1e en 3e zijn simpel, 1e is al verklapt, en 3e was een keer zoeken op ATRAC.
Nu de 2e nog

Hint vraag 1:
In May 1991, all development was concluded, and the MiniDisc (MD), the new audio standard, was announced. To enhance portability, the disc was housed in a shell. The MD combined recordable features of the cassette tape with the random access functions and high quality sound of the CD. Sony clearly explained the difference between the CD and MD; the CD was for leisure listening and the MD for enjoying music anywhere and anytime, much like the Walkman.
Maar de tegenspraak:
...the product launch for the end of 1992....
Hint voor vraag 3:
http://www.minidisc.org/
Ej doed, je 2e vraag sockt.
Er waren meerdere types
Consumers and the mass media had created a furor over MD since its product announcements in September 1992, and in November a full line of new MD products was launched in Japan, ahead of the US and Europe. The recordable/playback MZ-1 model, the playback only MZ-2P, and the record-only MDW-60 were delivered to retailers nationwide along with 88 titles produced by Sony Music Entertainment. A Try and Buy campaign for the MD that allowed customers to test the product was launched at major electronic appliance stores in Tokyo, Osaka and Nagoya. In December 1992, the recordable/playback and playback-only models were launched abroad with software titles.