At one point I had a solid-state Sony NW-MS7 Memory Stick Walkman (that wasn't quite an MP3 player because it was limited to only playing ATRAC files). For 1999

At one point I had a solid-state Sony NW-MS7 Memory Stick Walkman (that wasn't quite an MP3 player because it was limited to only playing ATRAC files). For 1999, it was a usable and forward-looking piece of tech. Pity they crippled it with aforementioned ATRAC-only encoding (requiring file format conversion and re-encoding) and expensive Memory Stick proprietary media.