113-input-and-output-and-storage Flashcards
1
Q
Input devices
A
- Peripherals that receives data from user/outside world
- Input can be manual e.g mouse or automated e.g sensor
- specialised devices: sip/puff switches, foot switches, Braille keyboards for disabilities
2
Q
Factors to consider when choosing a device
A
- accessibility
- accuracy
- speed
- compatibility
- cost
- purpose
- user preferences,
3
Q
Method for data inputs (Manual or automated)
A
- manual: flexible and adaptable, informed decisions, small data requiring human interpretation
- automated: less error-prone and expensive, done by device, faster and efficient esp for large amounts
4
Q
Output devices
A
- Peripherals that provides data to user/other devices
- convert digital data from a computer system into a format that humans can process (sound, images, vibrations)
5
Q
Storage Devices:
A
- medium that holds data and programs temp/perm
- internal examples: RAM, solid-state hard drive, magnetic hard drive.
- external examples: optical disk, USB drive, memory card, external hard drive.
6
Q
Choosing Secondary Storage Properties to Consider:
A
- Capacity and cost
- Read and write speed
- Portability: its size and weight and ability to be easily transported.
- Durability: withstand wear and tear overtime
- Robustness: withstand physical stress like impact or vibrations
- Compatibility: Is the device’s interface and own connectors compatible with the user’s system and connectors
- Reliability: to store data without corruption or loss.
- Longevity: how long the storage mechanism can be expected to function properly before failing
- Integrity: how trustworthy the data on a device is. if low integrity, it’s not reliable or accurate, can happen due to corruption, tampering, or errors.
7
Q
Storing data considerations
A
- Backing up important data
- Redundancy: creating duplicate copies of data on multiple disks or servers to protect against data loss in case of hardware failure.
- Encryption: protect against unauthorized access to sensitive data.
8
Q
Drive and Media
A
- drive: hardware device used to access/write data on a storage medium.
- media: physical object/material where the data is actually stored
- e.g hard disk drive (HDD) is a hardware device (drive) that reads and writes data to a magnetic storage medium (disk inside the hard drive where data is stored)
9
Q
Magnetic storage
A
- uses two magnetic state: magnetised (1) and demagnetised (0)
- data is stored on a platter (magnetic disk)
- read/write heads used while platter spins
- hard disk drives, portable HDDs, floppy disk drives, and tape drives
-backups, archives
10
Q
pros of Properties of Magnetic Storage
A
- High capacity 1-12TB: large quantity of data stored compactly
- cost-effective, very low cost per gb
- good reliability, lasts a long time
- not portable: moving parts but can be portable (portable hard disk drives/magnetic tapes) which are easily connected to devices
11
Q
cons of magnetic storage properties
A
- slow: moving parts (read/written sequentially, head moves through all preceding data)
- magnetic: particles on platter can demagnetise over time, causing data loss/corruption, or could get corrupted near a magnetic field.
- Moving parts so not durable(susceptible to wear n tear) and not robust (delicate and prone to damage from movement) can cause mechanical failure,data loss, or break during impacts/vibrations
12
Q
Optical Storag
A
- optical drive (uses a laser beam)
- optical media (store data using microscopic pits (0) and lands(1) e.g Blu-ray
- used for music, films, software, games and backing up data.
- laser burns indentation marks in spiral tracks into reflective disc surface.
- Laser light shone detects where marks are and translates it into readable format: if hits a land, reflected into a sensor, reflected elsewhere if hits pit
13
Q
pros of optical storage properties
A
- robust: waterproof and shockproof
- low cost per GB
- portable and has no moving parts
- be backed up easily.
- compatible with a wide range of devices, including computers.
14
Q
cons of optical storage properties
A
- parts in the drive have to move to find the right bit of data on the disk, slow access times and writing speed - but quicker to read than write.
- easily scratched and has low durability.
- small capacity (700 MB to 50 GB), each disk has a small capacity but multiple disks can be used to gain higher capacity of storage.
15
Q
Types of Optical Storage
A
- CDs - 720mb. Audio files, text, digital images.
- DVDs - stores games or standard definition movies for home viewing. 4.7-8.4 single disk gb. Digital videos.
- Blu-ray disks - high definition movies/games. 25-50 gb.
- Re-writable (RW) e.g CD-RW: can be written and read as many times, used for backups updated regularly
- Write-once (R) - written once by user, then cannot be overwritten, can be read many times. Used for copying data.
- ROM - data pre-written by manufacturer, cannot be overwritten. used for music, films, software, games.
16
Q
Flash Memory
A
- electrically erasable programmable read-only memory (EEPROM) used to create many flash memory devices:
- USB drives, SSDs, SD cards, ROM chips are made from EEPROM.
- Used in digital cameras, smartphones, and solid-state drives
- Flash memory is the underlying technology used in solid-state storage devices
17
Q
solid state storage
A
- Made of microchips with switches where 1 or 0 is stored, using silicon semiconductors forming logic gates NAND/NOR to store electrical charge
- Uses flash memory to store data so can be erased and reprogrammed electronically
- USB flash drives, solid state drives, memory cards, sd VARDS
18
Q
pros of Solid state storage properties
A
- Faster access times - no moving parts = durable + no waiting for parts to move when accessing data
- Robust - not easily damaged by shocks, suitable in industrial machinery and vehicles (exposed to lots of vibrations)
- large capacity (250GB-2TB),
- Highly portable and lightweight, used in smaller devices e.g smartphones and tablets.
