What is the CPU?
Central Processing Unit. It is the main component in a computer for processing data and instructions.
What happens in the CPU?
All the data is read and acted upon.
What is RAM?
Random access memory.
What is RAM used for?
Ram is where all the data for a program is stored. The bigger the ram the faster big programs load.
What is the purpose of the motherboard?
The motherboard is what holds all the hardware together. Also moves data around.
What does the data bus do?
A data bus is the path along which data travels to be moved between parts of a computer
What does the address bus do?
It is where the address of the place (in memory) where data is to be saved or loaded from is sent
What does ALU stand for?
Arithmetic and Logic Unit.
What does the ALU do?
The ALU performs all mathematical calculations and logical operations on the CPU. It performs simple mathematical calculations on data that is stored in the registers temporarily, and can also do comparisons between data (Logical operations)
What does the controller in the cpu do?
The controller sends and receives signals from all parts of the computer, ensuring all processes take place at the right time and in the correct order
What is a register?
A register is a storage location found on the cpu (volatile) where data or control information is temporarily stored.
What is Internal Memory?
Internal memory is fast access temporary (volatile) storage on the CPU.
Where can data from internal memory be written pn or called back to?
It can be written to the RAM or called back to the registers for further processing.
What is the control bus?
The controller uses the control bus to send control signals to different parts of the computer.
What is the basis for the fetch-decode-execute cycle?
Von Neumann Architecture is the basis for the cycle.
What happens during the ‘fetch’ process of the fetch-decode-execute cycle?
The processor checks the program counter to see which instruction to run next
It indicates the address value in memory where the instruction is.
The processor fetches the instruction from the memory location and stores it in the registers
It then moves the program counter on one so that it points towards the next instruction.
What happens during the ‘decode’ part of the fetch-decode-execute cycle?
The control unit checks the instruction in the instruction register and decides it to determine what action is to be carried out.
What happens during the ‘execute’ part of the fetch-decode-execute cycle?
The actions that have been determined in the decode part actually happen
What is the ‘cache memory’ in the CPU?
Cache memory is a fast access type of memory
What is ‘clock speed’?
Clock speed is the, speed at which a processor operates. The faster the clock speed, the faster the computer is able to run the fetch-decode-execute cycle.
What is clock speed measured in?
The clock speed of a processor is measured in Hertz (Hz). One clock tick per second would be measured as 1 Hz. Therefore a processor running at 1000 clock ticks per second would be a 1000Hz or 1kHz processor.
What is Overclocking?
When a processor is set to run faster than its original design by increasing the clock speed
What is underclocking?
When you lower the CPU’s clock speed. Set to run lower than the original design
How does the number of cores in a CPU affect the computer?
Each core can run one instruction at a time. More cores means that more instructions can be run at a time making the cpu faster
What are the two types of processors?
Reduced Instruction Set Computer (RISC)
Complex Instruction Set Computer (CISC)
What is ROM used for?
ROM is used for the permanent storage of data. The data in each store location cannot be changed. Read Only Memory, not write.
What is flash memory used for?
Flash memory is used for the permanent storage of data. However, the data stored in flash memory can be changed.
What is RAM used for?
RAM is used to store the currently running program.
When is data written to secondary storage? What is the disadvantage?
Data is written from memory to secondary storage when data is no longer being actively used, for retrieval at a later time. However the time the computer takes to access data stored on secondary storage is longer than accessing it from memory
Define ‘data capacity’
Data capacity is the amount of data a storage device can hold measured in Kilobytes (Kb), Megabytes (MB), Gigabytes (GB) Terabytes (TB).
List the properties of a ‘flash drive’
- Capacity: 2GB to 64GB
- Very fast
- Very portable
List the properties of an ‘external hard drive’
- Capacity: 500MB to 4TB
- not very durable
List the properties of a ‘cd/dvd/blue-ray disc’
• CD 650 MB
•DVD 9 GB
• Blue-ray 50 GB
- ok speed (you have to burn data to the disc)
How many bits are in a byte?
8 bits in a byte
How does cloud storage work?
Storage in the cloud is a contemporary data storage facility that allows users to store their data on third-party servers. They can then access that data from many computing devices.
