Introduction to Operating Systems Flashcards
Give the definition of operating systems
= program that controls the execution of application programs and acts as an interface between the user of a computer and the hardware.
= the one program running at all times on the computer (usually called the kernel), with all else being application programs.
= concerned with the allocation of recources and services, such as memory, processors, devices and information.
The OS correspondingly includes programs to manage these recources,
such as:
traffic controller, a scheduler, a memory management module, I/O programs, and a file system
Name 4 features of OS + explain
- convenience ->
An OS makes a computer more convenient to use. - efficiency ->
An OS allows the computer system resources to be used efficiently. - ability to evolve ->
An OS should be constructed in such a way as to permit the effective development, testing, and introduction of new system functions at the same time without interfering with service. - throughput ->
An OS should be constructed that it can give max throughput (Number of tasks per Unit time)
Name 5 major functionalities of OS
- resource management
- process management
- storage management
- memory management
- security/privacy management
(refer to summary pg 1 for full explanations, should be able to explain all 5 functionalities)
What does every general-purpose computer consist of ?
hardware
operating system(s)
system programs
application programs
hardware in computer consists of ?
memory
CPU
ALU
I/O devices
peripheral devices
storage devices
the system program consists of ?
compilers
loaders
editors
OS
etc.
the application program consists of ?
business programs
database programs
explain assembler
input = assembly language program.
output = object program + information that enables the loader to prepare the object program for execution
explain compiler and interpreter
the high level languages are processed by compilers and interpreters.
- A compiler is a program that accepts a source program in a “high-level language” and produces a corresponding object program.
- An interpreter is a program that appears to execute a source program as if it was machine language. The same name is often used to designate both a compiler and its associated language.
explain loader
= a routine that loads an object program and prepares it for execution.
- there are various loading schemes: absolute, relocating, direct-linking.
- in general, the loader must load, relocate and link the object program.
- The loader = program that places programs into memory and prepares them for execution.
(see summary pg 4 for more info)
What electronic device was used in the first generation (1945-55) ?
What type of OS devices ?
vacuum tubes
plug boards
What electronic device was used in the second generation (1955-65) ?
What type of OS devices ?
transistors
batch systems
What electronic device was used in the third generation (1965-80) ?
What type of OS devices ?
inegrated circuits (IC)
multiprogramming
What electronic device was used in the fourth generation (since 1980) ?
What type of OS devices ?
large scale integration
PC
Name 5 types of OS
batch operating system
time-sharing operating system
distributed operating system
network operating system
real-time operating system
explain batch OS
sequence of jobs in a program on a computer without manual interventions
explain time-sharing OS
allows many users to share computer resources.
(max utilization of the resources)
explain distributed OS
manages a group of different computers and makes appear to be a single computer
explain network OS
computers running in different operating systems can participate in a common network. (Used for security purposes)
explain real-time OS
used where any or all the jobs have strict time constraints.
