Computer Science 9618 - Hardware and Memory

Vocabulary flashcards covering core hardware components, memory types, touchscreens, optical/secondary storage, and embedded systems from Computer Science 9618 Paper 1.

3D Printer

An output device that creates three-dimensional solid objects from a digital model designed using Computer-Aided Design (CAD) software, which splits the object into slices and extrudes molten plastic layer-by-layer using a stepper motor.

Laser Printer

A printer that uses a laser beam and a rotating mirror to draw an image as an electrostatic charge pattern on a photosensitive drum, which attracts oppositely charged toner before transferring it to paper and sealing it with a fuser.

Microphone

An input device containing a diaphragm that vibrates when sound waves strike it, causing a coil to move past a magnet (or changing capacitance) to create an electrical signal.

Speaker

An output device that converts an electrical signal into physical vibrations by altering the current direction in a coil to change the polarity of an electromagnet relative to a permanent magnet, vibrating a cone to produce sound waves.

Resistive Touchscreen

A touchscreen consisting of a flexible top polyester film and a bottom glass layer separated by an air gap; touching the top layer completes a circuit, allowing a microprocessor to calculate horizontal and vertical coordinates.

Capacitive Touchscreen

A touchscreen made up of multiple glass layers that store electrical charge; touching the screen changes the electric current, enabling a microprocessor to calculate the touch coordinates.

Virtual Reality (VR) Headset

A wearable hardware device featuring LCD screens, surround sound speakers, and motion sensors (such as gyroscopes or accelerometers) to track head direction and speed for immersive simulations.

RAM (Random Access Memory)

Volatile, read/write primary memory used to temporarily store data, programs, and operating system instructions currently in use.

ROM (Read Only Memory)

Non-volatile, read-only primary memory used to permanently store start-up instructions (BIOS) and the OS kernel.

DRAM (Dynamic Random Access Memory)

A type of RAM constructed from a single transistor and capacitor per bit that stores data as an electrical charge and requires constant refreshing.

SRAM (Static Random Access Memory)

A fast, high-cost type of RAM constructed using transistors arranged as flip-flops; it holds data without needing periodic refreshing and is primarily used in CPU cache memory.

PROM (Programmable Read Only Memory)

A type of ROM chip that is initially blank and can be programmed by a user only once; errors made during writing cannot be erased, rendering the chip unusable.

EPROM (Erasable Programmable Read Only Memory)

A type of ROM chip that can be erased using ultraviolet (UV) light and rewritten, but must be removed from the circuit board and completely erased prior to rewriting.

EEPROM (Electrically Erasable Programmable Read Only Memory)

A type of ROM/flash memory that can be erased and reprogrammed using electrical voltage in situ without removing the chip or fully erasing the contents first.

Buffer

A temporary storage area within RAM used to hold data transferring between components operating at different speeds, preventing slower peripheral devices from stalling processor activity.

Hard Disk Drive (HDD)

A magnetic secondary storage device using spinning platters coated with ferrous-oxide, read/write heads mounted on an actuator arm, and tracks divided into sectors to store magnetic data blocks.

Solid State Drive (SSD)

A non-volatile secondary storage device with no moving parts that utilizes floating gate and control gate transistors within NAND or NOR flash memory grids to control electron flow.

DVD-RW

An optical disc format with a single spiral track and $4.7\,GB$ capacity that utilizes phase-change recording layer technology and requires existing data to be completely erased before writing new data.

DVD-RAM

An optical storage disc with concentric tracks split into sectors, supporting simultaneous read/write operations at a constant rotational speed with a capacity of $4.7\,GB$ per side.

Embedded System

A specialized combination of a microprocessor, memory, and input/output capabilities integrated into a larger device to perform one specific dedicated function.