The Computer History Museum in Mountain View has announced that the source code of the DOS 3.1 version released in June 1978 for the legendary Apple II, first marketed in 1977, has been made available for non-commercial use with permission of Apple Inc. and programmer Paul Laughton.

Unlike its predecessor (Apple I), the first computer to be mass-marketed was fully assembled, and could be connected to a display monitor. The version with 4K memory cost 1298 US dollars. This machine, a pioneer of the time, had many advanced features (colour, graphics options, expansion slots, built-in BASIC, etc. ) but it did not have a disk drive. Programs and data had to be saved on cassettes, which turned out to be a slow and unreliable process. The problem was that disks, even floppy disks, required expensive hardware controllers and complicated software. This time, like so many times in the early years of Apple, it was Steve Wozniak who came up with a solution. Or at least he found a solution to one half of the problem: he designed a floppy disk controller using only eight integrated circuits, which, together with some simple software (written by Wozniak and Randy Wigginton) was exhibited at CES in January 1978.

But how were they to go about getting higher level software to organize and access programs and data on the disk?, was the question raised for the other half of the problem, which still needed to be solved.

Apple had only 15 employees, and none of them had the skills and time to write the software. In the end, Steve Jobs contacted the programmer Paul Laughton, who worked for Shepardson Microsystems, a company that was based in Cupertino just like Apple. Jobs and Laughton signed a 13 thousand US dollar contract on 10 April 1978. Laughton was given astonishingly short time, 15 May as deadline, to prepare the file manager, BASIC interface and utilities. Even more astonishing is the fact that Laughton successfully fulfilled the task, and Apple II DOS 3.1 was released in June 1978.

It is the source code of this version that has become public property now.