The famous "Solar Walkman" was indeed a technological marvel. ≡
First wired remote control, enabling the Walkman to be placed in your bag, but controlled from the outside.
The WM-F2 was a remarkably well-featured unit. Contained radio and could record, either from the radio or from an external source. ≡
The WM-F20 was very similar to the WM-F10. The only changes of note were that the hinges and slides were made a little stronger...
Radio Walkman with recording function and speed control, based on the WM-17
The first Walkman developed for use during outdoor activities. Marked the first appearance of the distinctive yellow seen in later sports models. ≡
Four-band radio of TV UHF/VHF, which can listen to the popular stereo music and television programs at that time.