Lovely! The Pentax ME was the first Aperture Priority SLR and I bought one when they came out. It was succeeded by the ME Super, and I can't for the life of me remember what the difference was now. :shrug:
The ME though was just AP with no other options, so the only settings you had were ASA, (Film Speed) aperture, and exposure compensation. The metering pattern was centre weighted with a bias towards the bottom of the screen, not as sophisticated as most modern matrix systems. I think it was the smallest SLR ever made.
It's sister camera was the MX - one of the best Manual cameras ever made.