Chapter 2: Computers

Question 1

A computer consist of (4 components)

Answer 1

1. Central processing Unit (CPU)
2. Input/Output Units (I/O)
3. Main (Primary) memory (storage)
4. Auxiliary (secondary) storage

Question 2

Central Processing Unit (CPU)

Answer 2

• Brain of the computer
• Processes data
• Executes programs stored in main memory by fetching instructions, examining them, and executing them
• Contains the logic of the machine
• Consists of the arithmetic logic unit (ALU), control unit, and two registers (Instruction and program counter)

Question 3

Logic

Answer 3

• Ability of a computer to follow instructions

- Stored in Central Processing Unit (CPU)

Question 4

Central Processing Unit (CPU) consists of (3 things)

Answer 4

1. Control unit
2. Arithmetic Logic Unit
3. Registers (2 of them: instruction and program counter)

Question 5

Control unit of a Central Processing Unit (CPU)

Answer 5

• Fetches program instructions (e.g. PRINT, INPUT) from main memory and determines their type and supervises their execution.
• Tells the computer what to do
• Ex: Such as instructing the computer which device to read or send output to

Question 6

Arithmetic/Logic Unit (ALU) of a Central Processing Unit (CPU)

Answer 6

Performs operations: (+,-,*,/) and comparisons (,=) needed to carry out the instructions

Question 7

Registers In a Central Processing Unit (CPU)

Answer 7

• Small very high-speed storage used to store temporary results and certain control information
• Instruction and Program counter registers

Question 8

Instruction Register

Answer 8

Holds the instruction which is currently being executed

Question 9

Program Counter (Instruction Location Counter) (Address Register)

Answer 9

Points to the instruction which will be executed next

Question 10

Computer Program (Also called source code)

Answer 10

• Step-by-step directions for performing a specific task (instructions)
• Written in a language the computer can understand
• Also called a source code
• Source code must be translated into object code, consisting of binary 0s and 1s

Question 11

Other things computer have

Answer 11

• Hardware: Physical devices such as keyboards, monitors, and processing units
• Software: Programs written in computer languages
• Single or multiprocessors (multiprocessing: use of 2+ CPU’s in a computer system)

Question 12

Bus

Answer 12

Link (wire) between devices connected to the computer

Question 13

Disk Drive

Answer 13

Peripheral device (device that connects to the computer) for recording, storing, and retrieving information

Question 14

CPU case (computer chassis/tower)

Answer 14

• Enclosure containing the computer’s main components

- Also called computer chassis or tower

Question 15

Motherboard

Answer 15

Main circuit board containing connectors for attaching additional boards

Question 16

3 basic operations of a computer

Answer 16

1. Arithmetic operations
2. Logical operations
3. Storage and retrieval operations. Data is stored in bits

Question 17

Main/core/primary Memory

Answer 17

• Stores data and information, application programs, and operating systems and other system software
• Volatile (Contents are lost when electrical power is turned off)

Question 18

Secondary Memory

Answer 18

• Nonvolatile (contents are not lost when computer is turned off)
• Holds data when the computer is off or during course of a program’s operation
• Serves as archival storage

Question 19

Random Access Memory (RAM) = Read-write memory

Answer 19

• Type of main memory device
• Volatile
• Data can be read from and written to
• Known as read-write memory
• Direct, find programs easily, open files, running programs

Question 20

Cache RAM

Answer 20

• Stores recently accessed memory
• Resides on the processor
• Type of RAM (type of main memory)

Question 21

Read Only Memory (ROM)

Answer 21

• Type of secondary memory
• Nonvolatile
• Data cannot be written to it
• Color computer, programers read first
• Includes Basic Input Output System (BIOS) information and computer system’s clock
• Programmable read only memory (PROM), contents are permanent
• Erasable programmable read-only memory (EPROM), contents can be erased

Question 22

3 types of Secondary Memory Devices (Hardware)

Answer 22

• Magnetic disks: Used for random-access processing. Data can be accessed in any order
• Magnetic tape: Stores data sequentially, Ex: cassette tape
• Optical disks: Uses laser beams to access and store data, CD’s, DVDs

