U2: Fundamentals of Computer Science Flashcards
What is Hardware?
The physical components of a computer system.
Give some examples of hardware.
▪ Screens ▪ Keyboards ▪ Mice ▪ Printers ▪ Cabling ▪ Mobile devices ▪ Servers
What is an MFD?
Multi-functional devices are those that perform multiple functions.
Give examples of MFDs.
▪ Printers - often combine the functions: printing, scanning, faxing and photocopying
▪ Smartphones - combine the functions of a: phone, camera, computer, touchscreen, etc.
What are PCs?
A personal computer is a general-purpose computing device that is small and cheap enough to be used by individuals. The term personal computer usually refers to desktops and laptops.
What is a general-purpose computer?
Devices capable of performing the most common computing tasks.
What are the professional uses of PCs?
They are used for anything useful to the organization, which normally requires the use of software programs such as word processors, spreadsheets, databases, programming environments, and other software applications.
What are the features of Desktop PCs?
▪ Not portable so are usually left in one place.
▪ Cabled connection to a network.
What are the features of Laptop PCs?
▪ Portable
▪ Moved within a wireless, WIFI network.
▪ Uses for individuals who want flexibility
What is the motherboard and what does it do?
The motherboard is the main circuit board that connects the attached components and allows them to communicate with one another. These components include; the CPU, RAM, Secondary storage and external components such as; the keyboard, mouse, monitor, printer, network.
What is the CPU?
The central processing unit (CPU) is a chip that plugs into a compatible socket in the motherboard. This components processes code, by working out any calculations, logical operations or relational comparisons.
What is RAM?
Random access memory (RAM) stores files and software that is in use.
What type of RAM is used in PCs?
DDR RAM
What is secondary storage and how is it connected to the motherboard in a PC?
Secondary storage is where files and software are stored when they are not in use. It is connected to the motherboard via a cable.
What storage types are used in secondary storage for PCs?
The most commonly used type of storage is HDD. However, SSD storage is becoming more popular.
What are expansion slots for in a PC?
Expansion slots are used to connect expansion cards, such as graphics cards to the motherboard.
What is an expansion card?
Expansion cards are cards that allow the user to add additional, specialist capabilities to the PC.
What are graphics cards and what are they used for?
Graphics cards contain a GPU and VRAM, used to perform tasks involved in rendering graphics. They are used for rendering video games and for aiding in the production of digital art.
What are Mobile devices?
Mobile devices are MFDs that can consist of a computer, camera and, in some cases, phones.
What are the main features of mobile devices?
▪ Compact
▪ Light-weight
▪ Long battery life
▪ Wireless connection to the internet
Give some examples of Mobile Devices.
▪ Smartphones
▪ Smartwatches
▪ Tablets
▪ Mobile Phone
Modern Mobile devices
Recently there has been a lot of development in mobile devices and recent mobile devices are almost as powerful as PCs, have good internet connection and a long battery life.
What is the name of the integrated circuit which holds the main internal components of a mobile device?
System-on-a-Chip
What is the SoC?
The SoC is a circuit that holds a mobile devices CPU, GPU, Storage, Memory and other important components.
What are the disadvantages of the SoC?
▪ No parts are replaceable
▪ no individual components can be upgraded
What are the advantages of the SoC?
▪ Saves space and allows the device to be smaller
▪ the size allows a larger battery to be used
▪ Efficient
▪ Produces less heat so a fan is not needed.
▪ Reduces power consumption
What type of memory and storage does the SoC use?
▪ LPDDR RAM - uses less power than normal DDR RAM.
▪ Flash memory as storage - less power consumption.
What CPU architecture does the SoC use?
ARM Architecture.
What advantage do desktop PC components have over mobile and laptop PC components?
Desktop PC components are removable, so they can be replaced and upgraded when necessary or when the user desires to.
What is a server?
Servers are computers that run a network operating system, and allow users access by login on workstations (or client computers).
Give some examples of types of servers and what they do.
▪ Web servers: Hosts web pages & associated files
▪ Mail Servers: Sends & Receives emails
▪ File Servers: Stores & manages users access to files & folders on a network
▪ Print Servers: Manages & provides access to printers on a network
What is the difference between PC and Server CPUs?
Server CPUs have :
▪ More cache
▪ (sometimes) more cores, which they can make more efficient use of.
What do severs use for main memory?
DDR RAM and, more likely also, ECC.
What is ECC?
Error correcting code: designed to correct error that might appear in volatile memory.
Why is ECC used in servers used in servers and not PCs?
