In 1959, Yashica released a single lens reflex camera - the Pentamatic. This was an eye level reflex, with bayonet mount lenses, and a front shutter release. The standard lens was semi automatic, but other lenses were preset diaphragm only.
I bought this example without a lens, and later aquired a 135mm lens in Pentamatic mount, a "T" mount adapter for Pentamatic, and a home made adapter which allowed M42 lenses to be mounted on the camera.
After a few years Yashica replaced the Pentamatic with a similar camera, which had M42 mount lenses.
This is Yashica's replacement for the Pentamatic - the Reflex 35J. This was styled very like the last model of Pentamatic (the one above is the first model). Yashica went on to produce a range of M42 lens mount cameras during the 1960s, and into the 1970s.
I do have other cameras!