Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

When u restart the router > 4 - Computer Systems > Flashcards

4 - Computer Systems Flashcards

Yhhhhh

1
Q

Hardware

A

The physical components that make up a computer system, including processors, memory, storage, and input and output devices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Software

A

The programs that run on a computer, including operating systems, utility programs and application software (which includes mobile apps)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Logic

A

In computer science, ‘logic’ refers to producing Boolean outputs (0 or 1; true or false) based on combinations of Boolean inputs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

AND

A

all inputs must be ‘1’ for the output to be ‘1’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

OR

A

If either input, or both inputs, is ‘1’, the output is ‘1’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

NOT

A

the output is simply the opposite of the output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Truth Table

A

Can be used to map Boolean logic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

System Software

A

Programs that are needed for effective communication with the hardware, and for launching application software. E.g:

  • OS, such as windows and Android
  • Utility Software, such as antivirus and compression software
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Application software

A

Programs launched from the OS, by the user, to perform a specific task or group of tasks. E.g:

  • Desktop apps such as browsers and word processing packages
  • Mobile apps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Operating system

A

OS. A piece of system software that acts as an interface between the user and the hardware, managing all hardware and all other software. If another piece of software is to be launched, it will be launched from the OS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

OS complexity

A

OS are complex pieces of software, often requiring many years and many people to develop them. The reason that they are complex is simply that computers are complex, with many hardware and software that requires management.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Things managed by the OS

A
  • Processors
  • Memory
  • I/O devices
  • Apps
  • Security
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

OS: Processor(s)

A

The operating system decides…

  • which processes will be carried out by which processors
  • if multiple processes are running, which one the processor should handle next
  • how long a time scale a process should be given, i.i how long before the processor’s attention switches to the next process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

OS: Memory

A

The OS…

  • loads programs and data from backup store to main memory
  • removes unneeded programs and data to make room for more
  • manages virtual memory where part of secondary storage is used as an overflow area for main memory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

OS: I/O devices

A

The OS…

  • acts as a go between, passing data from input to application software or application software to output
  • manages device drivers, which are programs telling the OS how to communicate with attached input/output devices
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

OS: Apps

A

The OS…

  • communicates between app software and hardware
  • processes requests from app software for resources, such as network connection or a remotely stored file
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

OS: Security

A

The OS can…

  • manage multiple user accounts, keeping the user’s data separate
  • automatically back up data, thereby increasing its security
  • handle usernames and passwords to prevent unauthorised access
  • recognise one user as an admin, who would have greater access rights
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Utility Software

A

programs that keep the computer functioning efficiently, perhaps by freeing up storage space, removing viruses or ensuring the files are backed u[

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Utility: Compression

A

Reducing the size of a file so that it can be stored using less space or transmitted more quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Utility: Defragmentation

A

Moving separate parts of a file physically together, to speed up disk access

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Utility: Backing up

A

Creating a copy of files, either on the same disk, on a backup device or in the cloud
Backing up can be either full or incremental:
- Full backup involves creating a copy of all files
- Incremental backup involves creating a copy only of files that have been created or edited since the last back-up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Utility: Encryption

A

Allowing for data to be scrambled in order to prevent unauthorised individuals from understanding any files that they see. This might be for secure storage or secure transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Von Neumann Architecture

A

Data is input, processed by the CPU, which has several components of its own, and output. There is also memory allowing data to be stored. Buses act as connections between them.

There is:

  • An input
  • A CPU
  • An Arithmetic Logic Unit (ALU)
  • A Register
  • A Control Unit
  • Memory
  • An Output
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

The model of Von Neumann Architecture

A

The model defines the behaviour of many computers. The most advanced gaming PC has a processor (or several), an input in the form of a keyboard and mouse, an output in the form of a display and speakers, and vast memory to store the state of the game.

