Steve Jobs and Steve Wozniak with the Original Apple-1 Circuit Board

Apple is commemorating 50 years of technical innovation, tracing its origins to the 1976 release of the Apple I. The Apple Computer 1, often called the Apple I, was an 8-bit personal computer designed by Steve Wozniak and released by the Apple Computer Company in July 1976.

The company was initially established to sell the Apple I as its first product. The idea to form a business and market the computer came from Steve Jobs, a friend and co-founder alongside Wozniak.

Technical Specifications and Design

The Apple I was not a complete computer in the modern sense, but arrived as a motherboard-only personal computer kit. It consisted of a naked circuit board containing approximately 60 chips.

The system was built around the MOS 6502 microprocessor. While some records list the clock speed at 1 MHz, the National Museum of American History specifies the processor ran at 1.023 MHz.

The machine featured 4 kilobytes of memory, which was sufficient to run BASIC. This memory was expandable to 8 kilobytes on the board or up to 64 kilobytes through the use of expansion cards.

Storage for the Apple I included 256 bytes of ROM. For removable storage and programming, a cassette interface was available via an expansion slot, allowing users to load the BASIC interpreter without manual programming.

The Video Terminal Breakthrough

The key technical differentiator of the Apple I was the inclusion of video display terminal circuitry. This innovation allowed the computer to connect to a keyboard and a low-cost composite video monitor or a standard television screen.

At the time, most other early personal computers required expensive accompanying terminals, such as the Teletype Model 33. The Apple I and the Sol-20 were among the first home computers to offer the ability to see characters appear instantly on a screen as they were typed.

Wozniak designed the machine based on two primary principles: minimizing the number of chips to keep the machine affordable and ensuring it could output video to television screens that most users already owned.

Development and Early Production

Wozniak originally designed the Apple I in 1975 for his own personal use to play games and access the ARPANET. He wrote the BASIC interpreter and the system monitor by hand in machine code, often without a physical prototype.

Before founding Apple, Wozniak offered the design to his employer, Hewlett-Packard, on five separate occasions, but the company rejected it every time.

The decision to manufacture the machine was prompted by the enthusiastic reception Wozniak received from members of the Homebrew Computer Club in Silicon Valley. To fund the development of the Apple I, Wozniak and Jobs sold personal possessions for a few hundred dollars.

Early production was a labor-intensive process. Wozniak and Jobs, occasionally assisted by family members and friend Daniel Kottke, hand-soldered the components onto the printed circuit boards. Wozniak personally conducted final quality control, checking each unit for faulty chips and solder bridges.

The Apple I was sold as a single board for $666.66, a price point Wozniak chose because he liked repeating digits. To complete the system, the board required an ASCII encoded keyboard, a video display monitor, and an AC connected power unit supplying 28 volts at 1 amp and 8 volts at 3 amps.

The Apple I was discontinued on September 30, 1977. Between 175 and 200 units were sold before it was succeeded by the Apple II.