Name of the College : Noorul Islam College of Engineering
University : Anna University
Degree : B.E
Department : Computer Science and Engineering
Subject Code/Name : CS 1203 – System Software
Document Type : Question Bank
Website : niceindia.com
Download :https://www.pdfquestion.in/uploads/ni…m_Software.pdf
NICE System Software Question Bank
UNIT I
Unit I – Introduction :
1. Define system software :
It consists of variety of programs that supports the operation of the computer. This software makes it possible for the user to focus on the other problems to be solved with out needing to know how the machine works internally.
Related : Noorul Islam College of Engineering EC1403 Microwave Engineering B.E Question Bank : www.pdfquestion.in/2970.html
Eg : operating system, assembler, loader.
2. Give some applications of operating system :
** to make the computer easier to use
** to manage the resources in computer
** process management
** data and memory management
** to provide security to the user.
Operating system acts as an interface between the user and the system
Eg :windows,linux,unix,dos
3. Define compiler and interpreter :
Compiler is a set of program which converts the whole high level language program to machine language program.
Interpreter is a set of programs which converts high level language program to machine language program line by line.
4. Define loader :
Loader is a set of program that loads the machine language translated by the translator into the main memory and makes it ready for execution.
5. What is the need of MAR register? :
MAR (memory address register) is used to store the address of the memory from which the data is to be read or to which the data is to be written.
7. Give any two differences between base relative addressing and program counter relative addressing used in SIC/XE.
8. Define indirect addressing :
In the case of immediate addressing the operand field gives the memory location. The word from the given address is fetched and it gives the address of the operand.
Eg :ADD R5, [600]
Here the second operand is given in indirect addressing mode. First the word in memory location 600 is fetched and which will give the address of the operand.
9. Define immediate addressing :
In this addressing mode the operand value is given directly. There is no need to refer memory. The immediate addressing is indicated by the prefix ‘#’.
Eg : ADD #5
In this instruction one operand is in accumulator and the second operand is an immediate value the value 5 is directly added with the accumulator content and the result is stored in accumulator.
13. What is the name of A and L register in SIC machine and also specify its use :
A-accumulator :
Used for arithmetic operation. i.e., in the case of arithmetic operations one operand is in the accumulator, and other operand may be an immediate value, register operand or memory content. The operation given in the instruction is performed and the result is stored in the accumulator register.
L-linkage register :
It is used to store the return address in the case of jump to subroutine (JSUB) instructions.
UNIT II
ASSEMBLERS
1. Define the basic functions of assembler.
* Translating mnemonic operation codes to their machine language equivalents.
* Assigning machine addresses to symbolic labels used by the programmer.
2. What is meant by assembler directives? Give example.
These are the statements that are not translated into machine instructions, but they provide instructions to assembler itself. example START,END,BYTE,WORD,RESW and RESB.
3. What are forward references?
It is a reference to a label that is defined later in a program. Consider the statement
The first instruction contains a forward reference RETADR. If we attempt to translate the program line by line, we will unable to process the statement in line10 because we do not know the address that will be assigned to RETADR .The address is assigned later(in line 80) in the program.
4. What are the three different records used in object program?
The header record, text record and the end record are the three different records used in object program.
5. What is the need of SYMTAB (symbol table) in assembler?
The symbol table includes the name and value for each symbol in the source program, together with flags to indicate error conditions. Some times it may contain details about the data area. SYMTAB is usually organized as a hash table for efficiency of insertion and retrieval.
UNIT III
LOADERS AND LINKERS
1. What are the basic functions of loaders?
• Loading – brings the object program into memory for execution
• Relocation – modifies the object program so that it can be loaded at an address different from the location originally specified
• Linking – combines two or more separate object programs and also supplies the information needed to reference them.
2. Define absolute loader.
The loader, which is used only for loading, is known as absolute loader.
e.g. Bootstrap loader
3. What is meant by bootstrap loader?
This is a special type of absolute loader which loads the first program to be run by the computer. (usually an operating system)
4. What are relative (relocative) loaders?
Loaders that allow for program relocation are called relocating (relocative) loaders.
5. What is the use of modification record?
Modification record is used for program relocation. Each modification record specifies the starting address and the length of the field whose value is to be altered and also describes the modification to be performed.