Transcript Introduction to Database Systems

COMP1070
Lecture #3
Operating Systems
 Describe briefly operating systems service
 To describe character and graphical user interfaces
 To describe different types of operating systems
 Little UNIX( what UNIX is )
 Go to lab 106

COMP1070/2002/lec3/H.Melikian
Introduction
The primary propose of an operating system is to facilitate
easy, efficient, fair, orderly and secure use of commuter
system resources.
It allows the user of computer system to use
application software – email, Web, word processors
language libraries, system calls
Hardware resources which include, keyboard, display,
memory, drives and CPU .
AUI – application user interface
API- application programmers interface
COMP1070/2002/lec3/H.Melikian
Figure 1 A layered view of a contemporary computer system
COMP1070/2002/lec3/H.Melikian
What is an Operating system
AUI is glued to operating systems kernel via the language
libraries and system call interface.
System calls- a set of functions that can be used by
applications and library routines to start execution of the
kernel code for particular service, reading or writing a file..
The kernel is the part of an operating system where the
real work is done
Operating system can be viewed as resource manager
COMP1070/2002/lec3/H.Melikian
Operating system Services
The major operating system services therefore provide
mechanisms for secure and efficient

Execution of a program

I/O operations performed by program

Communication between processes

Error detection and reporting

Manipulation of all kind of files
COMP1070/2002/lec3/H.Melikian
Character and Graphical User Interfaces
If you use keyboard to issue commands to the operating
system - CUI
If the primary device for issuing commands to the operating
system is a point and click devise (mouse) then we say that the
operating system has – GUI
Some operating system have both and you can use either.
Operating systems like UNIX and DOS they have –CUI
MacOS, OS/2, Microsoft Windows - GUI
COMP1070/2002/lec3/H.Melikian
Types of Operating Systems
Operating systems can be categorized by number of users
who can use a system at the same time and number of
processes that operating system can run simultaneously.
 Single user, single process system
( PC, mMacOS, Dos, Windows3.1)

Single user, multiprocesses system
(PC, OS/2, Windows NT workstations)

Multiuser, multiprocess system
UNIX, LINUX, Windows NT Server
COMP1070/2002/lec3/H.Melikian
HW #3
Go down Lab 106 RS Building.
Comp 1070 Lab 1
1.Introduction to computing environment in Math & CS department at NCCU.
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Computer Labs: Room 106, Room 209
Computers: PCs running windows 2000 with Ethernet connection
(Room 106), SiliconGraphics machines running Unix (Room 209)
Servers: picard (NT/2000), laplace (LINUX)
Useful software: C/C++ Java compilers, Textpad, Putty.exe, etc
2.Logging into course website:
a.
Open a web browser such as IE or Netscape
b. Enter the following address: http://onlinecourse.nccu.edu
c.
Click on login button
d. Enter user name and password. (
e.
Click intro to computing under My Courses
f.
When you want to get out, click logout button on top.
COMP1070/2002/lec3/H.Melikian
3.Logging into UNIX machine (Laplace)
a. Open putty.exe ( click putty.exe icon on desctop)
b. Enter IP address: 152.9.45.20 and check SSH button under Protocol.
c.
Click Open.
d. Another window pops up and it says: login as:
e. Enter your user name. Your user name is composed of your last name
and first letter of your first name. E.g., the user name of John Doe is
doej. (username must be in all lowercase letters !!)
f.
Initial password is comp1000. You can of course change it later.
g.
Try some simple UNIX commands such as: pwd, cd, and ls.
4.Logging out of UNIX machine
a.
It is very important that you log out at the end of each session.
b. Enter logout at a prompt.
Do not forget your password
If you need a help Do Not Hesitate Ask for It
Welcome back to Laplace very soon
COMP1070/2002/lec3/H.Melikian