Don't forget the adapters that plugged into the 1/8" jack on your Sony WalkMan with a cassette shaped adapter that went into the tape deck. There are also those weird devices that plugged into the 1/8" jack with a low power radio transmitter to tune your in dash receiver to hear. (A local station I listen is on the low end where these devices operate. The station is lower powered college station with the transmitter located where I'm pretty close to the edge of its range. From time to time at stop lights, a stronger signal will come in to interrupt and disappears after the green and cars separate. I'm guessing one of these is being used)