The 645D and K-r manuals have been uploaded at the Pentax Japanese homepage:-
http://www.pentax.jp/japan/support/download_manual.html
Do note that the above page and manuals are in Japanese. As for the 645D manuals, there are two versions, one is the full manual and the other is an extracted version for menu operations and settings of the camera.
As for the English manuals, there is only the K-r one for the latest model, that has just been uploaded, in the following English page:-
http://www.pentax.jp/english/support/download_manual.html
There is no K-5 manual yet, neither in Japanese nor in English (which is usually uploaded later), but I think it will be uploaded soon, anyway.
Do read the manuals if you are really interested in any camera(s) or you have already owned some of them but yet have some questions. In fact, it is not difficult to see people keep asking simple questions that the user manuals had already told but then those people just usually tried to ask in the Internet instead of just reading their manuals first. Sometimes I just wonder.. If the Internet is really so useful and important? :-o ;->