Hardware Information Created by Nasih 1

Hardware  The physical components of a computer system, including any peripheral equipment such as printers, modems, and mouse devices. 2

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 3

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 4

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 5

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. 6

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 7

Storage  Primary  Cache  Main memory (RAM)  Secondary  Hard disk  Removable (e.g., CD, floppy) 8

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. 9

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. 10

RAM  Main Memory  Volatile ROM  Secondary 11

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 12

Output devices  A piece of hardware that can be used for receiving data from computer. Example:- Printer, plotter, speaker … etc. 13

Computer Measurement units 1- Bit ( B inary dig IT )  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. 14

2. Byte : a sequence of 8 contiguous bits (typically)  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: or  Can also represent a character 2. Word : a sequence of 4 or 8 contiguous bytes (typically); i.e., 32 or 64 contiguous bits 15

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 16

Binary via Decimal 17