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Hardware
Information
Created by Nasih
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Hardware

The physical components of a
computer system, including any
peripheral equipment such as printers,
modems, and mouse devices.
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Categories of Computer
Hardware
 Central
Processing Unit (CPU)
 Storage


Primary: Cache, RAM
Secondary: Hard disk, removable (e.g., CD)
 I/O


Input Devices
Output Devices
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Central Processing Unit (CPU)
 The
Central Processing Unit (CPU), also called the
processor, is the “brain” of the computer.
 Example:



Intel Pentium 4/AMD Athlon (Windows PCs)
Intel Itanium2 (servers)
Qualcomm MSM (cell phones)
The CPU consists of three main parts:



Control Unit
Arithmetic/Logic Unit
Registers
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CPU: Control Unit
 Control
Unit : Control all process inside CPU
 memory operations: for example,


load data from main memory (RAM) into the
registers;
store data from the registers into main memory;
 arithmetic/logical
operations: control
arithmetic and logical decision
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CPU: Arithmetic/Logic Unit
The Arithmetic/Logic Unit (ALU) performs
arithmetic and logical operations.
 Arithmetic operations: e.g., add, subtract,
multiply, divide, square root, cosine, etc.
 Logical operations: e.g., compare two numbers
to see which is greater, check whether a
true/false statement is true, etc.
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CPU: Registers
 Registers
A high-speed memory within a
microprocessor or other electronic device,
used to hold data for a particular purpose.


registers hold the operands being used by the
current arithmetic or logical operation, or the
result of the arithmetic or logical operation that
was just performed.
For example, if the CPU is adding two numbers,
then the addend is in some register, the
augends is in another register, and after the
addition is performed, the sum shows up in yet
another register
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Storage

Primary



Cache
Main memory (RAM)
Secondary


Hard disk
Removable (e.g., CD, floppy)
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Primary Storage
 Primary
Storage the main general-purpose
storage region to which the microprocessor
has direct access, or data and instructions
reside in it when they’re being used by a
program that is currently running.
 Primary Storage is volatile: The data disappear
when the power is turned off.
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Secondary Storage
 The
data and instructions reside that are
going to be used in the future
 This type is not Nonvolatile: data don’t
disappear when power is turned off.
 Therefore much:

Cheaper
Slower
 Most
of them are portable: they can be
easily removed from your computer and
taken to someone else’s.
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RAM
 Main
Memory
 Volatile
ROM
 Secondary
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Input devices
A

peripheral device whose purpose is to
allow the user to provide input to a
computer system.
Example:
Keyboard, mouse, scanner, joystick,
TrackPoint, .. etc
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Output devices
A
piece of hardware that can be used for
receiving data from computer.

Example:
Printer, plotter, speaker … etc.
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Computer Measurement units
1- Bit (Binary digIT)
 Has 2 possible values that we can think of in
several ways:




Low or High: Voltage into transistor
Off or On: Conceptual description of transistor
state
False or True: Boolean value for symbolic logic
0 or 1: Integer value
 Bits
aren’t individually addressable: the CPU
can’t load from or store into an individual bit of
memory.
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2.
Byte: a sequence of 8 contiguous bits
(typically)



2.
On most platforms (kinds of computers), it’s the
smallest addressable piece of memory: typically,
the CPU can load from or store into an individual
byte.
Possible integer values: 0..255 or -128..127
Can also represent a character
Word: a sequence of 4 or 8 contiguous bytes
(typically); i.e., 32 or 64 contiguous bits
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Binary
The binary number system has 2 as its
base, so values are expressed as combinations
of two digits, 0 and 1. These two digits can
represent the logical values true and false as
well as numerals, and they can be represented
in an electronic device by the two states on and
off, recognized as two voltage levels. Therefore,
the binary number system is at the heart of
digital computing
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Binary via Decimal