System Software - Jun 2015
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) Give any two differences between SIC and SIC/XE machine architecture.(4 marks) 1 (b) Explain in detail the architecture of a SIC/XE machine.(10 marks) 1 (c) Write a subroutine in SIC/XE to read a 100-byte record from a device 'F5' into BUFFER use immediate and register-to-register instructions.(6 marks) 2 (a) What is a forward reference? How to solve this forward reference in assembler?(4 marks) 2 (b) What are the 3 different records used in object program and write their formats?(6 marks) 2 (c) Generate the objects code for the instruction shown below:
|1) 0006 CLOOP||+JSUP||RDREC|
Note : JSUB=8, J=3C, LDA=00, LDT=74, RDREC=1036, RETADR=0030.(10 marks) 3 (a) Enlist the various machine independent assembler features.(5 marks) 3 (b) With suitable example, explain the use of LTORG assembler directive.(5 marks) 3 (c) Explain the multi pass assembler with example.(10 marks) 4 (a) What are basic functions of loader? Develop an algorithm for a bootstrap loader.(10 marks) 4 (b) What is the difference between linkage editor and linking loader?(4 marks) 4 (c) Explain various data structures used for a linking loader.(6 marks) 5 (a) Explain the relationship between editing and viewing buffers with relevant diagram.(10 marks) 5 (b) Differentiate between tracing and traceback functions in a debugging system.(4 marks) 5 (c) Mention the different precessions for future assembler and compiler consistent interface with debugging system.(6 marks) 6 (a) List the different tables used for macroprocessor. Explain their functions.(8 marks) 6 (b) Explain with example, concatenation of macro parameter and generation of unique labels.(12 marks) 7 (a) Explain the structures of LEX specification with example.(10 marks) 7 (b) What is symbol table? Write a LEX program to implement symbol table.(10 marks) 8 (a) What is YACC? Explain the different sections used in writing the YACC specifications.(10 marks) 8 (b) Explain conflicts in YACC with example.(5 marks) 8 (c) Write YACC program to check whether the given string baaa(n>0) is accepted by grammar or not.(5 marks)