While not quite on that level, I used to use a Dell Axim x50 (Windows CE), a compact flash card full of mp3s and a cassette tape adapter. https://en.wikipedia.

While not quite on that level, I used to use a Dell Axim x50 (Windows CE), a compact flash card full of mp3s and a cassette tape adapter. https://en.wikipedia.org/wiki/Axim_X50_series https://en.wikipedia.org/wiki/Axim_X50_series