OPERATING SYSTEMS T S Pradeep Kumar VITCC http://www.pradeepkumar.org Lecture 1
OVERVIEW What is an Operating System History of Operating system Modern OS Functionality Recent Developments in OS
WHAT IS AN OPERATING SYSTEM Interacts USER Hardware
SERVICES Tasks CPU File System Scheduling OS services Networking Memory
COORDINATION Coordinates multiple applications and processes in a fair manner
GOAL The goal in OS development is to make the machine convenient to use (a software engineering problem) and efficient (a system engineering problem)
ILLUSIONAL FEELING TO AN USER PROVIDES A SERVICE EVERYONE NEEDSFINALLY….
ALWAYS THERE WHEN YOU NEED, NEVER ALLOCATES RESOURCES EFFECTIVELYBREAKS AND PROVIDES SAFETY AND SECURITYFINALLY….
A complexSystem butkeep it assimple aspossible sothat It willworkFINALLY….
HISTORY Phase 0 – Hardware is very expensive, no OS exists One User console Uses Card Deck to load programs
HISTORY Phase 1 – Hardware is expensive, humans are cheap Simple batch processing: load program, run, print results, dump, repeat Overlapped CPU and IO Operations Multiprogrammed Batch Systems Phase 2 – Hardware is less expensive than before, still humans are expensive Interactive timesharing Unix
HISTORY Phase 3 – Hardware is very cheap, humans are cheap Personal Computing
RECENT DEVELOPMENTS Parallel Operating Systems Shared memory and clock, more tightly coupled systems Distributed OS No shared memory or clock, less no of loosely coupled systems Real Time OS (RTOS) Meeting deadline constraints
RECENT DEVELOPMENTS Mobile OS Symbian, Meego, Android, iOS….. Surface OS Click this to see a video