3 Hardware Flashcards
What is the Internet of Things?
The connection of computer systems and everyday devices using the internet to allow data to be exchanged
What is a central processing unit (CPU)?
A component in a computer system that processes data and instructions
What is a microprocessor?
An integrated circuit that is able to perform many of the functions of a CPU, but on a more limited scale
What is an embedded system and what are examples?
A computer system designed to perform a specific function, like in a traffic light, a washing machine and a digital alarm clock
What is the fetch-decode-execute cycle and its main stages?
The cycle through which data and instructions are processed; fetch stage where instructions are fetched into CPU, decode stage where instructions decoded within CPU, execute stage where instructions executed by CPU
What is an architecture?
The design of a computer system, including the components it contains
What is an input device?
A device that allows data to be entered into a computer system
What is random access memory (RAM)?
A component in the CPU that holds data and programs currently in use
What is the hard drive?
A storage device that stores data permanently until it is deleted by the user
When the user wants to open a file stored on the hard drive, where will the data be brought?
Into RAM
What is a program counter (PC)?
A component in the CPU that stores the address of the next instruction to be processed
What is the address the program counter (PC) stores?
A memory location in RAM
What is the memory address register (MAR)?
A component in the CPU that holds the address of the data or instruction to be located in RAM
What is the address bus?
Wires used for the transmission of addresses between components in a computer
What is the memory data register (MDR)?
A component in the CPU that holds the data or instruction that is fetched from RAM
What is the data bus?
Wires used for the transmission of data and instructions between components in a computer
What is the current instruction register (CIR)?
A register built into the control unit (CU) that holds the current instruction being processed in the CPU
What is the control unit (CU)?
The component in the CPU that controls all the operations in the CPU, telling all components in the CPU when to perform their different roles
What specifically happens in the fetch stage?
Address sent from PC to MAR using address bus; MAR sends address to RAM location using address bus; data in location sent to MDR using data bus; MDR sends data to CIR using data bus
What happens in the decode stage of the fetch-decode-execute cycle?
The control unit (CU) decodes the instruction using an instruction set
What is an instruction set?
A set of commands that can be processed by a certain CPU
What happens in the execute stage of the fetch-decode-execute cycle?
If mathematical or logical calculations required for instructions to be executed, data used in process sent to ALU which performs all calculations, interim values stored in ACC, actions for instruction then performed after calculations performed
What is the arithmetic logic unit (ALU)?
The component in the CPU that performs all the mathematical and logical operations required when processing data and instructions
What is the accumulator (ACC)?
A register built into the arithmetic logic unit (ALU) that stores the result of any interim calculations
What is a control bus?
Wires used for the transmission of control signals between components in a computer
What does the CU use to send signals to all the components in the CPU?
The control bus
What are the main factors that can affect the performance of a CPU?
Number of cores, clock speed, size of the cache
What is a core?
The part of the CPU that contains all the components used to perform the fetch-decode-execute cycle
What is clock speed?
The number of cycles the CPU can perform per second (from internet, in book number of FDE cycles that can be performed per second)
What is a cache?
A type of data storage within the CPU which stores instructions and data the computer uses most, meaning the CPU doesn’t need to fetch it from RAM, just from the cache, which is quicker
What is an input device and examples?
A device that allows data to be entered into a computer system; examples are barcode scanners, digital cameras, keyboards, microphones, optical mouses, QR code scanners, scanners (2D and 3D), touch screens (resistive, capacitive and intra-red)
What is an output device and examples?
A device that can be used to obtain the results of data that has been processed; examples are inkjet printers, laser printers, light emitting diode (LED) screens, liquid crystal display (LCD) projectors, liquid crystal display (LCD) screens, speakers, 3D printers
What is a sensor and their features?
A type of input device that is used to capture analogue data from its immediate environment, normally at given time intervals
What is an automated system?
A system designed to operate without the need for any human intervention
What are the different types of sensors?
Acoustic, accelerometer, flow, gas, humidity, infra-red, level, light, magnetic field, moisture, pH, pressure, proximity, temperature
What does an acoustic sensor do?
Measures level of sound in an envrionment
What does an accelerometer do?
Measures acceleration forces, which can be static forces like gravity or dynamic forces like those created by movement and vibrations
What does a flow sensor do?
Measures the amount of liquid, gas or steam flowing through or around a certain environment
What does a gas sensor do?
Measures the presence and concentration of a gas within the immediate atmosphere
What does a humidity sensor do?
Measures the level of moisture in the immediate atmosphere
What does an infra-red sensor do?
Measures infra-red radiation, which can be emitted in different amounts by both objects and people
What does a level sensor do?
Measures whether a substance, such as a liquid, is at a certain level or amount
What does a light sensor do?
Measures the ambient light in a certain environment, can also measure the present of a direct light, such as a laser beam
What does a magnetic field sensor do?
Measures the presence of magnetic field that may be emitted by an object
What does a moisture sensor do?
