The Apple ][ is one of the first mass-produced computer systems in the world. It was designed by Steve Wozniak, with Steve Jobs overseeing the design of the case. The computer was introduced in 1977 at the West Coast Computer Fair. It marks Apple's first launch of a personal computer aimed at the mass consumer market. The vision was to have a computer for use in the home, rather than just for business or hobby enthusiasts.

The year 1977 was a defining year for the home computer market. The three main computer systems that were introduced that year are now considered part of the 1977 Trinity of computing:

• Commodore PET 2001
• Tandy Radioshack TRS-80 Model 1
• Apple II

The 6502 is an 8-bit MicroProcessor designed by MOS Technology. The team was led by Chuck Peddle and had also worked on the Motorola 6800. The 6502 is a simplified, but faster and cheaper design than the 6800.

The 6502 was introduced in 1975 and was the cheapest microprocessor on the market. Together with the Zilog Z80, the 6502 helped start the home computer revolution of the 1980s. The 6502 was used in a wide range of devices: the Atari 2600, the 8-bit Atari home computers, the Apple II, the Nintendo Entertainment System, the Commodore 64, the BBC Micro and many others. All used the 6502 or a variation of it.

The 6502 is a 1MHz design, while the 6502A is designed for 2MHz. The 6502A is 100% compatible with the original 6502.

Commodore soon bought MOS Technology, but conitnued to sell the microprocessor to competitors and licensed the design to other manufacturers.