The first ever modern computer was designed by Apple. In 1976's Apple I was the first computer sold with fully assembled circuit board, though consumers still needed to buy a case, power supply, keyboard, and display however. The first "modern" computer was really bad and took a long time to do any calcualtions. The big thing was that the computer was small and afforadle enough that people could now have computers as average citizens.
The Carter administration installed a computer in the White House. Staffers were given terminals to access a shared Hewlett-Packard HP3000 computer, and the technology department acquired a Xerox Alto for the Oval Office.
In 1980 commodore released the VIC-20 home computer and was the first computer to sell more than 1 million units making it very popular. Then in 1983 apple released Lisa the first commercial personal computer with a GUI or graphical user interface. This was very important as Microsoft and Apple would now use GUI as their user interfaces. Finally, in 1989 Nintendo released the Game Boy which today has sold more than 100 million copies today.