Lesson 2: Computer System Structure

Question 1

set of integrated devices that input, output, process, and store data and information

Answer 1

Computer System

Question 2

basic, complete and functional hardware and software setup with everything needed to implement computing performance

Answer 2

Computer System

Question 3

Four Main Structural Elements of a Computer System (PMIS)

Answer 3

Processor, Main Memory, I/O Modules, System Bus

Question 4

[Main Structural Elements of a Computer System] controls the operation of the computer and performs data processing functions

Answer 4

Processor

Question 5

[Main Structural Elements of a Computer System] commonly known as central processing unit (CPU)

Answer 5

Processor

Question 6

[Main Structural Elements of a Computer System] stores data and programs which is typically volatile

Answer 6

Main Memory

Question 7

[Main Structural Elements of a Computer System] moves data between the computer and its external environment

Answer 7

I/O Modules

Question 8

[Main Structural Elements of a Computer System] provides communication among processors, main memory and I/O modules

Answer 8

System Bus

Question 9

startup sequence that starts the operating system of a computer when it is turned on

Answer 9

Booting

Question 10

the initial set of operations that the computer performs when it is switched on

Answer 10

Boot Sequence

Question 11

program whose task is to load a bigger program, such as the operating system

Answer 11

Boot Loader

Question 12

Stages of Linux Boot Process (BMGKIR)

Answer 12

BIOS
MBR
GRUB
Kernel
Init
Runlevel

Question 13

What does BIOS stand for?

Answer 13

Basic Input/Output System

Question 14

What does BIOS do?

Answer 14

—Performs some system integrity checks
—Searches, loads, and executes the boot loader program
—Loads and executes the MBR boot loader

Question 15

What does MBR stand for?

Answer 15

Master Boot Record

Question 16

Where is MBR located?

Answer 16

First sector of the bootable disk

Question 17

Three components of MBR (PPM)

Answer 17

Primary boot loader info (first 446 bytes)
Partition table info (next 64 bytes)
MBR validation check (last 2 bytes)

Question 18

What does MBR do?

Answer 18

Loads and executes the GRUB boot loader

Question 19

What does GRUB stand for?

Answer 19

Grand Unified Bootloader

Question 20

What does GRUB do?

Answer 20

—displays a splash screen, waits for few seconds, if you don’t enter anything, it loads the default kernel image as specified in the grub configuration file
—loads and executes Kernel and initrd images

Question 21

What does Kernel do?

Answer 21

—mounts the root file system as specified in the “root=” in grub.conf
—executes the /sbin/init program

Question 22

what does initrd stand for?

Answer 22

Initial RAM Disk

Question 23

What is initrd?

Answer 23

—used by kernel as temporary root file system until kernel is booted and the real root file system is mounted
—contains necessary drivers compiled inside, which helps it to access the hard drive partitions, and other hardware

Question 24

What does Init do?

Answer 24

—looks at the /etc/inittab file to decide the Linux run level
—identifies the default initlevel from /etc/inittab and uses that to load all appropriate program
—execute ‘grep initdefault /etc/inittab’ on your system to identify the default run level

Question 25

Available run levels

Answer 25

0 – halt 1 – Single user mode 2 – Multiuser, without NFS 3 – Full multiuser mode 4 – unused 5 – X11 6 – reboot

Question 26

What is the default run level?

Answer 26

3 or 5

Question 27

Stages of Normal PC Boot Process (SBIL)

Answer 27

Startup of PC BIOS to POST Identify boot device Load OS

Question 28

Categories of Booting Process (HS)

Answer 28

Hard (Cold) Booting Soft (Warm) Booting

Question 29

[Categories of Booting Process] when computer starts form the very beginning or completely dead state, can be considered as a self-test power-on mode for computers

Answer 29

Hard (Cold) Booting

Question 30

[Categories of Booting Process] restarting the computer and allows the system to load OS again, which means that the system is already turned on from the beginning. Mostly, performing a soft boot up when the PC was not shut down properly or in case of any technical issue while operating it.

Answer 30

Soft (Warm) Booting

Question 31

Two Fundamental Approaches to OS Interface (CG)

Answer 31

Command-line Interface (CLI) Graphical User Interface (GUI)

Question 32

[Two Fundamental Approaches to OS Interface] allows users to directly enter commands to be performed by the operating system

Answer 32

Command-Line Interface (CLI)

Question 33

[Two Fundamental Approaches to OS Interface] allows users to interface with the operating system via icons or graphics by means of point-and-click operations

Answer 33

Graphical User Interface (GUI)

Question 34

Some Advantages of GUI (CUM)

Answer 34

CONFIRM: visually acknowledges and confirms each type of activities performed by the users UNDERSTAND: easy to understand MULTITASKING: enables the users to perform a number of tasks at the same time

Question 35

Rough categories of I/O devices (SUCO)

Answer 35

Storage User Interface Communications Other

Question 36

How devices communicate with the computer

Answer 36

Signals sent over wires or air

Question 37

How devices connect with the computer

Answer 37

Ports

Question 38

common set of wires connecting multiple devices

Answer 38

Bus

Question 39

include rigid protocols for the types of messages that can be sent across the bus and the procedures for resolving contention issues

Answer 39

Bus

Question 40

Bus Types Commonly Found in a Modern PC (PESD)

Answer 40

PCI Bus Expansion Bus SCSI Bus Daisy-chain Bus

Question 41

[Bus Types Commonly Found in a Modern PC] connects HIGH-SPEED HIGH-BANDWIDTH DEVICES to the memory subsystem and the CPU

Answer 41

PCI Bus

Question 42

[Bus Types Commonly Found in a Modern PC] connects SLOWER BANDWIDTH DEVICES, which typically deliver data one character at a time with buffering

Answer 42

Expansion Bus

Question 43

[Bus Types Commonly Found in a Modern PC] connects a number of SCSI devices to a common SCSI controller

Answer 43

SCSI Bus

Question 44

[Bus Types Commonly Found in a Modern PC] a string of devices is connected to each other like beads on a chain, and only one of the devices is directly connected to the host

Answer 44

Daisy-chain Bus

Question 45

Communicate with devices associated with each port

Answer 45

Registers

Question 46

Registers may be 1-4 bytes in size and may include...? (IOSC)

Answer 46

Data-IN Register Data-OUT Register Status Register Control Register

Question 47

[Registers] read by the host to get input from the device

Answer 47

Data-in Register

Question 48

[Register] written by the host to send output

Answer 48

Data-out Register

Question 49

[Register] has bits read by the host to ascertain the status of the device

Answer 49

Status Register

Question 50

[Register] has bits written by the host to issue commands or to change settings of the device

Answer 50

Control Register

Question 51

Another technique for communicating with devices in which certain portion of the processor’s address space is mapped to the device and communications occur by reading and writing directly to/from those memory areas

Answer 51

Memory-Mapped I/O

Question 52

suitable for devices which must move large quantities of data quickly

Answer 52

Memory-Mapped I/O

Question 53

can be used either instead of or more often in combination with traditional registers

Answer 53

Memory-Mapped I/O

Question 54

when does potential problem exists with memory-mapped I/O

Answer 54

if a process is allowed to write directly to the address space used by a memory-mapped I/O device

Question 55

T or F: The processor (CPU) can load instruction only from memory.

Answer 55

True

Question 56

Where does general purpose computers run their programs from?

Answer 56

Main memory (RAM)

Question 57

What is the most common secondary storage?

Answer 57

Magnetic disk

Question 58

Hierarchy of Storage-Device (RCMS-MOM)

Answer 58

Registers Cache Main memory Solid-state disk Magnetic disk Optical disk Magnetic tapes