9 - External Hardware Devices & Storage Flashcards
(18 cards)
What are two advantages of purchasing a file server that uses SSDs?
- Lower power consumption
- Faster access times, transfer rate, lower latency
What are two disadvantages of purchasing a file server that uses SSDs?
- Higher cost per megabyte
- Higher error rate over time
What type of media does a hard disk drive use?
Magnetic media
What type of media does a CD-ROM use?
Optical media
What is one key difference in how data is read between hard disk drives and CD-ROMs?
Hard disk drives use magnetic induction, while CD-ROMs use a laser and sensor.
Fill in the blank: A hard disk is split into ______, whereas a CD-ROM follows a spiral track.
sectors/tracks
How is data access speed different between hard disk drives and CD-ROMs?
Hard disk drives can transfer/access data faster than CD-ROMs.
Why is the storage capacity for a DVD disk larger than that of a CD?
- Spiral spacing on DVD is closer/smaller
- DVD is multi-layered/double-sided
Define a peripheral.
A (hardware) device that is not part of the CPU and is external.
What is one difference between primary and secondary storage?
Secondary storage is non-volatile, while primary storage is volatile.
True or False: Secondary storage is directly accessible to the processor.
False
List the steps involved in the operation of an RFID system.
- Reader sends radio frequency energy/wave
- Energy reaches the RFID tag’s antenna
- RFID tag is energised by the reader
- Transponder sends the data signal
- Reader receives the data signal near the exit
What is a key characteristic of how data is stored in an SSD?
Data is stored electronically with no mechanical/moving parts.
What must be done before a block of data can be overwritten in an SSD?
A block must be erased.
Describe how a laser printer operates.
- Bitmap of image built in memory
- Negative charge applied to drum
- Laser beam directed at drum
- Charge neutralised where laser strikes
- Negative charge applied to toner
- Toner sticks to drum based on charge
- Paper passed over drum to transfer toner
- Positively charged transfer roller assists transfer
- Heater fuses toner onto paper
- Four different colour toners required for colour printing
Describe how a digital image is captured by a digital camera.
- Light enters through the lens
- Each sensor produces an electrical signal
- Signal represents a pixel
- ADC converts light intensity into binary data
- Colour filter generates separate values for RGB
- Pixels recorded as a group/array
How does an optical disk drive read data from a disk?
- Low power beam of laser is shone at disk
- Light is focussed on the track
- Some light is reflected back
- Amount of light reflected is measured
- Disc spins at constant linear velocity
How is data represented on an optical disk?
- Data is stored on a spiral track
- Continuation of land/pit reflects light
- Transition between land and pit indicates a 1, continuation represents 0
