Section 18.5
Review Questions
Device Drivers and System Calls
  1. What is a device driver?
answer...
a subroutine in the operating system that allows the operating system to communicate with peripherals
  1. How does UNIX get input from almost every peripheral?
answer...
by using the read() system call
  1. Peripheral devices are usually composed of what two pieces?
answer...
the actual device and a controller
  1. What is a controller, really?
answer...
it is an intelligent electronic device, sometimes an entire microprocessor
  1. Why are controllers necessary?
answer...
because the management of the actual peripherals is so minute and so exacting that it is difficult to get right.
  1. Who writes device drivers?
answer...
programmers who are experienced and who love minute, tedious detail
  1. Why is device driver code different than run of the mill code?
answer...
It must be very reliable and efficient.