I was checking bitsavers for CDC 6600 manuals. There are a lot of other models but nothing for the 6600. There is not on the web technically about the 6600 other than excerpts of Gordon Bell's book (which I have been reading "Computer Structures Readings and Examples, chapter 1-2, 39 touches on the 6600)
http://bitsavers.informatik.uni-stuttgart.de/pdf/cdc/ Here is a recent picture: http://vintagecomputer.net/pictures/2016/CHM_California/CDC_6600_system.jpg -- Bill Degnan
