Section 1 - Components of a computer Flashcards
1
Q
What is the CPU also known as?
A
The CPU is also known as the processor
2
Q
What components make up the CPU?
A
The CPU is made up of the control Unit, Buses, Arithmetic Logic Unit, and also dedicated registers
3
Q
What does the Control Unit do?
A
The control unit controls and coordinates the activities of the CPU, as well doing the FDE cycle and storing the resulting data back in memory or registers
4
Q
What is a Bus?
A
A bus is a set of wires which connect two or more components of a computer.
5
Q
What are the 3 categories of buses?
A
Data Bus, Control Bus, Address Bus, together they are known as the System Bus
6
Q
What does the Data Bus do?
A
The data bus is in charge of moving data around the computer
7
Q
What does the Control Bus do?
A
The control bus sends control signals, which are used to synchronise the computer
8
Q
What does the Address bus do?
A
The address bus transfers addresses around the computer
9
Q
How many Control lines does the Control bus have?
A
6
10
Q
What are these control lines?
A
Bus Request, Bus Grant, Memory Write, Memory Read, Interrupt Request, Clock
11
Q
What is the Bus Request Control Line?
A
Indicates that a device is requesting the use of a data bus
12
Q
What is the Bus Grant Control Line?
A
Indicates that the CPU has granted access to the data bus
13
Q
What is the Memory Write Control Line
A
Causes data on the data bus to be written into the addressed location
14
Q
What is the Memory Read Control Line?
A
Causes data from the addressed lcoation to be placed on the data bus
15
Q
What is the Interrupt request control line?
A
Indicates that a device is requesting access to the CPU
16
Q
What is the Clock Control Line
A
The Clock Control Line is used to synchronise operations.
17
Q
What is the Arithmetic-Logic Unit
A
The Arithmetic Logic Unit is a special register which performs arithmetic and logical operations on data, before depositing it in the Accumulator.
18
Q
What are the 5 main Registers inside of a CPU?
A
Accumulator, Program Counter, Current Instruction Register, Memory Address Register, Memory Data Register
19
Q
What is the Accumulator
A
The Accumulator is where all calculations take place
20
Q
What is the Program Counter
A
The Program Counter holds the address of the next instruction to be executed.
21
Q
What is the Current Instruction Register?
A
The current instruction register holds the current instriction being executed, divided into Operand and Opcode
22
Q
What is the memory address register?
A
The Memory Address Register holds the address of the memory location from which data is to be fetched from or to which data is to be written
23
Q
What is the Memory Data Register?
A
The memory Data Register is used to temporarily store the data read from or written to memory.
24
Q
What is the Fetch-Decode-Execute Cycle?
A
The Fetch-Decode-Execute Cycle is a sequence of operations involved in executing an instruction.
25
What happens in the Fetch Phase of the Fetch-Decode-Execute Cycle?
In the Fetch Phase of the Fetch-Decode-Execute Cycle, a total of three steps occur, these are:
1. The address of the next instruction is copied from the Program counter to the memory address register.
2. The instruction heald at that address is copied to the memory data register. Simultaneously, the content of the Program Counter is incremented so that it holds the address of the next instruction.
3. The contents of the Memory Data Register are copied to the Current Instruction Register.
26
What happens in the Decode Phase of the Fetch-Decode-Execute Cycle?
In the Decode Phase of the Fetch-Decode-Execute cycle, only one instruction is carried out, this instruction is:
4. The instruction held in the CIR is decoded, and split into opcode and operand.
27
What happens in the Execute Phase of the Fetch-Decode-Execute Cycle?
5. The appropriate instruction/opcode is carried out on the operand
28
What is the Opcode?
The Opcode is used to determine the type of instruction and what hardware to use to execute it
29
What is the Operand?
The Operand can hold 3 different things, these are:
1. The address of the data to be used with the operation, which will be passed to the MAR
2. The actual data to be operated on, which will be passed to the MDR
3. The data to be operated on, which will be passed to the ALU/Accumulator
30
What are the 3 factors which affect the Processor's performance?
1. Clock Speed
2. The number of cores
3. The amount and type of cache memory
31
How does clock speed affect the processor's performance?