19
Q
cons of solid state storage properties
A
- easily damaged by exposure to high temperatures/other environmental factors
- expensive
- Limited read-write cycles and lifetime - each time the memory is flashed, it wears down, lose access to drive once flash memory degraded past a point and becomes unreliable, leading to potential data loss + unusable
- Re-writable devices often include several blocks of flash memory, only one block must be flashed at a time and so the device will last longer.
20
Q
Types of solid state/flash memory storage
A
Secure Digital (SD) cards - SD cards are used to extend the capacity of devices such as: Cameras, Smartphones, Tablets - high capacity for their physical size. This is useful in these smaller devices.
Solid State Drives (SSD) - SSDs are often used in home computers because of their performance - form of re-writable flash storage.
21
Q
Primary Storage
A
- Memory that can be accessed directly by the processor
- Each memory location has a physical address used to locate and access its contents
- Used by the computer’s operating system to run the computer
- Stores code instructions to execute and files required by running programs
22
Q
RAM
A
- Volatile memory that holds programs currently in use, open applications, data in use, and the operating system
- Easily removed from the computer and upgraded/expandable/replaced
- Needs constant refreshing to stay active
- Contents change frequently
- Faster than secondary storage like hard disk drives (HDDs)
- ram is much more expensive per unit capacity than secondary storage media
23
Q
ROM
A
- stores boot up sequence for the bios which boots up computer, check the computer system for errors and loads operating system.
- Very small capacity
- hold the device drivers for interfacing with the input and output devices
- Embedded in the motherboard and usually not removed
- non-volatile and no need to refresh data as it is permanent
- Only interacts with the CPU under certain conditions
- Useful for storing fixed sequences of instructions, e.g. computer’s startup bootstrap routine
- Cannot be modified, useful for storing content distributions and storing instructions for embedded systems
24
Q
secondary storage
A
- Long-term, non-volatile storage used to permanently save files, data, and programs when computer is switched off and is not constantly connected to the computer.
- Provides larger storage capacity
- ROM cannot be written to, RAM is volatile and loses data when the computer is turned off. Necessary to back up data stored to prevent data loss.
- Not directly accessible by the CPU, unlike RAM and ROM.
- Includes SSDs and HDDs
- Some computer systems do not use secondary storage.
25
virtual storage (basically cloud storage although cloud storage typically refers to a specific type of virtual storage service provided by a third-party provider)
- abstraction from the user of multiple drives formatted to act as one single logical storage (data spread across multiple physical storage devices: harddrives, solid state drives, servers in cloud)
- files can be stored/retrieved in the same way as a physical drive but as remotely over the internet, can be accessed by any computer on the same system (cloud storage service/ networked storage e.g)
-OS/virtual storage software decides where to store the data based on factors(free space, access speed, redundancy requirements)
- Useful for organising network resources and cloud computing, files spread across a range of servers.
-same pros and cons as cloud storage
26
Logical storage
- Logical storage is the perceived storage area, while physical storage is the actual implementation and virtual storage is abstraction of logical storage from physical storage
- Example: a shared drive on a school network appears as a single storage area to students, but the folders and files may be stored across different media
27
Cloud Storage
- provides remote storage space for data accessible over the internet from anywhere.
- Data is stored on the internet and remotely in large centre data servers across the world and managed by cloud providers
- used for backup, disaster recovery, sharing files, and collaboration.
28
Cloud Storage Pros
- Cost-effective: eliminates need for on-premises/own storage infrastructure and maintenance costs.
- Scalability: storage capacity easily scaled up or down as needed, perception of unlimited storage.
- Easy Accessibility: data can be accessed from anywhere with an internet connection and allows for file sharing and collaboration.
- Automatic backups: most providers automatically back up data.
- Addition: Can be configured for hybrid setups, allowing for a mix of cloud and on-premises storage.
- Environmentally friendly: reduces e-waste and carbon emissions
29
Cloud Storage Cons
- Security: vulnerable to cyber-attacks and breaches.
- Reliability: reliant on internet connectivity, no access to files without internet connection, and third-party service providers.
- Privacy: raises concerns around data ownership and privacy.
- Speed: slow uploads and downloads, subject to bandwidth limitations. so may be slow access times with poor connectivity
- Compliance with data protection regulations (e.g. GDPR) is important when using cloud storage, as data may be stored in different countries with different laws.
- Cost: need to pay to upgrade storage capacity and sometimes its monthly
30
Cloud Computing vs Cloud Storage
- Cloud computing encompasses a broad range of services, including cloud storage, servers, databases and software over the internet on demand without physical infrastructure
Cloud storage is a specific type of cloud computing service focused solely on remote data storage.
31
Virtual Network
- software emulation of a network that allows you to connect devices and systems together even if they are geographically different
- provides an isolated and secure connection between them (traffic is kept separate)
- used cloud computing environments to connect servers and data centres together
-example is a VPN
32
Virtual Server
- software to emulate multiple instances of a server
- allows multiple virtual servers to run on a single physical server, with each virtual server having its own operating system, applications, and resources.
