Printer i. CD Writer j.
Input can be from a user, via keyboard, mouse, microphone etc.
When a computer is powered on, basic tests are ran to ensure components are operational. If the user is comfortable, the computer will tolerate the environment. I recommend a computer not be turned on and off more than once per day. When it's time to power off a computer, use the Shutdown procedure provided by the operating system. This ensures that all data is written to disk and an that programs are stopped in a orderly manner.