The volatile memory in servers in often considered to be more important.
What type of storage do servers use?
Mainly HDD due to the large storage requirements but SSD can be used for boot drives.
However, the HDD storage in servers in not the same as that used in PCs.
Why do server HDDs have to be different to PC HDDs?
Normal HDDs have moving parts, when they are tacked in servers this causes a large amount of vibration. This can lead to dgamage so server HDDs are made with more protection.
What type of GPU do servers usually have?
Servers don’t usually have any graphics card or integrated GPU in the motherboard as servers are not usually used for graphically intensive tasks.
What are the main features of server internal components?
▪ expensive for similar speed & capacity
▪ Greater quality checks
▪ Better error prevention
▪ Greater energy efficiency
What type of GPU do servers usually have?
Servers don’t usually have any graphics card or integrated GPU in the motherboard as servers are not usually used for graphically intensive tasks.
What are the main features of server internal components?
▪ expensive for similar speed & capacity
▪ Greater quality checks
▪ Better error prevention
▪ Greater energy efficiency
What is the CPU?
The CPU is a processor that executes instructions, logical and arithmetic operations.
What are the main factors that affect CPU performance?
▪ Number of Cores
▪ Clock Speed
▪ Cache Size
What is the Number of Cores and how does it affect CPU performance?
How many instructions can be processed simultaneously. A higher number will increase performance as processing speed increases.
What is the Clock Speed and how does it affect CPU performance?
How many cycles can be executed per second or instructions per second. 1GHz = 1 billion instructions per second. High clock speed improves execution speed.
What is the Cache size and how does it affect CPU performance?
Cache is high speed memory that stores frequently used data and instructions for the CPU to process.
What other feature must be considered when choosing a CPU?
Sockets. The sockets in the motherboard must match the CPU.
What is main memory in a computer?
RAM
Is RAM volatile? What does it mean?
RAM is volatile memory.
This means that when the computer is turned off, the contents are deleted
What factors affect the performance of RAM and which is the list important?
▪ Memory Size - most important
▪ Memory Speed
▪ Compatability with motherboard
How does memory size affect the performance of RAM?
All active files and software is copied into RAM which requires a large amount of memory. If RAM isnt large enough, virtual memory will be used which is alot slower, so the devices performance would be slower.
How does memory speed affect the performance of RAM?
RAM speed is a combination of clock speed (cycles per second) and timings (number of cycles need to perform a task).
Higher RAM speed will produce a better performing system.
How does compatability affect the performance of RAM?
If a motherboard has slots for DDR4 RAM but you want to implement DDR3, the system will not be able to function.
What are the two major components contained within a graphics card?
▪ GPU (Graphics processing unit)
▪ VRAM (Video RAM)
What is the advantage of installing a graphics card?
The GPU & VRAM reduce the load on the CPU and RAM. They are also specialised to perform graphics processing more efficiently than the CPU.
What factors affect the performance of graphics cards?
► GPU Cores/Clock Speed: GPUs have thousands of cores as graphics processing involves performing many similar operations simultaneously. Clock speed will be slower than that of the CPU, but it us still important for performance.
► VRAM Size/Clock Speed: VRAM is used to store data the GPU will need to render images, such as textures & the frame buffer. It will often be a similar size to RAM but it will be specialised for graphics processing tasks and tends to have a higher clock speed.
How is the graphic card connected to the motherboard?
Graphics cards are connected using a PCI Express expansion slot.
There are different types of PCI Express slots, but they are backwards compatible, so you’ll still be able to connect your modern graphics card in an older slot (albeit with a hit on performance).
What is an input device?
A device that allows users to enter information into the computer. This can be as data or instructions.
Give some examples of input devices:
▪ Keyboard ▪ Mouse ▪ Microphone ▪ Webcam ▪ Scanner ▪ Graphics tablet ▪ Sensor
How do keyboards allow user input?
Keyboards have keys that allow users to input data or instructions.
What affects the performance of keyboards?
▪ Sensitivity - more expensive gaming keyboards use mechanical keys, rather than a membrane, which allows for greater sensitivity to touch. They’re also more durable to extensive use.
How do mice allow user input?
Mice are pointing devices that allow the user to select options from the GUI.
What affects the performance of mice?
▪ Sensitivity (measured in dots per inch (DPI)). A higher DPI will detect smaller movements and many expensive mice will allow you to alter the DPI for different situations.
How do microphones allow user input?
Microphones allow sound transmission over the internet. They also allow users to give voice commands to the computer/device.
