Section 4 device op and embedded systems

Question 1

Hard disk drives (HDD)

Answer 1

Drive read/write move into position like record player, movement takes additional time
Magnetic platter stores data. Affected by heat and magnetic fields iron particles on disk are magnetised to be either north or south. representing 0 or 1

Question 2

Solid state disk(SSD)

Answer 2

Look like a standard circuit board. They use electrical circuits to persistently store data. These use microscopic transistors to control the flow of current. One that allows current to flow is 1. Where current is blocked is 0

Question 3

Optical drives(CD/ Blu-ray)

Answer 3

Uses a laser to reflect light off the surface of the disk. One long spiral track contains pits and lands. When laser beam hits the curved start or end of a pit, the light is refracted on a 1 is recorded.where light is reflected from an area of the track with no pit a 0 is recorded

Question 4

Embedded Systems

Answer 4

Control for specific devices for e.g. In the home devices. Dont need OS as their inputs are specifically controlled by a button or switch

Must be reliable as they can’t be modified once manufactured

Question 5

What software is developed for embedded systems?

Answer 5

Assembly language develops software for these systems

Question 6

E.g. for embedded systems

Answer 6

air conditioning, heating systems, radio, alarm clocks, washing machines, fridges, microwave ovens

Question 7

Non-embedded systems

Answer 7

are general-purpose systems. The software is usually installed on an SSD or HDD. They can be used for a variety of tasks

Question 8

E.g. for non-embedded systems

Answer 8

PCs, smartphones, tablets and Rasberry Pi computers