The Atari 410 Recorder was made for the Atari 400 and 800 computer systems. I originally picked one up to use with my Atari 800XL used for $35. I was so excited that I could actually save my programs. I still had to write all my own software, because there was no place to find programs on cassette tapes around where I lived. I got this one for I believe $5.
Atari 410 Recorder