An operating system is

• a software that manages a computer ‘s hardware
• It also provides a basis for application programs and

  • acts as an intermediary between

  • the computer user and the computer hardware

    → 유저와 하드웨어의 매개 역할

Computer system can be divided roughly into four components

1. Hardware
2. Operating System
3. Application Programs
4. User

Defining Operating Systems

• 통상적으로 정의되지 않았음.

• More common definition is that

  • “the one program running at all times on the computer”
  • usually called the kernel

  → Along with the kernel, there are two other types of programs

  • system programs
  • application programs

What is bootstrap(부팅)?

• RAM은 휘발성이므로 ROM에 O/S 프로그램 존재

1. the first program to run on computer power-on,
2. loads the O/S

Interrupts

• Hardware may trigger an interrupt at any time

  → by sending a signal to the CPU, usually by way of the system bus