The binder contains nearly 190 pages of printed program listings, written in PDP-7 assembly code, and dating to approximately 1970, and represent some of the earliest Unix code. These programs were written by the first participants in the Unix effort at the Bell Telephone Laboratories, starting in 1969. Ken Thompson and Dennis Ritchie were the two central, and initial, participants. Other early participants include Rudd Canaday, Doug McIlroy, Brian Kernighan, Bob Morris, and Joe Ossanna. It is likely that much of the work represented in this binder is due to the work of Thompson and Ritchie.