Instructor: Li Ma
Department of Computer Science
Texas Southern University, Houston
August, 2011
Computer Systems
 Computer is a programmable electronic device
 Computer has 4 basic computing functions
 Input
 Processing
 Output
 Storage
 Types of Computers
 Supercomputer: large and powerful
 Mainframe computer: multitasking
 Minicomputer: for medium-sized business
 Microcomputer: desktop computer, notebook computer, tablet
computer, Personal Digital Assistant (PDA)
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Hardware of Computer Systems
 Motherboard: the primary printed circuit board in a PC
 All the other circuit boards in the computer are connected
to motherboard
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CPU
RAM chips
Expansion cards
Processor and coprocessor sockets
Memory sockets
Serial and parallel ports
Peripheral controllers
System bus
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Hardware of Computer Systems (cont’)
 The central processing unit (CPU)
 Fetch instructions, follow the instructions, and produce some
results
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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 storage
 Data will be lost when power is off
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Hardware of Computer Systems (cont’)
 Secondary storage devices
 Type of memory that can hold data for long periods of time
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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 devices
 keyboard, mouse, scanner, microphone, and digital camera
 Output devices
 printer, monitor, and speaker
 secondary storage devices
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Hardware of Computer Systems (cont’)
 Others
 Modem: a communication device
 Video 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
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Software of Computer Systems
 Software refers to the programs that run on a computer,
there are two categories:
 Operating System (OS): interface between hardware and software
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DOS: Disk Operating System
Windows
Unix
Linux: portable Unix
Macintosh
 Application software: developed by users, for some specific purpose
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MS-DOS
 A set of programs that allows users to interact with a
computer
 Once you turn on the computer, it will be loaded
 It has a command-line interface
 File and Directory Structure
 Tree-like
 Nodes: directories and files
 Windows 95 folded DOS into GUI (Graphical User
Interface)
 Friendly interface
 Easier to operate
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Windows
 Windows 95
 First truly combined the operating system and GUI for the
Intel-based computers
 Windows 98
 Logical extension of Windows 95
 More efficient
 Integrates World Wide Web (WWW) capabilities into the
operating system
 Newer version of Windows
 Windows 2000, Windows XP, Windows Vista, …
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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 Windows
 Microsoft visual studio
 Microsoft office
 Internet Explorer, Etc.
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Windows XP
 Windows 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 run
 Taskbar, Shortcut icons, Start button, Quick-Launch toolbar,
System tray, Mouse pointer
 A 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)
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Windows XP (cont’)
 File and Directory Structure
 Like file cabinets: files and folders
 My Computer: view your disks, folders and files
 Create a new folder
 Copy, move, rename, and delete files
 Find files and folders
 Compress (or zip) files
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Microsoft Office
 A set of powerful applications (or a suite) that has been
designed to work together
 Share data to combine text, chart & database
information in one document
 Word: word processing
 Excel: electronic spreadsheet manipulation
 PowerPoint: making presentation materials
 Access: manipulating databases
 FrontPage: developing web pages
 Outlook: tracking the schedule, checking email
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Microsoft Office (cont’)
 Web aware
 All applications can be used to access or generate HTML document
 Starting an office application
 Double-click the icon on the desktop (shortcut)
 Invoke the Start, Programs command sequence
 Open an associated file
 Office Assistant
 Very useful to new user
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