Measures the amount of water present in a substance, such as soil
What does a pH sensor do?
Measures the pH level of a substance
What does a pressure sensor do?
Measures the force of pressure applied to the sensor or device, could be the pressure created by a solid object, or the pressure created by liquid or gas
What does a proximity sensor do?
Measures how close an object is in comparison to the sensor, does this by emitting electromagnetic radiation or an electromagnetic field and measures radiation as it returns to see if there are any changes
What does a temperature sensor do?
Measures the temperature of an object or substance by either directly touching it or capturing data from the surrounding environment
What are the 2 main categories of storage that exist in a computer?
Primary storage, secondary storage
What is primary storage?
A type of storage that is directly accessed by the CPU
What are the main types of primary storage?
Random access memory (RAM), read only memory (ROM)
What is random access memory (RAM) and its properties?
A type of primary storage which is volatile, stores data and programs currently used by computer, contents constantly being changed, possible to increase amount of RAM
What is read only memory (ROM) and its properties?
A type of primary storage that stores the start-up instruction for the computer, it is non-volatile, it stores programs that initially boot the computer (like bootstrap and the BIOS), contents of ROM fixed and don’t normally change, not easy to alter ROM available in a computer system
What is secondary storage?
A category of non-volatile storage not directly accessed by the CPU that is designed to store data permanently until it is deleted by the user
What are the main types of secondary storage?
Magnetic storage, optical storage, solid-state storage
What is magnetic storage?
A type of secondary storage that uses the properties of magnetism to store data, modern magnetic storage device normally has circular plates called platters, separated into tracks and sectors, that spin
How is data represented in magnetic storage?
Electromagnet used to magnetise dots on platter, magnetised dot stores binary value 1, demagnetised dot stores binary value 0
When was the first hard disk drive sold, by who, and how good was it for its price?
In 1956, technology company called IBM sold first hard disk drive with storage capacity of just 5 MiB and cost $50,000
What is optical storage?
A type of secondary storage that uses lasers to store data
What are types of magnetic storage?
Hard disk drive, magnetic tape, floppy disks
What are examples of optical media?
CD, DVD, a Blu-ray
What is solid-state storage?
A type of secondary storage that uses transistors to store data
What is a semiconductor chip?
An electronic circuit where transistors are set on a semiconductor material such as silicon
What are the details of solid-state storage?
Doesn’t have any moving parts, created using semiconductor chips, contains cells and transistors laid out in a grid, one of the transistors is called a control gate, one of the transistors is called a floating gate, all transistors set to binary value 1 upon device creation, when data stored, converted to binary value 0
What are examples of solid-state storage?
Solid-state drive, USB flash memory drive (also known as USB stick)
What is a cell?
Intersection of rows and columns of transistors in solid-state storage
What is a transistor?
A device that acts as a switch or date for electronic signals
What is a control gate?
A component that controls the flow of electric current
What is a floating gate?
A component that can store electrical charge
What is virtual memory?
A type of memory that can be used as an extension to the RAM
How is virtual memory used?
When RAM gets full, the computer system transfers data to virtual memory not as immediately needed as other data and collects it in page, once pages needed again, they are sent back to RAM to be processed
What is a page?
A unit of data
What is cloud storage?
Data storage that is owned by a third party and accessed by the user, using the internet
What is a server?
A component that acts as a central resource for the storage of data and applications or for providing a service
What is storing data locally and storing data remotely?
Storing data locally is when data is stored in buildings and hardware owned by individual or business, storing data remotely is when data is stored in hardware owned by a third party and accessed using the internet
What are the details of storing data in the cloud?
You don’t have to pay for the hardware; you don’t have responsibility for security of hardware that stores data, you rely on third party to keep your data safe; you can access the data using devices from anywhere you have internet connection; you can increase and decrease amount of storage space easily
What are the details of storing data locally?
You need to buy the hardware; you need to make sure your data storage is well-maintained and secure; you can access your data at all times you have local access to it; you might have redundant hardware you paid for as the amount of data you need to store has decreased
What is a network?
Computers and devices that are joined together using cables or wireless technology
What is a network interface card and its types?
The component in a computer that is used to connect it to a network, with wires NICs and wireless NICs (WNICs)
What are transmission media?
The cables used to transfer data in a network
What is a media access control (MAC) address?
The unique address that is given to a network interface card (NIC) by the manufacturer
What is the structure of a MAC address?
6 pairs of numbers in hexadecimal, separated with either a dash or a colon
What different structures can an IP address have?
IPv4 or IPv6 structure
When was IPv4 created and how many bits does it use to create each numerical IP address?
Created back in 1983, uses 32-bits to create each numerical IP address
How many bits does IPv6 use to create an IP address?
128 bits
What are the differences between a static and dynamic IP address?
A static IP address does not change each time the device connects to a network, a dynamic IP address can change each time the device connects to a network
Who normally provides you with a static IP address for your device?
Your Internet Service Provider