Clock Speed affects the processor's performance due to the fact that it works to synchronise the PC's components, so if your computer has a slow clock speed, your computer would run slower since it takes longer to execute an instruction
32
How does having more Cores affect processor Performance?
having more Cores effects processor Performance
33
How does the amount of cache memory affect the processor's performance?
The amount of cache memory affects the processor's performance due to the fact that cache memory is very fast storage location inside the CPU, so having more of this means more data can be processed quickly
34
What are the 3 levels of cache?
Level 1, Level 2, Level 3
35
What is Level 1 Cache Memory?
Level 1 Cache memory is extremely fast but small (between 2-64KB)
36
What is Level 2 Cache Memory?
Level 2 Cache memory is fairly fast but medium sized (256KB - 2MB)
37
What is level 3 Cache Memory?
Level 3 Cache memory is slower than the other two but marge larger, being between 10MB and 64MB
38
what is Pipelining?
Pipelining is a technique used by processors to improve performance, it works by making it so that the computer can be fetched while the computer is executing an instruction, speeding up the Fetch-Decode-Execute cycle.
39
What are the two types of Pipelining?
Arithmetic Pipelining and Instruction Pipelining
40
What is Arithmetic Pipelining?
Arithmetic Pipelining represents the parts of an arithmetic operation that can be broken down and overlapped as they are performed.
41
How does Pipelining occur?
While the computer is executing an instruction, the Busses find the next piece of memory and hold this data close to the processor in a buffer zone, significantly cutting down on the time it takes to obtain data.
42
What is the Address Bus?
The Address Bus is a Bus that transfers the address of data that the processor needs, with the width of the address bus determining the maximum possible memory capacity of the system.
43
What is the Data Bus?
The data bus transmits the data held in a word of memory between processor components and memory. It splits the data into operand and opcode, with the operand containing the address of the data, while the opcode contains the data itself.
44
What does the von Neumann architecture specify?
The von Neumann architecture specifies the basic components of the computer and processor in which a shared memory and bus is used for both data and instructions.
45
What is the stored program concept?
The stored program can be defined as machine code instructions are fetched and executed serially by a processor that performs arithmetic and logical operations.
46
How is the Stored Program concept carried out?
The program being used must be a resident in main memory, if it is, the machine code instructions are fetched from memory one at a time, decoded and executed in the processor.
47
How does the Von Neumann machine Transfer data and instructions?
The Von Neumann machine transfers data and instructions using the data, as well as using a single address bus to transfer the addresses of the data and instructions.
48
What are the two architectural concepts?
Von Neumann and Harvard.
49
what is the Harvard Architecture?
Harvard architecture is where the computer physically separates memories for instructions and data.
50
Where is Harvard Architecture largely used?
Harvard Architecture is largely used for Digital Signal Processing systems
51
What are Digital Signal Processing Applications?
DSP Applications include audio and speech signal processing, sonar and radar signal processing, biomedical signal processing, seismic data processing and digital image processing.
52
What are the 3 features of Harvard Architecture?
In Harvard Architecture, the two different memories can have different characteristics, such as one being exclusively read-only memory and another being read-write memory.
The two different memories may also be of different sizes, allowing the memory which stores the data to have a larger storage capacity than the memory which holds the instructions.
The Address Bus can be wider than the data bus.
53
How is Harvard Architecture faster than Von Neumann Architecture?
Harvard Architecture is faster than Von Neumann due to the fact that data and instructions can be fetched in parallel instead of competing for the same bus.
54
What is a Complex Instruction Set Computer?
The Complex Instruction Set was a computing architecture used before Von Neumann and Harvard, it used a large Instruction set to accomplish tasks in as few lines of assembly language as possible.
55
What is an advantage of CISC processors compared to modern day processors?
Because the compiler has very little work to do to translate a high-level language statement into machine code, and because the code was relatively short, Very little RAM was needed to store the instructions.
56
What is a disadvantage of CISC processors compared to modern day processors?
A disadvantage is that many specialised instructions had to be built into the hardware even though only 20% of them were used in the average program.
57
What is the Reduced Instruction Set Computer?
RISC architecture is the opposite of CISC, it stored only simple instructions, with each taking a single clock cycle to be executed.
58
What is an advantage of RISC Processors when compared to Modern Day Processors?
All functions carried out with a number of simple instructions, make sure there are no instructions which are rarely used.
