Chapter 1 - A Tour of Computer Systems

Question 1

What is the difference between a text file and a binary file?

Answer 1

Text files consist exclusively of ASCII characters. All other files are binary files.

Question 2

Who designed the C programming language and when?

Answer 2

C was developed by Dennis Ritchie of Bell Labs around 1969-1973.

Question 3

What is responsible for the translation of a source file to an object file?

Answer 3

The translation is performed by the compiler driver.

Question 4

What four stages does the compilation system consist of?

Answer 4

Preprocessing, compiler, assembler and linker.

Question 5

What is the preprocessor (cpp) responsible for?

Answer 5

For modifying the program according to directives that begin with the # character.

The preprocessor typically generates a .i file.

Question 6

What is the compiler (cc1) responsible for?

Answer 6

Translating a .i text file into a text file with the .s suffix, which contains an assembly language program.

Question 7

What is the assembler (as) responsible for?

Answer 7

Translating a .s file containing assembly language instructions into machine language instructions, stored as a .o file.

Question 8

What is the linker (ld) responsible for?

Answer 8

Merging library object files with a given object (.o) file to produce an executable.

Question 9

Fill in the blank:

______ are electrical conduits that carry bytes of information between components.

Answer 9

Buses are electrical conduits that carry bytes of information between components.

Question 10

What is the term given to the size of data transferred along a bus?

Answer 10

A “word”.

Question 11

Fill in the blank:

The number of _____ in a _____ is a fundamental system parameter.

Answer 11

The number of bytes in a word is a fundamental system parameter.

Question 12

What are standard word sizes for machines today?

Answer 12

4 bytes (32-bit) or 8 bytes (64-bit).

Question 13

What are I/O devices?

Answer 13

The systems connection to the external world (e.g. keyboard, mouse, etc.).

Question 14

In what two ways are I/O devices connected to the I/O bus?

Answer 14

By an adapter or a controller.

Question 15

What is the difference between an adapter and a controller?

Answer 15

A controller is a chip sets in the device itself or on the system’s motherboard.

An adapter is a card that plugs into a slot on the motherboard.

Question 16

What is the main memory?

Answer 16

A temporary storage device that holds a program and the data it manipulates while the processor is executing the program.

Question 17

Fill in the blank:

Main memory consists of a collection of ______ random access memory (____) chips.

Answer 17

Main memory consists of a collection of dynamic random access memory (DRAM) chips.

Question 18

What component is responsible for interpreting instructions stored in main memory?

Answer 18

The central processing unit (CPU).

Question 19

Fill in the blanks:

The _______ _______ is a processor _______ that indicates where a computer is in its program sequence.

Answer 19

The program counter is a processor register that indicates where a computer is in its program sequence.

Question 20

True or false? The entire time the system is awake, a processor repeatedly executes the instruction pointed at by the program counter and updates the program counter to point to the next instruction.

Answer 20

True.

Question 21

What computer component does PC stand for?

Answer 21

Program counter.

Question 22

What is the instruction set architecture?

Answer 22

A simple instruction execution model that a processor appears to operate according to.

Question 23

What does ISA stand for?

Answer 23

Instruction set architecture.

Question 24

Fill in the blanks:

The operations the processor performs revolves around the ____ _______, the ______ ____ and the ________ ____ ____.

Answer 24

The operations the processor performs revolves around the main memory, the register file and the arithmetic logic unit.

Question 25

What is a cache hit/miss?

Answer 25

A cache hit is if the processor is able to find its data in cache memory.

A cache miss is if the CPU tries to find something in cache and it’s not there.

Question 26

What does a cache do?

Answer 26

Stores the most recently used instructions and data in high-speed memory for quick access.

Question 27

How much address space is there in a 32-bit environment?

Answer 27

In 32-bit protected mode, a task or program can address a linear space up to 4GB.

With extended physical addressing, a total of 64 GB could be addressed.

Question 28

What is at the top-level of the memory hierarchy?

Answer 28

Registers.

Question 29

What are L1, L2 and L3 storage devices in a memory hierarchy?

Answer 29

Caches (consisting of static random access memory).

Question 30

What two main purposes does the operating system have?

Answer 30

To protect the hardware from runaway applications.

To provide applications with simple and uniform mechanisms for manipulating low-level hardware devices.

Question 31

What mechanism is used by a single CPU to give the impression that it can execute multiple processes concurrently?

Answer 31

Context switching.

Question 32

What part of the operating system is used to transition from one process to another.

Answer 32

The kernel.

Question 33

What is stored in the ROM?

Answer 33

The BIOS (basic input/output system), i.e. the start-up instructions.

Question 34

What is virtual memory?

Answer 34

An abstraction that provides the process with the illusion that it has exclusive use of the main memory.

Question 35

What six things does the virtual address space of a Linux process consist of?

Answer 35

1. Read-only code and data.
2. Read/write data.
3. Run-time heap (dynamic).
4. A memory-mapped region for shared libraries.
5. User stack (created at run-time).
6. The kernel virtual memory.