Conversation so far:
where was the first massed mp3 player sold
The world's first mass-produced hardware MP3 player was Saehan's MPMan, sold in Asia starting in the late spring of 1998.
how much did the mpman cost
For the 32 MB and 64 MB models of the MPMan, the prices were 39 800 yen (circa 400 USD - today $627.44) and 59 800 yen respectively.
why was the MPMan controversial
The RIAA's Associate Director of Anti-Copyright infringement initially said the MPMan had no function other than playing material that was stolen from record companies.
did the MPMan have any positive feedback
The RIAA's Associate Director of Anti-Copyright infringement also called the MPMan a unique device. It's something that we haven't seen on the market before.

Question: how was the device powered
Self-contained rewrite: how was MPMan powered