System Software - Dec 2011

Computer Science Engg. (Semester 5)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What is the system software? Compare system software with application software and given couple of examples.(4 marks) 1 (b) Explain the instruction formats and addressing modes of SIC/XE machine architecture.(10 marks) 1 (c) Sippose the ALPHA is an array of 100 words. Write a sequence of instructions for SIC/XE to set all 100 elements of the array to ZERO. Use immediate addressing and registar to register addressing to make the process as efficient as possible.(6 marks) 2 (a) What are the fundamental funtions that any assembler must perform? With a sutaible example, explain any six assembler directives.(10 marks) 2 (b) Write an algorithm for PASS-1 of two pass assembler and explain with an example.(10 marks) 3 (a) What is literal? What are differences between literal and immediate operand.(4 marks) 3 (b) What are program blocks? With a suitable example, explain how program blocks are handled by an assembler.(6 marks) 3 (c) Give the format of the following records necessary to obtain objects code:
(i) Define record (ii) Refer record (iii) Modification records (revised)(10 marks) 4 (a) What is loader? What are the basic functions the loader has to perform?(4 marks) 4 (b) What is relocation? Explain the methods for specifying relocation as a per of object program.(8 marks) 4 (c) Explain the working of linkage editor and linkage loader.(8 marks) 5 (a) Explain the different task to be accopmlished b a text editor for an interactive user computer dialogue.(1 marks) 5 (b) With a neat diagram, explain the working of a typical editor structure.(10 marks) 6 (a) What is MACRO? Briefly discuss various data structures required for a design of MACRO PROCESSOR.(8 marks) 6 (b) With regrad to machine independent macroprocessor feature, explain the followings:
(i) Concatenation of MACRO parameters
(ii) Generation of unique labels
(iii) Conditional MACRO expansion
(iv) Keyword macro parameters(12 marks) 7 (a) Discuss the character that used in the meta language as part of standard ASCII character set used in UNIX operating system.(8 marks) 7 (b) What is LEX? Explain the LEX specification format.(6 marks) 7 (c) Write a LEX program to indentify the decimal numbers.(6 marks) 8 (a) What is YACC? Explain the different sections used in writing the YACC specification.(10 marks) 8 (b) Write a YACC program to function as a calculator which performs addition, subtraction, multiplication, division and unary operations.(10 marks)