1983 Sony Releases Posted on 16 February, 2004 by pocketcalculatorshow WM-6. WM-9. WM-20. WM-F20. WM-F5 water-resistant FM cassette player. WM-D6C quartz lock stereo recorder; Dolby B+C noise reduction. SEQ-50 five-band equalizer. Share this:PinterestFacebookTwitterTumblrEmail