Before operating systems, programmers had to manually reconfigure wiring and connections to run different programs on a computer. Early operating systems used punch cards or magnetic tapes to load programs into memory one at a time, wiping out the previous program. The first "boss" programs or operating systems allowed multiple programs to run simultaneously by controlling the other programs. One of the earliest operating systems for personal computers was Microsoft's MS-DOS, which required typing commands instead of using a graphical user interface. Later, operating systems incorporated mouse input and clicking interfaces instead of only text commands.

1. Operating Systems:
History
Before Operating Systems,
if you wanted to change
what the computer was
doing, you had to change
how the wires were
connected.
What were computers
like before operating
systems were invented?

2. Operating Systems:
History
Later, instructions were
given to the computer with
punch cards or magnetic
tape.
If you wanted to run a
different program, you had
to wipe out the first
program from memory and
then load another program
into memory.
Learn about the history of Operating Systems

3. Operating Systems:
History
Learn about the first Operating Systems
To run more than one program
at a time, you need a "boss"
program that controls all the
other programs.
Such a boss program is called
an operating system.

4. Operating Systems:
Microsoft MS-DOS
Learn about the first Operating Systems
Microsoft’s MS-DOS was one
of the first Operating Systems
for Personal Computers (PCs).
No mouse. Instead, you had to
type a lot of special computer
commands.

5. Clicking instead of
typing commands
Learn about the first Operating Systems
In the 1980s, operating
systems were developed
where you could move a
mouse around and click
on things instead of typing
commands.

6. Operating System:
Microsoft Windows 1.0
Learn More About Windows 1.0

7. Operating System:
Windows 2000
Learn More About Windows 2000

8. Operating System:
Windows XP
Learn More About Windows XP

9. Operating System:
Windows Vista
Learn More About Windows Vista

10. Operating System:
Windows 7
Learn More About Windows 7

11. Operating System:
Windows 8
for Laptops and Desktops
Learn More About Windows 8

12. Operating System:
Windows Phone 8
Learn More About Windows Phone

13. Operating System:
Google Android
for Phones and Tablets

14. Operating System:
Mac OS X
forDesktops and Laptops

15. Operating System:
Apple iOS
for Phones and Tablets
Learn more about Apple's iOS