What affects the performance of microphones?
▪ Sound quality - This is mostly measured by the sample rate and bit depth of the microphone.
How do webcams allow user input?
Webcams are video cameras that allow the transmission of moving images through an internet connection. This can be combined with microphones to allow users to communicate with another.
What affects the performance of webcams?
▪ Resolution
▪ Colour depth - how many colours can be represented
How do scanners allow user input?
Scanners allow physical documents to be converted into digital data so that they can be viewed and edited on a computer. This is done by shining light on the document which reflects onto a CCD array.
What affects the performance of Scanners?
▪ Resolution
▪ Colour Depth
How do graphics tablets allow user input?
The stylus is used to enter data. It is commonly used to produce illustrations.
What affects the performance of graphics tablets?
▪ Resolution
▪ Pressure Sensitivity - this allows a greater range of pressure to be detected from light to heavy touch.
How do Sensors allow input?
Sensor take environmental readings such as temperature, light and motion.
What affects the performance of sensors?
the factors that affect the performance of sensors depends on the type of sensor.
What is an output device?
A device that sends data from a digital device to a user or other device.
Give some examples of output devices:
▪ Monitor
▪ Printer
▪ Speakers
▪ Actuator
How do monitors allow output?
Monitors produce a visual display of a GUI.
What affects the performance of monitors?
▪ Resolution
▪ Refresh Rate
What is Resolution?
The Number of Pixels that make up an image.
What is refresh rate?
Number of images per second
How do printers allow outputs?
Printers produce physical copies of images and documents.
What affects the performance of printers?
▪ Print Speed
▪ Horizontal Resolution
How do speakers allow outputs?
Printers produce audio output by converting digital audio signals from a computer into analogue signals. They are often used to listen to music.
What affects the performance of speakers?
▪ Output wattage - has a big impact on volume.
How do actuators allow output?
They control and produce motion, usually in sensors.
What affect the performance of actuators?
▪ Torque - The amount of force it can produce.
What units are used to measure resolution?
Lines per inch
What units are used to measure refresh rate?
Hertz
What is an input/output device?
A device that can produce both inputs and outputs.
Give some examples of input//output devices:
▪ USB
▪ Joystick
How do USBs allow both inputs and outputs?
USBs can be used for input devices such as keyboards & mice, but they can also be used for output devices such as printers, flash drivers & external hard disks.
How do joysticks allow both inputs and outputs?
Thy are generally input devices that allow users to control an aspect of a video game. However, some of these devices also produce haptic feedback.
What is haptic feedback?
Haptic feedback is a type of output. It is a tactile sensation that users feel in their hands in response to something happening in the software.
What type of storage are HDDs used for?
▪ Primary Storage
▪ External portable Storage
How do HDDs work?
HDDs area form of magnetic storage. It consists of a number of magnetic plates that become magnetised or demagnetised in certain places to represent (1s or 0s) the data.
What are the advantages of using HDDs?
▪ High capacity for a low cost
▪ Reliable - with long life span
What are the disadvantages of HDDs?
▪ Slow read/rite speeds
▪ Contain moving parts - this is risky in portable devices
▪ Large compared to SSDs - cant be used in laptops or mobile devices.
What type of storage are SSDs used for?
▪ Primary Storage
▪ Flash Memory
How do SSDs work?
They store data using semiconductor chips. The chips can be turned on and off, 1 being on and 0 being off.
What are the advantages of SSDs?
▪ Fast read/write speeds
▪ Low power consumption
▪ No moving parts - reliable even when used as portable devices
What are the disadvantages of SSDs?
▪ Expensive, compared to HDDs, for the same amount of storage.
▪ Finite number of writes
What are the other forms of flash memory?
▪ SD cards
▪ USB flash drives
Designed as portable devices (Light-weight, Small)
Give some examples of optical disk drive devices and their uses:
▪ CD - Music
▪ DVD & Blu-Ray - films, tv, software
How do optical disk drives work?
A laser marks the disk in a pattern which is read by sending light to bounce off the disk. This light is then read back differently depending on weather it hit a pit or a land.
Pit - Marked area (binary 0)
Land - Un-Marked area (binary 1)
What are the advantages of optical disk drives?
▪ Cheap
▪ Small
▪ Portable
What are the disadvantages of optical disk drives?
▪ Small capacity
▪ Easily damaged
▪ Finite number of writes.
What is RAID?
Redundant Array of Independent Disks is a technology used to store data in multiple locations across separate disks. It has redundancy to protect data nd improve performance.