59
What is a Disadvantage of RISC Processors?
The Compiler has to do more work to translate high-level code into machine code, and more RAM is required to store the machine code instructions.
60
What is a Coprocessor System?
A co-processor system is a system which uses an extra processor to supplement the functions of the primary processor (the CPU).
61
Where would a co-processor system be used?
A co-processor system would be used to perform floating point arithmetic, graphics processing, digital signal processing and other functions.
62
What is a Multi-core CPU?
A Multi-core CPU is a CPU that is able to distribute the workload across multiple CPU cores, achieving significantly higher performance in the process.
63
What is a GPU?
A GPU ios a specialised electronic circuit which is very efficient at manipulating computer graphics and image-processing.
64
What is the GPU made up of?
Thousands of smaller, more efficient cores designed for handling multiple tasks simultaneously.
65
What is an advantage of the GPU?
tasks where processing of large blocks of visual data is done simultaneously is much easier for a GPU than it would be for a CPU.
66
What are the two types of barcodes?
Linear Barcodes and 2D Barcodes
67
What are the different ways of reading barcodes?
Pen-Type Readers, Laser Scanners, Camera-based Reader and Digital Cameras.
68
What is a Pen-Type Barcode Reader?
Uses a light source and a photo-diode are used to read the intensity of the ligh reflected back from the barcode, from this a waveform is generated which is used to measure the width of the bars and spaces in the barcode.
69
What is an Advantage of a Pen-Type Barcode Reader?
They are the most Durable, and can be tightly sealed against dust, dirt and other environmental hazards, small size and low weight makes them easily portable.
70
What is a Disadvantage of a Pen-Type Barcode Reader?
Must come in direct contact with the Barcode.
71
What is laser Scanner Barcode Reader?
Works in the same manner as a Pen-Type Reader except a laser beam is used as the lightsource.
72
What is a Camera-Based Barcode Reader?
Uses a camera and image processing techniques to decode a 1D or 2D code.
73
Where are Camera-Based barcode Readers used?
Age Verification, Coupons, Event Ticketing, downloading of files.
74
What is a Digital Camera Based Barcode Reader?
Uses CCDs or CMOS (Complementary Metal Oxide Semiconductor) sensor comprising of millions of tiny light sensors arranged in a grid. the binary data of each sensor is recorded onto the camera's memory so the image can be reproduced.
75
What is Radio Frequency Identification (RFID)?
RFID is used as both an input and output device, they are used as an input device to read the signal from an RFID chip and as an output device to transmit a signal from an active tag.
76
What are the two types of RFID chips?
Active Chips and Passive Chips
77
What is an Active RFID Chip?
Physically larger chips which require a battery to power the tag to actively transmit a signal for a reader to pick up. Used to track things from a further distance.
78
What is a Passive RFID Chip?
Much Cheaper to produce, 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, data can be sent to the nearby reader. Used for tagging items or for smart card.
79
What is an output device?
An output device takes data produced by the computer and turns it into a form humans can understand. e.g. Visual/Sound
80
What are the two 'screen' type output devices?
LCD (Liquid Crystal Display) & OLED (Organic LED)
81
What is an LCD Screen
Liquid Crystal Display monitors contain groups of red, green and blue diodes to form each pixel, and used LEDs to provide the light for the diodes.
82
What are the advantages of an LCD Screen?
They reach their maximum brightness almost instantly
The image is sharper with more realistic and vivid colours
They produce a brighter light which leads to better picture definition
Since LEDs are very small, screens can be much thinner in construction
They last almost indefinitely, making the screens much more reliable
They consume very little power
83
What is an OLED Screen?
Brighter, thinner and lighter than traditional LCD or LED screens, and use organic LEDs to display information, hence the name.
84
What are the advantages of an OLED Screen?
Made of plastic rather than glass, so much more flexible than LCD screens
Much thinner
Brighter and need no backlighting, so they consume less power
Respond 200 times faster than LCD screen to changes in data.
produce truer colours through a much bigger viewing angle.
85
What are the four 'Printer' type output devices?
Laser Printers, Inkjet Printers, Dot Matrix Printers, 3-D Printers
86
What is a Laser Printer?
Laser Printers work by having a conveyor belt for the printer, which goes through a number of processes, first whatever is wanted to be printed onto the paper is etched onto a print drum using a laser unit, before this ink is fused with the paper, this paper is then outputted from the printer.
