On the website of the University of Cologne’s Papyrus-Sammlung, an extremely important collection of ancient documents, high-resolution digital images of the Cologne Mani Codex are available:
http://www.uni-koeln.de/phil-fak/ifa/NRWakademie/papyrologie/Manikodex/bildermani.html
This important text, which has various significant lacunae, has received two editions (most recently by Ludwig Koenen and Cornelia Römer, Der Kölner Mani-Kodex [Opladen, 1988]), a diplomatic text, and multiple translations; now interested researchers will be able to consult the manuscript conveniently online.