• To check communications with peripheral devices
• Bootstrap loader program

13. Hardware Devices
• Secondary Storage (secondary memory)
– External devices (not on the motherboard); either
inside or outside the computer
– Store programs and data permanently

14. THANK YOU