What is the motherboard?
The motherboard is the main circuit board of a computer.
What is a GPU (graphical processor unit or graphics card)?
A GPU is a microprocessor that performs the calculations needed to produce graphic images
What does an integrated GPU use for memory?
An integrated GPU uses the computer’s RAM.
What as a dedicated GPU? What is it’s advantages and disadvantages?
A dedicated GPU has its own video memory. Dedicated cards provide the best visual
experience and are used by people such as professional graphic designers and serious
gamers, but they use more power and require a good cooling system.
What are sound cards?
Sound cards enable the computer to output sound through speakers, to record sound from a microphone and to manipulate sound stored on a disk.
Sound cards convert analogue input signals into digital data and reverse this process for audio output.
What are embedded systems?
An embedded system is a combination of software and hardware that performs a specific
task rather than a general-purpose computer that is designed to carry out multiple tasks.
Embedded systems are included as a part of a complete device often with hardware and
mechanical parts. As the systems carry out specific tasks they can be designed to be small
and have a low cost. Mass-production of embedded systems can save large amounts of
Give some examples of devices that use embedded systems:
Electronics Mobile phones, games consoles, printers, televisions, digital
In the home Washing machines, microwave ovens, refrigerators,
dishwashers, air conditioners
Medical equipment CT Scanners, Electrocardiogram (ECG), MRI Scanners, blood
pressure monitors, heartbeat monitors
Cars Electronic fuel injection systems, anti-lock braking systems,
What is CPU architecture?
A term that refers to the design of a microprocessor where the components of the cpu are combined as a single unit
How do we store zeros and ones inside of a computer?
What are transistors? Where are they located?
Microscopic switches that control the flow of electricity depending on if they are on or off. They are located on a very thin slice of silicon.
What sub components is the CPU made up of?
Controller, ALU, registers, internal memory
What is an accumulator?
It is the register used by the ALU to store the results of its calculations
Summarise the controller
- Manages the execution of instructions
Summarise the ALU
- Processes and manipulates data
- Fast access temporary data stores
Summarise internal memory
- Fast access memory in the CPU
What do buses allow?
They allow data to be transferred to different parts of the computer
What did John Von Neumann propose?
Storing program instructions in the same memory as the data
A stored program
What did Von Neumann architecture result in? What is it the basis of?
Computers that could be more easily re-programmed. It is the basis for the fetch-decode-execute cycle
How many Hz in a GHz?
What do RISK processors do with complex instructions?
To carry out complex commands RISK processors break up the program into a longer list of simpler instructions
What are the advantages of RISK processors?
Risk processors can process simple instructions very quickly and require less circuitry for processing simpler instructions meaning less power and heat
What is the advantage of cisk processors?
They can process a large number of complex instructions without having to break them down into simpler instructions. They can carry out complex tasks with only a few instructions
What are the drawbacks of cisk processors?
They require more circuitry to decode and execute complex instructions meaning more heat and power consumption
Ram is volatile, what does this mean?
Data is lost when power is turned off
What is RAM used for?
RAM is used for the temporary storage of currently running programs and data.
What does ram consist of?
It consists of a large number of store locations each defined by a unique address
How do optical storage devices work?
They use technology such as lasers. Disks have a reflective surface which when written into by a laser is burnt for a 0 and not for a 1. When reading a non burning laser is shine at the disk. Non burnt surfaces will reflect it back to be read as 1 but burnt ones will not as 0
How does magnetic storage work?
Data is written and read by a read/write head. The read head stores data by changing the magnetism of parts of the disk to face up or down as 1 or 0. The read head detects the magnetism to read it as 1 or 0
What are transistors?
Switches that controll the flow of electricity depending on if they are on or off.
What is used to store data in the CPU?
What are the parts of a CPU?
Controller, ALU, registers, internal memory
Why are registers useful?
They are much faster to access than internal memory
When is data moved to the internal memory?
From the registers when the data is not being actively used
What can be done with data on the internal memory?
It can be either written to ram or back to the registers for further processing
What does the control bus do?
It is used by the controller to send signals to different parts of the computer
How are buses used to save/load data?
First the address of where to save/load is sent on the address bus, then the data on the data bus. And the controller sends the read/write signal on the control bus
What did von Newman propose?
