1979 Entex Handheld 1 or 2 player Baseball Game:
This was a great game. For 1 player, you'd switch to auto function, and the pitches came automatically. For 2-player play, you'd switch to manual play, and the person pitching can remove the top portion, which is connected by 26" cord inside, and select from 5 pitches...curve, slider, fastball, change-up, and knuckler. I have to 'fess up that I'm copying the description from an ebay listing, but I did have this game and played it for a long time. The ebay listing is here.