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Understanding Computer Hardware - 2

Sohaib A Khan

CS101: Lec 4.1

Figure Acknowledgements: “How Computers Work” 6th Ed by Ron White (Illustrated by Timothy Edward Downs) © Que Corp 2002

Parts of a Personal Computer (PC)

• Hardware

• The physical parts of a computer

• Any part of the computer that you can touch

• Software

• Set of instructions to tell the computer what it should do

• Computer Programs are pieces of

software

• Data

• Pieces of information

• Computer process data

• Users

• People operating the computer

• Most important part

• Tell the computer what to do

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Computer Ports

• Mouse

• Keyboard

• USB

• Serial

• Parallel

• Modem

• Network

• Microphone

• Speakers

• VGA

• S-Video

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The Motherboard

• PCB (Printed Circuit Board) made of Fiberglass sheet with electrical pathways, called traces, etched into it• System Clock

• Microprocessor• Read-Only Memory (ROM)

• Random Access Memory (RAM)

• Battery

• Power Supply

• Ports• Expansion Slots

• Buses• Address Bus

• Data Bus

Microprocessor

• Sometimes also called CPU

• Control Unit

• Arithmetic-Logic Unit

• Cache Memory

• Fast memory built into the processor

• Based on the idea that statistically,

instructions and data are reused

often

• CISC vs. RISC Processors

• CISC: Complex Instruction Set

Computing

• RISC: Reduced Instruction Set

Computing. RISC computers

understand smaller number of

instructions, but are often faster

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Memory

• Volatile vs Non Volatile Memory

• Random Access vs Sequential Access

• Some Common Types

• Read-Only Memory (ROM)

• Random Access Memory (RAM)

•CMOS Memory

•Cache Memory

• Flash Memory

Power On Self Test (POST)

1. Memory is cleared. Program

Counter is reset

2. BIOS (Basic Input/Output System)

stored in ROM is invoked. Carries

out a series of self checks

3. Signals sent over system bus to

check status of all components

4. Memory Read/Write Test

5. Essential Peripherals are checked

(Keyboard, Harddisk etc).

6. Results of POST are compared

against stored configuration in

CMOS chip…

7. If everything is OK, control is

handed over to Operating System

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Harddisk

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Input/Output Devices

• Input Devices

• Output Devices

• Devices which are both Input and Output

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Continuation of Hardware Lecture…

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Reading

• Ch 1B: Looking Inside a Computer System

• Ch 2A: Using Keyboard and Mouse

• Ch 2B: Inputting Data in Other Ways

• Ch 3A: Video and Sound

• Ch 4A: Transforming Data Into Information

• Ch 4B: Modern CPUs

• Ch 5A: Types of Storage Devices