COMPUTER

ORGANIZATION

COMPUTER

• COMPUTING MACHINE USER

HARDWARE SOFTWARE

SOFTWARE

APPLICATION SOFTWARE

SYSTEM SOFTWARE

OPERATING SYSTEM

OPERATING SYSTEM

• USER-HARDWARE INTERACTION

• NEEDED TO MAKE USE CONVENIENT AND EFFICIENT

• PREVENTS USER PROGRAMS FROM INTERFERING WITH THE PROPER OPERATION OF THE SYSTEM

WHAT IF NO

O/S ?

O/S IN SIMPLE WORDS

I/OOPERATIONS

FILESYSTEM

ERRORDETECTION

RESOURCEALLOCATION

PROGRAMEXECUTION

O/S

COMING TO TECHNICAL VIEW POINT

• Processor management.

• Memory management.

• Device management.

• Application Interface

• User Interface.

KERNEL

Layered structure of

an O/S

A SIMPLE DIAGRAM WILL MAKE IT MORE CLEAR

? What does it do?

OPERATING SYSTEMOPERATING SYSTEM

AA MMOOEEBBAA

SHORT INTRO.

• Amoeba is the fastest growing multi-kernel distributed operating system

• Developed by Andrew Tanenbaum

• First prototype was released in 1983

• The last official update by original developers was in 1996

• Others have developed their own versions

– Fireball Amoeba by Fireball Software Distribution

GOALS OF AMOEBA

DistributionConnecting together many machines.

ParallelismAllowing individual jobs to use multiple CPUs

easily.

TransparencyHaving the collection of computer act like a single system.

PerformanceAchieving all of the above in an efficient manner.

KEY CONCEPTSMicro-kernel

– A simple micro-kernel is the basis for Amoeba

– Each machine in AMOEBA system runs a small identical software programe called a micro-kernel

– Communication b/w client processes & server process

– It handles the memory management, I/O, communication, object primitive, and basic processes

KEY CONCEPTS

• Remote Procedure Calls (RPC)– Used for communication between client and server

• FLIP– Fast Local Internet Protocol

– Developed by Andrew Tanenbaum.

– Designed to optimize the speed of RPCs

KEY CONCEPTS

• Security– 128 bit value known as CAPABILITY.– Used to verify that the user has permission to access

the object.– Capabilities are encrypted

• Directory Server– Handles naming of files– Knows the physical location of each file– Most files can be sent in a single RPC

ARCHITECTURE

• 4 main partS to Amoeba’s Architecture

– Workstations– Processor Pool– Servers– WAN Gateway

BECOMING FAMILIAR WITH

AMOEBA

LOG IN WINDOW

DESKTOP

SOME OTHER APPS.

ADVANTAGES OF AMOEBA

• Can use older/slower CPUs to create powerful system, need not to be of the same architecture (can mix SPARC, Motorola PowerPC, Intel, Pentium, etc.) so your old systems won’t be useless now !

• Micro-Kernel allows for other file systems to be created

• Initially Unix emulation was added by developers to make it compatible with commonly used systems of that time so they have many common commands

ADVANTAGES OF AMOEBA

• Developed from scratch so has the potential to

add compatibility with devices.

• System can be modified easily by a programmer according to requirements.

• It efficiently makes the connected system work with maximum potential

• Process is never swapped out.

Disadvantages

• Can only hold programs as large as its physical memory

• It has not had an official update in over 10 years

• Designed to run on machines with large amounts of RAM and huge local disks

• Process occupies contiguous segments in memory which may give rise to fragmentation

THANKYO

U