INTRODUCTION TO OPERATING SYSTEMS

TDC 311

What is an Operating System?

It is a provider of servicesWhat kind of services?

Creation, support, and termination of threads Operation of all I/O functions Support of the file system Detecting process and system errors and making

corrections Allocating system resources such as memory, the

processor, and I/O devices Support of all accounting functions Support security operations Support of network operations

How Does an OS Offer These Services?

You click on an iconYou type a command line prompt

ping 138.54.101.1

You submit a batch job with appropriate JCL// JOB ID=1234,T=3s

//EXEC PGM=QSAMCOPY//DD SYSINPUT=RER123.56//DD SYSOUT=DISK3

How Does an OS Offer These Services?

From within a higher level language application, you call on an OS function

seekp( loc_address, ios::beg);write( &Taken,1);no_records++;$create_proc(&Param1, &Param2, 0, 0);

How Does an OS Offer These Services?

From within a lower level language application, you call a macro or subroutine

NEXT C 6,FULWDBE EQ$CREPROC XVAL,YVAL,0,0

A currently existing OS function calls on another OS function

Types of Operating Systems

Mainframe (IBM VM/ESA for IBM 390 systems, Unix, Linux)

Personal computers (Windows, MAC OS, Unix, Linux)

Local area networks (Windows, Unix, Linux)Distributed systems (Amoeba)

Real-time Embedded

Palm-based systems PDAs Cellphones

Actual Operating Systems

Think there is only a couple operating systems out there?

Think againLook at http://tunes.org/Review/OSes.html