Originally posted by TaiChiTom I always format my SD card in camera. When I insert my formatted SD card into my Mac and click on the Finder icon in the Dock the K-3 is shown as a device. When I click on the K-3 device a folder is displayed labeled DCIM. When I click on this folder it opens and is empty. This is where I put the .bin file. I don't see any indication of a root. As I recall this is the procedure I have followed with previous Pentax cameras and cameras from other manufacturers.
Put your .bin file OUTSIDE the DCIM folder. It should be visible next to the folder when the K3 Device is clicked. That is the Root Directory for the card - both the .bin file and the DCIM Folder will be in the Root Directory.
Doing that should rectify your problem.