The Personal Computer
The microprocessor, Xerox PARC and the graphical interface, the Altair and hobbyist culture, Apple, Microsoft and the IBM PC, clones and the Wintel standard, spreadsheets as the first business software (VisiCalc), the Macintosh, Windows, and PCs reaching Nigeria and Africa through cybercafes and secondhand imports.
Computers for individuals
VisiCalc (1979), the first spreadsheet, was the "killer app" that made businesses buy Apple IIs. In Nigeria and much of Africa, personal computing spread in the 1990s and 2000s through business centres and cybercafes, then laptops and, overwhelmingly, phones (part 8).
Paul Freiberger and Michael Swaine, Fire in the Valley (2nd ed., 2000); Michael Hiltzik, Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age (1999); Walter Isaacson, The Innovators (2014).