87
What are the advantages of Laser Printers?
Very Fast and produce High Quality printing
88
What are the disadvantages of Laser printers?
very expensive to run for colour prints, with the paper needing to be put through the process each time for each colour applied, slowing down the print.
Quality of the print is limited by the Print Drum, and as this usually is at around 1200 dpi, Photorealistic images are impossible
89
What is an Inkjet Printer?
Inkjet printers work by spraying minute dots of ink onto paper to create an image.
90
What is the advantage of an Inkjet Printer?
Can create photo-realistic images.
Cheaper than laser printers
91
What are the disadvantages of an Inkjet Printer?
Ink Cartridges need to be replaced frequently
Slower than Laser Printers
92
What is a Dot Matrix Printer?
Also known as impact printers, they work by having a matrix of pins which strike the surface of the paper through an inked ribbon to form letters.
93
What are the advantages of Dot Matrix Printers?
Operate in Dirty and damp environments
94
What are the disadvantage of Dot matrix printers?
Noisy, slow and a poor quality of printing.
95
What is a 3D Printer?
Used to create physical objects, rather than print on paper.
96
What are the advantages of a 3D Printer?
Can create spare parts for obsolete equipment and prototypes of new products, as well as one-off items. Mostly used where buying a part from a manufacturer would be too time consuming or impossible due to the part no longer being in production.
97
What are other types of Output Devices?
Multimedia Projectors, Computer Speakers & Actuators
98
What is a multimedia Projector?
Projects information onto a surface when linked to a computer or other input device.
99
What are the advantages of a Multimedia Projector?
Able to make small screens more visible to a number of people
100
What is a Computer Speaker
Outputs sound for devices which do not have one built in.
101
What is an Actuator?
Motors used commonly in conjunction with sensors to control a mechanism, they can be used to open a window or a valve, starting or stopping a pump, as well as other things.
102
What is a secondary storage device?
A secondary storage device is a storage device not directly accessible to the processor and has slower access speeds, but can be used to store additional data which is too large for the actual computer.
103
What are the 5 types of Secondary Storage Devices?
Hard Disks, Optical Disks, Solid-State Disks, Ram & Rom, Virtual Memory
104
What is a Hard Disk?
A Hard Disk uses rigid rotating platters coated with magnetic materials to polarise iron particles to either polarise them to a north or south states, which represent a 1 or a 0. A Drive head then runs over to platter to read the data stored by these iron particles.
105
What are the advantages of a Hard Disk?
Huge Capacity (up to 640GB)
Small and Portable
Very Cheap
Fairly Fast to access data.
106
What is an Optical Disk?
3 Different Formats (CD-ROM, CD-R & CD-RW) which coincide with Read Only, Recordable and Rewritable.
Works by using a high powered laser to "burn" sections of its surface making them less reflective. A low powered laser then runs along the disk and is used to measure the amount of light reflected back and translate that into data.
107
What are the advantages of an Optical Disk?
Very Cheap
Portable
108
What are the disadvantages of an Optical Disk?
Easily Corrupted an damaged by excessive sunlight or scratches.
109
What is a Solid-State Disk?
A solid-state disk stores data in pages which are typically 4 Kilobytes, and these pages are then grouped up into a much larger block, with all of this data being stored as NAND memory cells, which cannot be overwritten and must instead be erased before more data can be written to the same location.
110
What are the advantages of Solid-State Disks?
Faster access speeds than hard disks
Consume far less power
silent in operation, and very light and portable.
111
What are the two kinds of internal memory of a computer?
Random Access memory (RAM) and Read-Only Memory (ROM)
112
What does RAM store?
RAM is used to store programs and data that are currently being used. It is volatile, meaning that it's contents are lost when it stops receiving power.
113
What does ROM store?
ROM is used to hold information that needs to be permanently in memory. Examples of this are things necessary to boot up the computer or whatever embedded system is using the ROM.
114
What is Virtual Storage?
Virtual Storage is what is created when the computer's RAM is not large enough to store all these program simultaneously, it is where the hard disk is partitioned to create a new storage location.
115
What are the advantages & Disadvantages of having Virtual storage?
Frees up space in the RAM, but has slower read & write speeds.
