Computer Operating System Questions and Answers

Answer: A

Correct answer: relative organization

In relative organisation the records are numbered from a base of zero, so record \( n \) is found by multiplying \( n \) by the record length - the position is computed rather than looked up. That makes any record reachable in one access, at the price of a fixed record length.

Answer: B

Correct answer: System software

System software is everything that makes the machine usable in itself - the operating system, its device drivers, utilities, compilers and loaders. Application software runs on top of it to do the user’s own work.

Answer: A

Correct answer: synchronize critical resources to prevent deadlock

A semaphore is an integer with atomic wait and signal operations, used to guard a shared resource so that processes take it in a disciplined order. Used correctly - every process taking the semaphores in the same order - it both enforces mutual exclusion and prevents the circular waiting that would otherwise deadlock them.

Answer: D

Correct answer: all of the above

Building the macro processor into pass 1 of the assembler avoids implementing input, output and table handling twice, avoids writing an intermediate file between the two programs, and gives the programmer more flexibility, since macro definitions and assembler statements may be interleaved freely. All three advantages follow from the merge.

Answer: D

Correct answer: Machine independent optimization

Producing a better matrix - improving the intermediate representation by removing common subexpressions, moving invariant code out of loops and folding constants - is done before any target machine is considered, so it belongs to machine-independent optimisation. Machine-dependent work such as register allocation comes later, in code generation.

Answer: D

Correct answer: track the beginning and ending of programs

Boundary registers hold the lower and upper limits of the area a program may use. Every address the program generates is compared against them, and a reference outside the pair is trapped - which is how one program is prevented from reaching into another’s memory.

Answer: D

Correct answer: the language which communicates with the computer using only binary digits

Machine language is the processor’s own code: instructions written as patterns of 0s and 1s that the hardware executes directly, with no translation. It is the only language a computer truly understands; everything else must be translated into it first.

Answer: C

Correct answer: UNIX

Word processing, spreadsheets and desktop publishing are applications - programs that do the user’s own work. UNIX is an operating system, which is system software: it manages the machine so that applications can run on it.

Answer: A

Correct answer: a part of data to be displayed

Scissoring, or clipping, discards the parts of a picture that fall outside the window, so only the portion inside is drawn. It is what lets a small viewport show a region of a much larger drawing without the rest spilling across the screen.

Answer: B

Correct answer: consists of a program and relevant information for its relocation

A relocatable program is accompanied by the information a loader needs to adjust its address-sensitive instructions - a relocation list saying which fields hold addresses. The loader adds the load address to each of them, so the program can be placed wherever there is room.