There are slides devoted to this topic: Lecture 0, pp. 51-55, Lecture 10b. 

Websites

Check out the Computer History Museum‘s exhibit on the minicomputer, which includes pages on the Digital Equipment Corporation and the DDP-116, one of the first minicomputers

Learn about the PDP-1, the DEC’s groundbreaking minicomputer, in the”DEC PDP I” article on the History of Computers site. Afterwards, read about its successor, the DEC PDP II.

Books

Campbell-Kelly and Aspray, Computer: A History of the Information Machine, 198-204

The PDP-8: Freed, Less. The History of Computers: a family album of computer genealogy, 73-75