CS116Introduction to Computer Science I

Lecture 1 (Extra) Introduction to Computer Systems

Instructor: Li Ma

Department of Computer ScienceTexas Southern University, Houston

August, 2011

by Li Ma 2

Computer SystemsComputer is a programmable electronic deviceComputer has 4 basic computing functions

InputProcessingOutputStorage

Types of ComputersSupercomputer: large and powerfulMainframe computer: multitaskingMinicomputer: for medium-sized businessMicrocomputer: desktop computer, notebook

computer, tablet computer, Personal Digital Assistant (PDA)

by Li Ma 3

Hardware of Computer SystemsMotherboard: the primary printed circuit board

in a PCAll the other circuit boards in the computer are

connected to motherboardCPURAM chipsExpansion cardsProcessor and coprocessor socketsMemory socketsSerial and parallel portsPeripheral controllersSystem bus

by Li Ma 4

Hardware of Computer Systems (cont’)The central processing unit (CPU)

Fetch instructions, follow the instructions, and produce some results Control unit Arithmetic and logic unit (ALU)

Main memory (Random-access memory, RAM) It holds the sequences of instructions in the programs

that are running and the data those programs are using It is a volatile type of memory, used only for temporary

storageData will be lost when power is off

by Li Ma 5

Hardware of Computer Systems (cont’)Secondary storage devices

Type of memory that can hold data for long periods of time Disk drives: hard disk, floppy disk, Zip disk, etc. Optical devices: compact disk (CD) Flash drives: or thumb drives, directly plug to USB port

Input deviceskeyboard, mouse, scanner, microphone, and digital

cameraOutput devices

printer, monitor, and speakersecondary storage devices

by Li Ma 6

Hardware of Computer Systems (cont’)Others

Modem: a communication deviceVideo Card: an expansion card, responsible for

transforming graphics and text signals onto the monitor

Power Supply: responsible for converting the standard power into an energy form that your computer can use

System Buses: channels over which information flows between two or more devices

by Li Ma 7

Software of Computer SystemsSoftware refers to the programs that run on a

computer, there are two categories:Operating System (OS): interface between hardware and

software DOS: Disk Operating System Windows Unix Linux: portable Unix Macintosh

Application software: developed by users, for some specific purpose

by Li Ma 8

MS-DOSA set of programs that allows users to interact

with a computerOnce you turn on the computer, it will be

loadedIt has a command-line interfaceFile and Directory Structure

Tree-likeNodes: directories and files

Windows 95 folded DOS into GUI (Graphical User Interface)Friendly interfaceEasier to operate

by Li Ma 9

WindowsWindows 95

First truly combined the operating system and GUI for the Intel-based computers

Windows 98Logical extension of Windows 95More efficient Integrates World Wide Web (WWW) capabilities into

the operating systemNewer version of Windows

Windows 2000, Windows XP, Windows Vista, …

by Li Ma 10

Windows (cont’)Icons and Graphical User Interfaces (GUI)

A software program that allows you to communicate with your computer by using a pointing device like mouse.

Application Suites in WindowsMicrosoft visual studioMicrosoft office Internet Explorer, Etc.

by Li Ma 11

Windows XPWindows refers to the operating system that

runs the PC or PC-compatible computers It is loaded once you turn on the computer

Desktop: the basic screen on which Windows and application runTaskbar, Shortcut icons, Start button, Quick-Launch

toolbar, System tray, Mouse pointerA window is a rectangle area for some certain

application It can be opened and closed It can also be resized, moved, and reduced to a

button (to the task bar)

by Li Ma 12

Windows XP (cont’)File and Directory Structure

Like file cabinets: files and foldersMy Computer: view your disks, folders and files

Create a new folderCopy, move, rename, and delete filesFind files and foldersCompress (or zip) files

by Li Ma 13

Microsoft OfficeA set of powerful applications (or a suite) that

has been designed to work togetherShare data to combine text, chart & database

information in one documentWord: word processingExcel: electronic spreadsheet manipulationPowerPoint: making presentation materialsAccess: manipulating databasesFrontPage: developing web pagesOutlook: tracking the schedule, checking email

by Li Ma 14

Microsoft Office (cont’)Web aware

All applications can be used to access or generate HTML document

Starting an office applicationDouble-click the icon on the desktop (shortcut) Invoke the Start, Programs command sequenceOpen an associated file

Office AssistantVery useful to new user