Thanks to a collaboration between two vintage computer museums, the source code for the Apple II DOS, which is widely regarded as the seed that sprouted Apple as know it, has been made available to the public. The Computer History Museum with the help of DigiBarn Computer Museum, recently posted the Apple II disk operating system for non-commercial use. Apple had given the publication the consent to do so as the company still owns the code.

For those of you who didnít already know, the Apple II was a fully-assembled personal computer with a number of advance features such as a built-in BASIC programming language, compatibility for an external monitor and various modes of input. The machine lacked a disk drive, which meant that programs and data had to be stored and retrieved via cassette tape.

To provide some historical insight to the situation: Apple cofounder Steve Wozniak created a floppy disk controller for the Apple II in 1977 but needed a DOS to access and organize the associated programs and data. This task was handled by contract program Paul Laughton, who at the time worked for Shepardson Microsystems. In 1978, Steve Jobs inked a $13,000 deal with Bob Shepardson to provide a file manager, BASIC interface and utilities, with a delivery date pegged for seven weeks later. Laughton said he had to write the DOS on punch card sheets, which were assembled and made into a paper tape able to be read by a plug in card created by Wozniak. The process was repeated throughout debugging and updating. After a few weeks of coding, the Apple II DOS 3.2 was released in June 1978.

The source code can be downloaded via The Computer History Museumís website, while documents relating to the software, including schematics and business agreements, can be found on DigiBarnís website.

Source: The Computer History Museum, DigiBarn Computer Museum