Storing program instructions on the same memory as data
What is the advantage of von Newman architecture?
Computers could be easily re-programmed as the program is stored
In brief summary what happens during the fetch-decode-execute cycle?
1) address required taken from memory, stored in register, program moves to next instruction
2) control unit determines what the instruction is asking
3) The instruction is executed
What does the cache memory do for the CPU?
It is able to provide instructions much faster than ram or other memory improving CPU performance
What are the prefixes for 10^3,6,9
Kilo, mega, giga
When wis under-clocking useful?
It results in a lower power consumption so longer battery life for mobiles
What is the downside of overclocking?
If heat is not removed trough cooling, the CPU can overheat shortening it’s lifespan and damaging it
What is a ‘core’?
The procesisng components within the CPU
Why do two cores not necessarily double processing speed?
Sometimes instruction 2 may need the result from a previous instruction 1 being run on the other core
How can a RISC processor process instructions and what is the advanatage?
They can process a limited number of simpler instructions and complex ones are broken down into a longer list of simple ones. This allows them to perform many simple instructions fast and produce less heat using less power as less circuitry
How can a CISC processor process instructions?
It can process complex instructions, so it can perform complex tasks with only a few instructions
What is the advantage and disadvantage of CISC processor
It can perform complex instructions without breaking them up but needs more circuitry so uses more power and produces more heat
What is the structurre of RAM like?
It has a large number of store locations each identified by a unique address. Data can be written and read but is volatile
What is the BIOS?
A low-level program that handles input and output operations. It provides an interface between hardware and the operating system
What is the bootstrap loader and where is it executed from?
It is the program that loads the operating system run from the BIOS
What is Cache memory used for?
It is used for the temporary storage of frequently accessed data and instructions
What is the advantage of Cache memory?
It can be accessed very quickly by the cpu
List the properties of a magnetic tape?
- ok durability
What would you use a flash drive for?
Moving relatively small files from work to home
What would you use an external hard drive for?
Backing up a home computer system
What would you use a CD/DVD for?
Storing multimedia files
What would you use a magnetic tape for?
Backing large commercial servers on multiple tapes
How does optical storage work?
Lasers are projected onto a CD/DVD. If light is reflected back it is read as a 1, if it is not it is a 0. A burning laser is used to write to the disk
How does magnetic storage work?
Data is stored on magnetic medium such as a disk or tape. It is written by the write part of a read write head and read by the read part
Where would solid state technology be used and why?
In storage media such as pas USB flash memory. It has low power consumption and high access speeds
What are some advantages of cloud storage?
- Data backup and replication
- Data mantainance tasks
- access anywhere
What are some disadvantages of cloud storage?
- An internet connection is required to access data
- privacy concerns
- Storage reliability
What is a BIT?
A 1 or 0
What are some advantages of an integrated GPU and what is it good for?
An - cheaper than installing a
- it generates less heat and uses less power.
They are perfect for general
graphics processing such as watching or editing videos and word processing.
What is the difference between an integrated GPU and a dedicated one?
An integrated GPU uses the computer’s RAM whereas a dedicated one has it’s own video memory
What is an advantage but a disadvantage if a dedicated GPU?
It provides the best visual experience and does not eat into the computer’s RAM but it uses more power so requires a good cooling system
What is an embedded system?
An embedded system is a combination of software and hardware that performs a specific task, unlike a general-purpose computer designed to carry out multiple tasks
Where are embedded systems used?
They are included as a part of a complete device often with hardware and mechanical parts.
Give some examples of devices that use embedded systems?
Mobile phones, games consoles, printers
MRI scanners, pressure monitors
Anti-lock breaking systems
Why would you use an embedded system? (Advantages)
As the system carries out specific tasks they can be designed small and with a low cost. Mass production of them can save lots of money.
What is firmware?
The software written for an embedded system.
Firmware software is stored in ___ or Flash memory, runs with limited computer hardware resources and ___
Read only memory, memory
Most embedded systems are reactive, what does this mean?
They react to conditions such as weight, temp, pressure etc. They detect external conditions and react to them
What must reactive embedded systems be?
Completely reliable, probably fast