Question 23

Cloud storage

Answer 23

• Storage which is used for online storage and backup
• Involves multiple virtual servers that are hosted by 3rd parties
• Customers buy space from 3rd parties depending on needs

Question 24

Server

Answer 24

Computer and all the software for managing network resources and offering services to a network

Question 25

Software

Answer 25

- All of the programs that run a computer system - System software works in the background, takes care of tasks such as deleting waste files Ex: Operating system like Windows - Application software performs specialized tasks. Ex: Word processing, spreadsheet, database, presentation, graphics

Question 26

Operating System (OS)

Answer 26

- Set of programs for controlling and managing computer hard and software - Provides interface between computer and user - Is an example of system software - Consists of Control programs (used to manage hardware) and supervisors programs (kernel) used to control all other programs in the operating system (software)

Question 27

Supervisor program (the kernel)

Answer 27

- Responsible for controlling all other programs in the operating system (OS), i.e. the programs that control programs don't control - Known as the kernel

Question 28

System

Answer 28

- Programers (human) -> System Analyst (human) -> End users (human) - System has goal (plan goal, look at data) design systems for end users, output

Question 29

America Standard Code for Information Interchange (ASCII)

Answer 29

- Used for personal computers - Data code for text files, PC applications, and the Internet - EBSDIC - Defines up to 128 characters

Question 30

Bit

Answer 30

= 2 Binary Digit Single value of 1 or 0

Question 31

Byte

Answer 31

= 8 bits | - Used to represent one character (abc, special characters, numbers)

Question 32

Storage byes order

Answer 32

1. Kilobyte (KB): 10^3 2. Megabyte (MB): 10^6 3. Gigabyte (GB): 10^9 4. Terabyte (TB): 10^12

Question 33

Optical character reader (OCR)

Answer 33

Mechanical or electronic conversion of images of typed, handwritten or printed text into machine-encoded text, whether from a scanned document, or a photo of a document

Question 34

Magnetic ink character recognition (MICR) system

Answer 34

Used to verify the legitimacy or originality of paper documents

Question 35

Optical mark recognition (OMR) system

Answer 35

Process of capturing human-marked data from document forms such as surveys and tests.

Question 36

Classes of computers (4)

Answer 36

1. Subnotebooks and notebooks 2. Personal and minicomputers 3. Mainframes 4. Supercomputers

Question 37

Computer languages

Answer 37

1. First Gen: 0s and 1s 2. Second gen: Higher level, short codes, mnemonics 3. High level: Web, internet 4. 4GLS: Macro codes 5. 5GLS: Uses artificial intelligence

Question 38

Redundant Array of Independent Disks (RAID) system

Answer 38

- Collection of disk drives used for fault tolerance and up performance, found in large network systems/companies - If one disk fails, data isn't lost, back up storage

Question 39

Computer does 3 things

Answer 39

1. Accepts data as input 2. Processes data 3. Outputs information

Question 40

3 factors affecting power of computers

Answer 40

1. Seed (millisecond 1/1,000, microsecond 1/1,000,000, nanosecond, picosecond 1/1,000,000,000) 2. Accuracy 3. Storage (saving data in computer memory) and retrieval capabilities (accessing data from memory)

Question 41

Input/output devices

Answer 41

Input devices: Send data and information to computers Ex: Mouse, touch screen Output devices: Capable of representing information from a computer Ex: Visual, audio, digital, plotters convert output into graphics, voice synthesizers convert output into voice

Question 42

True or false: Computers can be used in transaction-processing operations that involve enormous values of data

Answer 42

True

Question 43

Memory stores (3 things)

Answer 43

1) The operating systems and other system software that control or maintain the computer and its devices 2) Application programs that carry out specific task 3) The data being processed by application programs and the resulting information

Question 44

True or false: Computers and communication systems use data codes to represent and transfer data between computers and network systems

Answer 44

True

Question 45

CD-ROMs and DVDs are examples of

Answer 45

Optical disks

Question 46

True or false: A byte is a single value of 0 or 1

Answer 46

False, 1 byte = 8 bits and 1 bit=a single value of 0 or 1

Question 47

True of false: In the binary number system, 2 is used to represent the value 2

Answer 47

False, the number 2 is used to represent either 0 or 1