I'm in an SLR mood this week. The Minolta XG9 was introduced in 1979. It is a manual focus, aperture priority camera with a manual override mode. Interestingly, the meter does not function in the manual mode. The shutter is electronic and will not function without batteries.
One interesting feature is the metering. Simply touching the shutter button causes LEDs to light in the viewfinder displaying the selected shutter speed.
My example is a $10.50 eBay impulse buy which came with a 45mm f/2 prime lens. I've belatedly loaded it with July's #FeaturedFilm, Fuji Velvia 50.
The Minolta XG series at Camera Wiki.
In-depth article on the XG series at the Rokkor Files.
Manual from Mike Butkus
and the eBay link.