Resources: Input and Output

Question 1

how does the OS interface with IO

Answer 1

streams and blocks

Question 2

give examples of stream devices

Answer 2

keyboard, screen, printer, network

Question 3

give examples of block devices

Answer 3

USB, DVD, magnetic disk

Question 4

how do we abstract IO so that the OS can interface with it

Answer 4

Device Drivers

Question 5

what are the 4 layers of the software stack

Answer 5

user level- buffering and spooling
system calls
device driver
interrupt handlers

Question 6

what are device drivers

Answer 6

hardware that translate between the OS and the hardware to allow them to interface. incorporate a buffer as part of DMA transfers

Question 7

what are the two methods of using peripherals

Answer 7

polling- busy wait loop to see if status has changed

interrupt driven- create a demand for attention.

Question 8

What is a DMA controller

Answer 8

moves IO data without processor intervention

Question 9

what is a disk

Answer 9

auxiliary memory that stores data in blocks.