Computer Operating System Questions and Answers

Answer: D

Correct answer: Extended Memory

HIMEM.SYS is the extended memory manager: it takes charge of the memory above 1 MB and hands it out through the XMS interface, which is why it must be loaded before EMM386, SMARTDRV or DOS=HIGH can do anything.

Answer: A

Correct answer: a set of programs which controls computer working

An operating system is the body of programs that controls the machine - scheduling the processor, allocating memory, managing files and driving devices - and presents that machine to users and to other programs. Translating a high-level language is the compiler’s work.

Answer: C

Correct answer: is an access to a page not currently in memory

A page fault is the trap raised when a program references a page that is not resident: the hardware interrupts, the operating system finds the page on disk, brings it into a free frame - evicting another page if necessary - updates the page table and restarts the instruction. It is a normal event in a paged system, not an error.

Answer: B

Correct answer: CONFIG.SYS, AUTOEXEC.BAT

DOS reads CONFIG.SYS first, loading the device drivers and setting FILES, BUFFERS and the rest, then loads COMMAND.COM, which runs AUTOEXEC.BAT. The order matters: drivers must be in place before the commands that use them are executed.

Answer: C

Correct answer: operating environment

An operating environment is a layer placed over the operating system to make it easier to use - a menu shell or a graphical environment such as early Windows over MS-DOS - presenting the same facilities in a friendlier form. Timesharing and multitasking are things the operating system does, not aids to using it.

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: must be "loaded" before execution

Object code is the machine code a translator produces, but it is not yet runnable: external references must be resolved by the linker and the addresses relocated to wherever the program is placed, which the loader does before control is passed to it.

Answer: A

Correct answer: Assembly and output

Turning symbolic labels into actual addresses and emitting the machine instructions is the last phase of compilation - assembly and output. Code generation has already chosen the instructions; this phase fixes their addresses and writes the object module.

Answer: B

Correct answer: 1

A semaphore guarding a critical section starts at 1: the first process to call wait() takes the count to 0 and enters, and every other process blocks until that one calls signal(). Only one process is inside at a time, which is exactly mutual exclusion.

Answer: A

Correct answer: config.sys

A driver ending in .SYS is loaded by a DEVICE= line in CONFIG.SYS, which DOS reads early in the boot before the command interpreter starts. The .COM form of the same driver would instead be run from AUTOEXEC.BAT.