A digital alarm clock, which is also a computer, has an input (the user can set the alarm), outputs (the current time, and the alarm sound), processing (keeping track of what time it is), and memory (it needs to remember the time of the alarm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

CPU

A

The central processing unity executes program instructions, performing calculations and comparisons, as well as coordinating the behaviour of other hardware. The CPU comprises several different components

26
Q

Component and function of: The ALU

A

Performs various operations:

  • Arithmetic operations (+ - * /)
  • Relational operations (< > =)
  • Logic operations (AND, NOT, OR)
27
Q

Component and function of: Control Unit (CU)

A

Manages the execution of instructions by coordinating the activities of the other hardware

28
Q

Component and function of: Buses

A

Collections of wires that transmit data between computer components

Data bus - Moves data back and forth between the CPU and memory
Address Bus - Transmits memory locations. Any data retrieved from or placed into memory belongs in a specific address or memory location
Control Bus - Transmits commands to other components, such as READ (get data from memory) or WRITE (put data in memory)

29
Q

Component and function of: Registers

A

Short term storage for small, specific pieces of data, within the CPU itself. One register would store data just retrieved from memory; another would store the memory location from which that data came

30
Q

Component and function of: Clock

A

Every action performed by the CPU must begin during a clock pulse. A clock generates a pulse billions of times each second (in modern PCs), synchronising the activities within the CPU

31
Q

Main Memory

A

The main working area for data currently being used and programs currently running

32
Q

RAM

A

Random Access Memory
When a program is loaded from a computer’s hard disk, its data and instructions are loaded into RAM, which is generally much smaller but much faster than a hard disk. When a computer is turned off or subject to a loss of power, the content of RAM is lost. This means that RAM is volatile

If a computer has more RAM, it will be able to run more apps at the same time

33
Q

ROM

A

Read Only Memory
‘Read Only’ means that the content cannot be edited or deleted (meaning it is not volatile). As such, ROM stores data or instructions that will not need to be updated. ROM will typically store bootstrapping instructions, which tell the computer the initial steps in finding and initialising the operating system when the computer is turned on

34
Q

Cache memory

A

Cache memory stores copies of data or instructions from RAM that are accessed very regularly. This means that these data or instructions can be accessed very quickly, although a computer’s cache memory will usually be very small, measured in kilobytes or megabytes rather than gigabytes

35
Q

CPU performance

A

A CPU with a higher rate of performance can execute instructions more quickly than a CPU with a lower rate of performance.

36
Q

Factors affecting CPU performance

A
  • Number of cores
  • Clock Speed
  • Size of cache
  • Type of cache
37
Q

Core

A

A single unity, comprising an ALU and a Control Unity, which can execute instructions. Two cores can execute instructions at the same time, so more cores means more instructions per second that can be executed

38
Q

Multi-core processors

A

Four instructions with one core takes 4 instruction cycles
Four instructions with two cores (a dual core processor) takes 2 instruction cycles
Four instructions with 4 cores (a quad core processor) takes 1 instruction cycles

39
Q

Core speed

A

A dual core processor is not quite twice as fast as a single core processor, coz some time is typically lost to organising which core will follow which instruction (this time is called overhead). The overhead is however usually small enough that a dual core processor can be considered twice as fast as a single core processor with the same clock speed

40
Q

Clock speed

A

The number of clock pulses per second, typically measured in gigahertz (GHz). A 3GHz processor has a clock that pulses 3 billion times per sec, meaning there are 3 billion opportunities, each second, for an instruction to begin. Note that instructions might take longer than a single clock pulse to complete

41
Q

Cache Size

A

Cache memory is used to store data and instructions that will be accessed repeatedly. If more cache memory is available, a large amount of data and instructions can be stored there. Since cache memory is faster than any other form of memory, this would improve CPU performance

42
Q

Cache type

A

Cache memory can be L1 (level 1), L2, or L3. L1 cache is the smallest in terms of capacity, but it is also the quickest, as it can be found directly on the CPU. If the CPU needs a piece of data, it will first look in L1 cache. Failing that it will check L2 cache (which is larger but slightly slower), then L3 cache (larger but slower still), then main memory (larger and slower than L3 cache)

43
Q

To enhance CPU usage

A
  • Increase the number of cores
  • Increase clock speed
  • Increasing the size of cache memory
  • Maximising use of L1 cache
44
Q

Fetch execute cycle

A

A continual sequence of tasks that results in instructions being fetched from main memory, decoded so that the CPU knows what to do with them, then executes them, i.e. carries them out. This cycle happens many millions of times per second in a modern PC

45
Q

Fetch

A

1 - The clock pulses. The processor can only begin a task as the clock pulses, although a task may take more than one clock pulse to complete
2 - One of the registers contains the location (in memory) where the next instruction is to be found; this register is usually called the ‘program counter’
3 - This location, also called an ‘address’, is transmitted along the address bus to memory
4 - Memory responds by sending the content of that address along the data bus, back to the processor. In this case, an instruction is being transmitted, and it is stored in a register called the ‘Instruction Register’

