3.1 Computers and their components Flashcards
Memory cache
high speed memory external to processor which stores data which the processor will need again
Random access memory (RAM)
primary memory unit that can be written to or read from
Read-only memory (ROM)
primary memory unit that can only be read from
Dynamic RAM (DRAM)
type of RAM chip that needs to be constantly refreshed
Static RAM (SRAM)
type of RAM chop that uses flip-flops and does not need to refresh
Refreshed
requirement to change a component to retain its electronic state
Programmable ROM (PROM)
type of ROM chip that can be programmed once
Erasable PROM (EPROM)
type of ROM that can be programmed more than once using ultraviolet (UV) light
Electronically EPROM (EEPROM)
a type of ROM that can be modified by the user, which can then be erased and written to repeatedly using pulsed voltages
Hard disk drive (HDD)
type of magnetic storage device that uses spinning disks
Latency
the lag in a system
for example, the time to find a track on a hard disk
Fragmented
storage of data in non-consecutive sectors
for example, due to the editing and deletion of old data
Removable HDD
portable hard disk drive that is external to the computer
can be connected using a USB part when required
often used as a device to back up data
Solid state drive (SSD)
storage media with no moving parts that relies on movement of electron
Flash memory
a type of EEPROM
particularly suited to use in drives such as SSDs, memory cards and memory sticks
Optical storage
CDs, DVDs, and Blu-ray discs that use laser light to read and write data
Duel layering
used in DVDs
meaning there are two recording layers
Birefringence
a reading problem with DVDs caused by refraction of laser light into two beams
Binder 3D printing
3D printing method that uses a two-stage pass
the first stage uses dry powder and the second stage uses a binding agent
Direct 3D printing
3D printing technique where print head moves in the x, y and z directions
layers of melted material are built up using nozzles like an inkjet printer
Digital to analogue converter (DAC)
needed to convert digital data into electric currents that can drive motors, actuators and relays, for example
Analogue to digital converter (ADC)
needed to convert analogue data (read from sensors, for example) into a form understood by the computer
Organic LED (OLED)
uses movement of electrons between cathode and anode to produce an onscreen image
generates its own light so no back lighting required
Screen resolution
number of pixels in the horizontal and vertical directions on a television/computer screen
