Computers & Components (Cambridge (CIE) A Level Computer Science): Flashcards

Magnetic, which magnetises particles on a disk or tape; optical, which uses a laser to burn pits into a disc surface; and solid state, which stores data in flash memory cells.

It offers high capacity and a relatively low cost per gigabyte, but has slower read/write speeds, is susceptible to physical damage, and its moving parts wear out.

It offers fast read/write speeds, no moving parts so less failure from physical shock, and silent operation, but has a higher cost per gigabyte and its cells wear out after a number of write cycles.

False.

Optical storage has a lower storage capacity than the other types and slower read/write speeds; its strengths are durability against environmental conditions and being easy to transport.

An embedded system is a computer system used to perform a dedicated function inside a larger mechanical unit.

Heating thermostats, hospital equipment, washing machines, dishwashers, coffee machines, satellite navigation systems, factory equipment, security systems and traffic lights.

It is small and compact, has low power consumption, is fast and reliable for repetitive tasks, is cheaper to produce using minimal hardware, and works in real-time.

It has limited functionality, is hard to upgrade or repair since it is built into the device, has limited memory and processing power, is not flexible, and may be less secure.

An embedded system performs a dedicated function inside a larger mechanical unit.

Because it works in real-time, and is fast and reliable for quick, repetitive tasks.

Because it uses minimal hardware.

It is often built into the device, and it is not flexible so cannot easily be reprogrammed for other tasks.

It is built into the car, it only performs one task, and it is not easily changed or updated by the car owner.

It has limited protection if connected to other systems.

False.

An embedded system is not flexible and cannot easily be reprogrammed for other tasks.

It converts sound waves into electrical signals.

Dynamic microphones are good for loud environments, while condenser microphones are more sensitive and accurate and are used in studios.

Capacitive responds to the electrical charge from your finger, while resistive responds to pressure.

A laser beam draws the image of the page onto a photosensitive drum, changing its electric charge, and toner is transferred from the drum to the paper.

The paper passes through hot rollers, which melt the toner onto the paper so it does not smudge.

It builds objects layer by layer from the bottom up, using materials such as thermoplastics, resins and metals.

FDM melts plastic and builds in layers, while SLA uses light to harden liquid resin.

It converts electrical signals into sound waves.

Head tracking, motion sensors and stereoscopic displays for 3D vision.

Expensive hardware, possible eye strain or motion sickness, and time-intensive content creation.

It has one or more platters whose surfaces can be magnetised, divided into concentric tracks; the disks rotate at high speed, and each surface has a read/write head mounted on an arm just above it.

The read/write arm of a hard disk is controlled by an actuator, which positions the head over the correct track sector.

Into concentric tracks and wedge-shaped sectors, which together form track sectors.

It stores data in cells using transistors that act as switches, using NAND or NOR gates to control the flow of electrons.

Writing uses a high voltage to push electrons onto the floating gate; erasing reverses the high voltage to pull electrons off it.

False.

A laser scans the surface, and changes in reflection from the pits and lands indicate 0s and 1s.

A buffer is a temporary storage area that holds data while it is being transferred between two devices or processes.

They help manage speed differences between components, ensuring smooth data flow.

Data is collected in the buffer before being processed or output, and when the receiving device is ready it takes data from the buffer.

It stores keystrokes until the processor is ready to handle them.

It holds print jobs so the processor can move on while the printer outputs the data at its own speed.

It stores a portion of data before playback to prevent pauses caused by network delays.

Buffers are used to synchronise data transfer between fast and slow devices.

Data could be lost or delayed if one device is not ready to process information.

They improve efficiency and avoid bottlenecks.

False.

A buffer is a temporary storage area that holds data only while it is being transferred.

RAM is primary storage directly connected to the CPU that holds the data and instructions currently in use.

ROM is primary storage that holds the first instructions a computer needs to start up, known as the bootstrap, and contains the BIOS.

RAM is very fast while ROM is slower than RAM; RAM holds gigabytes while ROM holds megabytes; RAM is read and write while ROM is read only; RAM is volatile while ROM is non-volatile.

They are both examples of primary memory.

Static RAM is a form of RAM that keeps data as long as power is on, made from flip-flops so there is no need for constant refreshing.

Dynamic RAM is a form of RAM that stores each bit in a tiny capacitor and needs constant refreshing to keep the data.

SRAM uses transistors arranged as flip-flops, while DRAM uses transistors and capacitors.

In cache memory, where quick access to data is most important, because SRAM is very fast — faster than DRAM.

As main memory, where larger amounts of cheaper storage are required.

It is expensive to make and takes up more space, giving a lower storage capacity than DRAM.

It is slower than SRAM because it needs time to refresh data, and it uses more power, especially during refreshing cycles.

They are all types of ROM that are programmed and reprogrammed in different ways, each with a specific application.

No — it is programmed once only and cannot be erased.

Using UV light, and the chip must be removed from the device, with the entire chip erased at once.

Using electric voltage, and it can be erased in place without removing it from the device, with specific parts erased rather than the whole chip.

Flash memory and BIOS chips, including smart cards, remote key fobs, USB sticks and SSDs.

False.

An EPROM has its entire chip erased at once; it is the EEPROM whose specific parts can be erased.

A monitoring system collects data continuously through observation, passively gathering data without interacting with or changing the environment.

A control system automatically manages or adjusts a process based on data collected from sensors, taking action if certain conditions are met.

A monitoring system does not take action based on the data collected, while a control system does interact with the environment.

Weather stations and patient monitoring in hospitals.

It collects data 24/7 on temperature, wind speed, humidity and rainfall, but the system does not react or change anything.

It records and displays data and alerts medical staff if readings go outside safe ranges, but it does not directly treat the patient.

It monitors room temperature using a thermostat, switches the boiler on if temperature drops below the set level, and turns the heating off once the target is reached.

It monitors soil moisture levels, activates sprinklers if moisture drops too low, and turns off the water supply once the soil reaches the correct level.

A sensor is an input device that measures a physical property of its environment, such as light levels, temperature or movement.

Output devices that carry out actions based on data from sensors, such as motors, heaters, valves and pumps.

It measures acceleration rate, tilt and vibration, and is used to detect sudden changes in vehicle movement or the orientation of a mobile phone.

It measures distance, and is used to monitor the position of objects in robotics and in safety systems to prevent collisions.

It measures acidity or alkalinity, and is used to monitor soil for optimum growing conditions and pH levels in chemical processes.

A feedback loop is when a control system uses its output to influence its next input, allowing it to automatically adjust and stay within set conditions.

In a feedback loop the output affects the next input, helping the system make adjustments.

False.

Feedback makes the system more accurate and efficient without needing human control — it self-corrects.