I`m not a techie..but this does sound broad and it was before we saw any real handheld entertainment come out...
Samsung, Toshiba, Portalplayer-we worked with all of them.
-iam
1994-04-19 US1994000229731
Abstract: A record/playback device for use with a removable, interchangeable, flash memory recording medium which enables extended recording comparable with tape cassette dictating equipment. The device includes a housing, a microphone element, control circuitry and a switch mounted on the housing for selecting desired functional operations. A receiving socket is coupled to memory circuitry associated with the control circuitry and is configured for electrical coupling with a flash memory module adapted for receiving and retaining recorded digital information for storage in nonvolatile forme.