46
Q

Decode

A

5 - The instruction is read by the control unit, which prepares the registers for whatever data they will be storing; the nature of this prep depends on what the instruction was

47
Q

Execute

A

6 - Here the instruction is carried out. It might be one of the following:

  • Retrieve a piece of data from memory and store it in a register
  • Perform some operation on data that is already in a register; if there is any kind of calculation or comparison, the ALU will carry out this part of the taks
  • Store something currently in a register, perhaps that has been processed in some way, in memory
  1. The program counter, which indicates the location of the next instruction, is updated coz the current instruction has been executed. Now the entire cycle begins again
48
Q

Secondary storage

A

Long-term storage in a computer system, necessary because main memory is volatile (loses its contents when powered down) and will also run out of storage space. Three types of backing store are optical, magnetic and solid state. All of these devices are required to store vast numbers of 1’s and 0’s, but they do so in diff ways

49
Q

Optical

A

Optical storage media (inc CDs, DVDs and BluRay disks) are written to and read from using lasers. Just like magnetic disks, optical disks spin to allow the laser to read the data from the correct location

The surface of the disks have billions of locations in which holes can be physically burned by a laser, or not burned, to represent either a ‘0’ or a ‘1’

50
Q

Optical adv and dis

A

Adv:

  • One optical disk is very cheap
  • Often read only, so difficult to accidentally overwrite data

Dis:

  • An unprotected disk is vulnerable to being scratched
  • Low data capacity
51
Q

Magnetic

A

Are round, although usually built into rectangular housing. The surface of such a disk is divided into tracks and sectors

Here there are 3 tracks that are circular in shape, each track divided into eight segments. The disk will spin to allow a read-write head to access the data in a particular segment. This will happen quickly with internal hard disks, which spin at 7,200 revolutions per minute (RPM). Within each sector, billions of magnetic particles exist that are either magnetised (1) or not (0)

52
Q

Magnetic adv and dis

A

Adv:

  • Cheapest storage medium per megabyte
  • Less cumbersome than multiple optical discs

Dis:

  • Slower access speeds than solid state
  • Unlike optical disks, data is all on one device, which can be lost
53
Q

Solid state

A

Use electronic circuits and no moving parts to store data electronically. No moving parts = sturdier and quieter than magnetic or optical devices. SSDs use electrical circuits which, unlike those of RAM, are non-volatile, meaning they retain data without a power supply

54
Q

Solid state adv and dis

A

Adv:

  • Faster access speeds than both optical and magnetic
  • No moving parts = harder to damage/break

Dis:

  • Most expensive form of storage per megabyte
  • Limited number of times each bit can be written to
55
Q

Cloud Storage

A

Involves storage on remote computers, usually managed by other organisations. When a file is saved or loaded, it is transmitted across the internet, and multiple backups of files often exist around the world. Cloud storage uses magnetic and increasingly, SSDs

56
Q

Cloud storage adv and dis

A

Adv:

  • With data stored remotely, and usually in multiple physical locations, it is less likely to be damaged by fire or misplaced
  • Capacity on your local machine is freed up, granting you more storage space

Dis:

  • Cloud storage comes with a subscription fee
  • The speed at which you can access your data is limited by your internet connection; it might take days to access a large video file
57
Q

Embedded systems

A

A computer that exists within a larger mechanical or electrical device such as a microwave oven or guided missile. Embedded systems are used when a whole computer is not viable (as in a microwave) or when they have only a single, specific purpose (as in a guided missile)

58
Q

Microcontroller

A

At the heart of an embedded system is a microcontroller, which is a chip that contains both storage and processing capabilities.
The microcontroller’s code usually runs in a loop, continually monitoring inputs, processing them and producing outputs. The processing power in such a device is usually considerably less than a modern PC, but these devices are much cheaper

59
Q

Embedded system examples

A
  • Automated teller machines (ATMs)
  • Printers
  • Utility smart meters
  • Petrol pumps
60
Q

Non-embedded system examples

A
  • Personal computers
  • Laptops
  • Tablets
  • Smartphones

When u restart the router (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions