Section 1- Components of a computer

Question 1

Control Unit

Answer 1

Controls and coordinates the activities of the CPU, directing the flow between the CPU and other devices.

Question 2

Control Bus

Answer 2

A bi-directional bus, transmits command, timing, and specific status information between system components.

Question 3

Data Bus

Answer 3

A bi-directional bus that provides a path for moving data and instructions between system components.

Question 4

Address Bus

Answer 4

Transmits the memory addresses of words that are used as operands in program instructions, so that the data can be retrieved and sent back to the processor.

Question 5

Clock speed

Answer 5

Generates a series of signals, switching between 0 and 1, the length of time between each clock cycle (change from 0 to 1).

Question 6

Number of cores affecting CPU speed

Answer 6

Dual-core has two processors linked together in the same integrated circuit. Twice the power of single-core, it does not always perform twice as fast, as the software might be able to take advantage of both processors.

Question 7

Cache

Answer 7

A small amount of fast memory inside the CPU. Instructions from main memory are copied to the cache, and can be fetched from much quicker than memory if needed again.

Question 8

Pipelining

Answer 8

Allows the next instruction to be fetched at the same time as the processor is performing arithmetic or logic operations, holding them in a buffer close to the processor until the instruction can be performed.

Question 9

Instruction Pipelining

Answer 9

Instructions are moved through the processor, including being fetched, buffered, and then executed.

Question 10

Arithmetic Pipelining

Answer 10

Represents the parts of arithmetic operations that can be broken down and overlapped as they are performed.

Question 11

Stored program concept

Answer 11

Machine code instructions are fetched and executed serially by a processor that performs arithmetic and logical operations.

Question 12

Von Neumann Architecture

Answer 12

The same bus is used to transfer both data and instructions.

A single address bus is used to transfer the addresses of data and instructions.

The same word length is used for all memory.

Question 13

Harvard Architecture

Answer 13

Parallel data and instruction buses may be used.

Instructions and data are held in separate memories.

Used in DSP and in embedded systems.

Question 14

Contemporary processor architectures

Answer 14

Incorporate aspects of both Von Neumann and Harvard architecture.

One main memory is for holding both data and instructions, but CPU cache memory is divided into an instruction cache and a data cache.

Question 15

CISC

Answer 15

A large instruction set is used to complete a task in as few lines of assembly language as possible.

The compiler has very little work to do to translate a high-level language statement into machine-code.

Code is relatively short, and very little RAM is required to store instructions.

Question 16

RISC

Answer 16

Only simple instructions, each taking one clock cycle, can be executed.

The compiler has to do more work to translate high-level code into machine code.

More RAM is required to store the machine code instructions. Each instruction takes the same amount of time.

Pipelining possible 4 instructions will execute at least as fast as the single CISC instruction.

Question 17

Co-processor systems

Answer 17

An extra processor used to supplement the functions of the primary processor. Carries out a limited range of functions.

Question 18

Multi-Core system

Answer 18

Distributing workload across multiple CPU cores, and uses parallel processing capabilities will only work if the software can take advantage of these capabilities.

Question 19

Graphical processing unit

Answer 19

Specialised electronic circuit, manipulates computer graphics, and image processing. Parallel architecture, small efficient cores designed for handling multiple tasks simultaneously. A form of co-processor can hold offloaded compute-intensive parts of an application while the remainder of the code runs on the CPU.

Question 20

What is a Pen-Type Reader (barcode)

Answer 20

A light source and a photo diode are in the tip of a pen.

The tip of pen dragged over the barcode at an even speed.

The photo diode measures the intensity of light reflected and generates a waveform to measure width and space in the barcode.

Question 21

Laser scanner (barcode)

Answer 21

Work the same way as pen scanners, except they use a laser beam as a light source.

Question 22

Camera-based reader (barcode)

Answer 22

Uses a camera and image processing techniques to decode a 1D or 2D barcode. Image scanners can read a barcode on any surface, printed or onscreen, and can also read a code that is damaged or poorly printed.

Question 23

Digital cameras (barcode)

Answer 23

Uses a CMOS sensor, and binary data from each sensor is recorded onto the camera’s memory card so that the image can be reproduced using suitable software on a computer.

Question 24

Radio Frequency Identification (RFID)

Answer 24

Uses an input device to read the signal from an RFID chip, and output to transmit a signal from an active tag. Can pass stored data between the receiver and visa versa.

Question 25

Active Tag

Answer 25

Actively transmits a signal for a reader to pick up, and includes a battery to track things a greater distances.

Question 26

Passive Tag

Answer 26

Rely on radio waves emitted from a reader up to a metre away to provide sufficient electromagnetic power to the card using its coiled antenna. Once energised the transponder inside the RFID tag can send its data to the reader nearby.

Question 27

Output Devices

Answer 27

Take data produced by a computer and turn it into a form humans can understand.

Question 28

LCD monitor

Answer 28

Liquid crystal display- contains groups of red, green, and blue diodes to form each pixel. The screen is back-lit using light-emitting diodes.

Question 29

Secondary storage

Answer 29

Not directly accessible to the processor, and has slower access speeds. Retains its contents when the computer’s power is turned off.

Question 30

Hard Disk

Answer 30

A drive head moves across the disk to access different tracks and sectors. Data is read from or written to the disk when the disk passes under the drive head. Drive head when not in use is parked to one side of the disk in order to prevent damage from movement.

Question 31

Optical Disk

Answer 31

Works by using a high-powered laser to “burn” sections of its surface, making them less reflective (pit). Laser a lower power is used to read the shining light onto the surface and a sensor is used to measure the amount of light reflected back.

Question 32

Name the three types of Optical Disk

Answer 32

CD-ROM, CD-R, AND CD-RW

Question 33

Solid-state disk (SSD)