Computer Basics

© Copyright 2003 Janna B. Gallaher

The Personal ComputerThe Personal Computer

t The personal computer was made possible by the invention of solid state electronics and specifically the integrated circuit.t The first microprocessors were made in the late 1960’s and were

very simple in structure

PC ArchitecturePC Architecture

Cache

Memory

Video Ram

Video Processor

Bridge LAN Bridge

BIOS

Local Bus 64-bit data, 32-bit address, 133 mhz

Hard Disk

EISA Bus PCI BusEthernet

Monitor

DRAM

64mB – 1GB

Floppy Disk

CD ROM

Keyboard

Mouse

Bridge

USB

Motherboard Power On Reset

Sound

CPU

PC MotherboardPC MotherboardtGigybyte GA-71XE motherboard

MicroprocessorISA Expansion Slots

PCI Expansion Slots

BIOS

AGP Video Connector

Floppy Disk Connector

Battery

RAM Memory Slots

Parallel and Serial Ports

Keyboard and Mouse connectors

Hard Disk Drive Connectors

PC Motherboard Block DiagramPC Motherboard Block DiagramtGigabyte GA-72XE motherboard block diagram (from the owner’s

manual)

The MicroprocessorThe Microprocessort Block diagram of an Intel 8086 microprocessor

Interrupt Control

Accumulator

Temp. Register

Flag Flip-flops

Arithmetic Logic Unit (ALU)

Instruction Register

Instruction Decoder and

Machine Cycle Encoding

Timing and Control

Serial I/O Control

B

Reg

C

Reg

D

Reg

E

Reg

H

Reg

L

Reg

Stack Pointer

Prog. Counter

Inc/Dec AddressAddress Buffer

Address

Data

Buffer

Register Array

8-bit Internal Data Bus

The Microprocessor (continued)The Microprocessor (continued)t Block diagram of the Intel Itanium processor which is one of the

newer microprocessors available

Diagram courtesy Intel Corp

SoftwareSoftwaret There are 3 levels of software required to do something on a PC

t The BIOSt The Operating Systemt Applications

Operating System

Manages computer operation

BIOSUsed during boot process

Application: Word Processor

Application: Photo Editor

Application: Database

Application: HTML Editor

Programs Stored on Disk

RAM

Memory

SoftwareSoftwaret BIOS

t Lowest level program on the PCt BIOS is an acronym for: Basic Input/Output Systemt It is a program that is stored in Read-Only-Memory on the motherboardt It is a program that is unique to each motherboard model and provides disk

drive configuration information for the operating system along with the system time, security access, and other low-level settings.

t The BIOS is executed during the boot process

BIOS Chip

The Operating System SoftwareThe Operating System SoftwaretOperating System

t The operating system is the software that has the job of managing all of the tasks that a computer is asked to do

t It performs file management and it writes to and reads from the diskt It loads and executes application programstManages how to use all of the peripheral devicestReceives commands from the keyboard and outputs data to the monitort Two popular operating systems for the PC are Windows and Linux

although there are others

Application ProgramsApplication Programst Applications are programs that you run to

perform tasks on the computertMicrosoft Word, PowerPoint, Access, Visual

Studio, MathCad, AutoCad, Photoshop, and Oracle are just a few of thousands of programst These programs must be written using a

programming language that will convert an idea into instructions that a computer can execute

Programming LanguagesProgramming Languagest Programming languages allow us to

convert ideas into computer codet The computer can only understand

sequences of 1’s and 0’s and humans are used to conversing in English or some other language

t A programming language provides the means of converting English sentences into machine code

t There are many programming languages and each one has its advantages and disadvantages

t One good general purpose programming language is C

Writing ProgramsWriting Programs

tWriting programs involves knowing several things:t The application – what it is that you want to do on the computert The operating system – how does the program interface with the computert The language syntax – what it takes to write programst A program development environment – a compiler and debugger or other

program development toolstOther tools such as mathematics, fuzzy logic, artificial intelligence

algorithms, signal processing techniques, etc.

t Engineering the solution must be done first before any code is written