BCA2010 – OPERATING SYSTEM

Dear students get fully solved assignments

Send your semester & Specialization name to our mail id :

  “ help.mbaassignments@gmail.com ”

or

Call us at : 08263069601

(FALL 2014) ASSIGNMENT

PROGRAM	BCA (Revised Fall 2012)
SEMESTER	2
SUBJECT CODE & NAME	BCA2010 – OPERATING SYSTEM
CREDIT	2
BK ID	B1405
MAX.MARKS	60

Note: Answer all questions. Kindly note that answers for 10 marks questions should be approximately of 400 words. Each question is followed by evaluation scheme.

1 Differentiate between Distributed Systems and Real-time Systems.

Answer : A distributed real-time system composes two challenging sets of properties which are imposed by the problem domain or the solution domain (or both.)

Distributed

A distributed system links a number of independent computing entities with local properties by way of a communication mechanism. As a consequence, algorithms and other design components must take into consideration the synchrony and the failure model. A useful summary (not entirely objective) of distributed computing concerns is included in Deutsch's Eight Fallacies of Distributed Computing. (See this useful exposition.) All of these are useful to consider in (real-time) distributed design; each is a departure point for essential design and implementation concerns:

1)      The network is reliable

2)      Latency is zero

3)      Bandwidth is infinite

4)      The network is secure

2 Explain the different process states.

Answer : A process is a program in execution. The execution of a process must progress in a sequential fashion. Definition of process is following.

A process which is Executed by the Process have various States, the State of the Process is also called as the Status of the process, The Status includes whether the Process has Executed or Whether the process is Waiting for Some input and output from the user and whether the Process is Waiting for the CPU to Run the Program after the Completion of the Process.

The various States of the Process are as Followings:-

1) New State : When a user request for a Service from the System , then the System will first initialize the process or the System will call it an initial Process . So Every new Operation which is Requested to the System is known as the New Born Process.

2) Running State : When the Process is Running under the CPU, or When the Program is Executed by the CPU , then this is called as the Running proce

3 Define Deadlock. Explain necessary conditions for deadlock.

Answer : A deadlock is a situation in which two computer programs sharing the same resource are effectively preventing each other from accessing the resource, resulting in both programs ceasing to function. The earliest computer operating systems ran only one program at a time. Eventually some operating systems offered dynamic allocation of resources. Programs could request further allocations of resources after they had begun running. This led to the problem of the deadlock.

 Coffman (1971) identified four (4) conditions that must hold simultaneously for there to be a deadlock.

1. Mutual Exclusion Condition

The resources involved are non-shareable.

Explanation: At least one resource (thread)

4 Differentiate between Sequential access and direct access methods.

Answer : The hypertext and hyperlink exemplify the direct-access paradigm and are a significant improvement over the more traditional, book-based model of sequential access.

(Direct access can also be called random access, because it allows equally easy and fast access to any randomly selected destination. Somewhat like traveling by a Star Trek transporter instead of driving along the freeway and passing the exits one at a time, which is what you get with sequential access.)

In a normal, physical book, the reader is supposed to read pages one by one, in the order in which they are provided by the author. For most

5 Differentiate between Daisy chain bus arbitration and Priority encoded bus arbitration.

Answer : In most mini- and mainframe computer systems, a great deal of input and output occurs between the disk system and the processor. It would be very inefficient to perform these operations directly through the processor; it is much more efficient if such devices, which can transfer data at a very high rate, place the data directly into the memory, or take the data directly from the processor without direct intervention from the processor. I/O performed in this way is usually called direct memory access, or DMA. The controller for a device employing DMA must have the capability of generating address signals for the memory, as well as all of the memory control signals. The processor informs the DMA controller that data is available (or is to be placed into) a block of memory locations starting at a certain address in memory. The controller is also informed of the length of the data block.

6 Differentiate between encryption and decryption. What are the two basic methods for encryption?

Answer : Encryption and decryption are both methods used to ensure the secure passing of messages and other sensitive documents and information.

Encryption basically means to convert the message into code or scrambled form, so that anybody who does not have the 'key' to unscramble the code, cannot view it. This is usually done by using a 'cipher'. A cipher is a type of algorithm used in encryption that uses a certain described method to scramble the data. The cipher can only be 'deciphered' with a 'key'. A key is the actual 'described method' that was used to scramble the data, and hence the key can also unscramble the data.

When the data is unscrambled by the use of a key

Dear students get fully solved assignments

Send your semester & Specialization name to our mail id :

  “ help.mbaassignments@gmail.com ”

or

Call us at : 08263069601