Hardware | 9618 CS P1

How does a 3-D printer work?

- The object is designed using computer-aided design software (CAD)
- the software splits the object into slices
- Data about the slices is sent to the printer
- solid plastic is melted and transferred to the nozzle
- a stepper motor moves the nozzle into position
- the nozzle extrudes the molten plastic
- previous steps are repeated until the layer is complete
- A fan cools the layer
- each layer is individually printed

How does a laser printer work?

- the revolving drum is initially given an electrical charge
- A laser beam bounces off of a moving mirror back and forth across the drum
- this discharges certain points (such as letters or images to be printed as electrical charges)
- the drum is coated with oppositely charged toner which only sticks to charged areas
- the pattern on the drum is transferred onto the paper
- the paper is passed through the fuser to seal the image

How does a 3-D printer work?

- The object is designed using computer-aided design software (CAD)
- the software splits the object into slices
- Data about the slices is sent to the printer
- solid plastic is melted and transferred to the nozzle
- a stepper motor moves the nozzle into position
- the nozzle extrudes the molten plastic
- previous steps are repeated until the layer is complete
- A fan cools the layer
- each layer is individually printed

How does a laser printer work?

- the revolving drum is initially given an electrical charge
- A laser beam bounces off of a moving mirror back and forth across the drum
- this discharges certain points (such as letters or images to be printed as electrical charges)
- the drum is coated with oppositely charged toner which only sticks to charged areas
- the pattern on the drum is transferred onto the paper
- the paper is passed through the fuser to seal the image

How does a microphone work?

- The microphone has a diaphragm
- the incoming sound wave causes vibration, causing a coil to move past a magnet
- an electrical signal is produced and coded into binary

How do speakers work?

- Speakers take in electrical signals and translate it into physical vibrations to create sound waves

- an electrical current in the coil creates an electromagnetic field
- Changes in the audio signal cause the direction of the electric current to change
- the direction of the current determines the polarity of the electromagnet
- the electromagnet is repelled by or attracted to a permanent magnet, causing the coil to vibrate
- the movement of the coil causes the cone to vibrate
- the vibration is transmitted to the air in front of the cone
- the amount of movement will determine the frequency and amplitude of the sound wave produced

What are the types of RAM?

Static RAM and Dynamic RAM (SRAM, DRAM)

What are the types of ROM?

PROM: programmable ROM

EPROM: erasable programmable ROM

EEPROM: electrically erasable programmable ROM

What is the difference between RAM and ROM?

- RAM is volatile/temporary memory
- ROM is non-volatile/permanent memory

- Data can be altered and ran in RAM
- Data cannot be changed in ROM

- RAM stores data in use
- ROM stores boot up instructions

- RAM is read/write
- ROM is read only

What are the uses of RAM and ROM in 3D Printers?

RAM:
- stores current running parts of 3-D printer software
- stores the content of the buffer
- stores the current progress of the printer
- stores data about the layers being printed
- stores the data about the printer (i.e toner level)

ROM:
- stores the operating system for the 3-D printer
- stores the setup instructions for the 3-D printer

What are the uses of RAM and ROM in Laser Printers?

RAM:
- stores current running parts of the laser printer
- stores the data being printed or data in the buffer
- stores the current progress of the printer
- stores the data about the printer (i.e toner level)

ROM:
- stores the operating system for the 3-D printer
- stores the boot up instructions of the printer

Explain the difference between DRAM and SRAM

- DRAM has to be refreshed
- SRAM does not require refreshing

- DRAM uses a single transistor and capacitor
- SRAM uses more than one transistor (arranged as flip flops)

- DRAM stores each bit as a charge
- SRAM stores each bit using flip-flop

- DRAM has a higher power consumption
- SRAM has less power consumption

- DRAM has slow access time as refresh is required
- SRAM has faster access time as no refresh is required

- DRAM has more storage
- SRAM has less storage

- DRAM is used in main memory
- SRAM is used in cache memory

What does PROM stand for and how does it work?

- programmable read only memory

- initially empty
- usery can write data on it only once
- if there's any error in writing instructions, the error cannot be removed and the chip becomes unusable

What does EPROM stand for and how does it work?

- erasable programmable read only memory

- initially empty
- can be overwritten multiple times
- if there is an error in writing instructions, the error can be removed
- EPROM can be erased using UV light
- EPROM needs to be removed from device
- EPROM must be entirely erased before writing

What does EEPROM stand for and how does it work?

- electrically erasable programmable read only memory

- initially empty
- can be overwritten multiple times
- if there is an error in writing instructions, the error can be removed
- EEPROM can be erased using voltage
- EEPROM can be erased in its original position
- EEPROM does not have to be entirely erased before writing

Explain the difference between PROM, EPROM and EEPROM

- prom can be set only once, while EPROM and EEPROM can be overwritten multiple times

- EPROM can be erased using UV light while EEPROM can be erased using voltage

- EPROM can be erased in its original position and does not have to be entirely erased before writing

What is a buffer?

Buffer memory is a temporary storage area in the RAM that stores data being transferred between two or more devices

A car has several features. One feature is a lane detection system. This system monitors the lines on either side of the lane. If the car gets too close to one line, the system automatically move the car away from the line. Explain why the late detection system is an example of an embedded system.

- it is built into the car
- it only performs one task
- it is not easily updated by the car owner