Chapter 3: Hardware

Question 1

Define CPU
Central processing unit

Answer 1

responsible for the execution or processing of all the instructions and data in a computer

Question 2

Define Von Neumann Architecture

Answer 2

a type of computer architecture which introduced the concept of the stored program in the 1940s

Question 3

Define ALU

Answer 3

the component of the CPU that carries out all arithmetic and logical operations

Question 4

Define ACC [Accumulatr]

Answer 4

temporary general-purpose register that stores numerical values at any part of a given operation

Question 5

Define MAR (memory address register)

Answer 5

a register that stores the address of the memory location currently being read from or written to

Question 6

Define CIR [current instruction register ]

Answer 6

a register that stores the current instruction being decoded and executed

Question 7

Define MDR [memory data register]

Answer 7

a register that stores data that has just been read from memory or data that is about to be written to memory

Question 8

Define PC [Program couunter]

Answer 8

a register that stores the address where the next instruction to be read can be found

Question 9

Define control unit

Answer 9

the component of a computer’s CPU that ensures synchronisation of data flow and programs throughout the computer by sending out control signals along the control bus

Question 10

Define system clock

Answer 10

produces timing signals on the control bus to ensure synchronisation takes place

Question 11

Define clock cycle

Answer 11

s temporary memory using static RAM to hold frequently used data/instructions by the CPU thereby increasing CPU performance. More generally, cache means any area of storage used to quickly access frequently-used data - other examples include web cache, database cache, DNS cache

Question 12

Define register

Answer 12

a temporary component in the CPU which can be general or specific in its use; it holds data or instructions as part of the Fetch–Decode–Execute cycle

Question 13

Define address

Answer 13

a label for a memory location used by the CPU to track data

Question 14

Define memory location

Answer 14

a numbered place in memory where values can be stored

Question 15

Define system bus

Answer 15

a connection between major components in a computer that can carry data, addresses or control signals

Question 16

Define address bus

Answer 16

the system bus that carries the addresses throughout the computer system

Question 17

Define data bus

Answer 17

the system bus that allows data to be carried from CPU to memory (and vice versa) or to and from input/ output devices

Question 18

Define control bus

Answer 18

– the system bus that carries signals from control unit to all other computer components

Question 19

Define unidirectional

Answer 19

can travel in one direction only

Question 20

Define bidirectional

Answer 20

can travel in both directions;

Question 21

Define over clocking

Answer 21

changing the clock speed of a system clock to a value higher than the factory/recommended setting

Question 22

Define core

Answer 22

a unit on a CPU made up of an ALU, control unit and registers

Question 23

Define dual core

Answer 23

A CPU containing 2 cores

Question 24

Define Fetch-Execute-Decode

Answer 24

– a cycle in which instructions and data are fetched from memory, decoded and finally executed

Question 25

Define BIOS

Answer 25

– a suite of programs on firmware that are used to perform the initialisation of a computer system during the boot-up process

Question 26

Define opcode

Answer 26

– part of a machine code instruction that identifies what action the CPU has to perform

Question 27

Define operand

Answer 27

part of a machine code instruction that identifies what data is to be used

Question 28

Define instruction set

Answer 28

the complete set of machine code instructions used a particular microprocessor

Question 29

Define embedded system

Answer 29

a combination of hardware and software designed to carry out a specific set of functions

Question 30

Define barcode

Answer 30

a series of dark and light lines of varying thickness used to represent data; the code has to be scanned using laser or LED light source

Question 31

Define keyfield

Answer 31

the field that uniquely identifies a record in a file

Question 32

Define QR code

Answer 32

a matrix of dark and light squares which represent data

Question 33

Define frame QR code

Answer 33

a type of QR code that includes a space for advertising

Question 34

Define DAC

Answer 34

device that converts digital data into electric currents that can drive motors, actuators and relays

Question 35

Define ADC

Answer 35

a device that converts analogue data (for example, data read from sensors) into a form understood by a computer

Question 36

Define CCD

Answer 36

a light sensitive cell made up of millions of tiny sensors acting as photodiodes

Question 37

Define virtual keyboard

Answer 37

an onscreen keyboard which uses the features of the touch screen to emulate a physical keyboard

Question 38

Define touch screen

Answer 38

a screen that allows the user to select or manipulate a screen image using the touch of a finger or stylus; touch screens most frequently use capacitive, infra- red or resistive technology

Question 39

Define RSI (repetitive strain injury)

Answer 39

pain felt in the muscles, nerves and tendons caused by a repetitive action (for example, excessive clicking of a mouse button over a period of time)

Question 40

Define optical mouse

Answer 40

a pointing device that uses a red LED to track the movement of the device and then relays its coordinates to a computer

Question 41

Define pointing device

Answer 41

an input device that allows the user to control the movement of an onscreen cursor or to allow onscreen selection by clicking a button on the device

Question 42

Define CMOS

Answer 42

a chip that generates an electric current (or pulses) when light falls on its surface

Question 43

Define DSP

Answer 43

a processor that calculates, for example, the coordinates of a pointing device based on the pulses of electricity received

Question 44

Define optical character recognition

Answer 44

technology that can convert hard copy text or images into a digital format to be stored in a computer memory

Question 45

Define CAD

Answer 45

software used to create drawings

Question 46

Define CT scanner

Answer 46

technology that can create a 3D image of a solid object by slicing up the object into thin layers (tomography)

Question 47

Define capacitive touch screen

Answer 47

a type of touch screen that uses the change in the screen’s capacitance (the ability to store an electrical charge) when it is touched by a finger or stylus

Question 48

Define infra-red touch screen

Answer 48

a type of touch screen that uses infra-red beams and sensors to detect where the screen has been touched

Question 49

Define resistive touch screen

Answer 49

a type of touch screen that uses two conductive layers which make contact where the screen has been touched

Question 50

Define actuator

Answer 50

an output device that converts electrical energy into mechanical movement

Question 51

Define DMD

Answer 51

a chip that uses millions of tiny mirrors on its surface to create a video display

Question 52

Define thermal bubble

Answer 52

inkjet printer technology whereby tiny resistors create heat and form an ink bubble which is ejected onto paper in an inkjet printer

Question 53

Define piezoelectric crystal

Answer 53

a crystal located in an ink reservoir within an inkjet printer; the crystal vibrates and forces ink out onto paper

Question 54

Define direct 3D printing

Answer 54

a 3D printing technique in which the print head moves in the x, y and z directions