Originally posted by THoog First, we need some more information:
Have you enabled "Using Aperture Ring" in the custom menu (option 16)?
What sort of M42 adapter - the ring type that sits flush in the mount allows infinity focus, or the flanged type that covers the contacts on the mount?
What sort of M42 lens - if you are using the ring type adapter, can the rear of the lens touch the lens contacts, and is it metallic or painted/plated?
Which camera mode? (Av/Tv/M)
If you haven't seen this thread, I recommend reading it:
https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/110658-u...x-dslrs-f.html As long as "Use Aperture Ring" is enabled for any adapted or manual lens, then SR should be possible. You don't even need to have a lens on the camera, actually.
So:
-- single shot drive mode
-- "use aperture ring" enabled
-- turn SR on (from the status/info screen) [if it was turned off, it will stay off until you turn it on again]
After you make sure it is on, you can turn the camera off/on again and it should ask for focal length (or you can enter it from the menu), but if SR is enabled at startup then it will ask. (I think the K-01 might ask even if it is not -- I suspect "use aperture ring" being turned off is the problem here).