| In 1998, Rio introduced the Rio PMP300, the second | | | | made, it shipped with 32 Mbytes of internal memory |
| portable consumer MP3 digital audio player. This | | | | with a SmartMedia slot, where its users could add |
| development made them the first pioneer in portable | | | | more memory of one more 32Mbytes card. This $200 |
| digital audio in 1998, with a goal of "putting the most | | | | device was powered by a single AA battery for eight |
| effective technology in the hands of the people". The | | | | to twelve hours of playback time. |
| first MP3 portable player was actually developed my | | | | What Rio was most known for was the paving the |
| SaeHan Information Systems in Seoul, Korea – | | | | way for the development of the MP3 portable player |
| imported by Eiger Labs, Inc. Its development, the | | | | market for the average mainstream. Without the |
| MPMan, measured at 97 mm tall by 70 mm wide, by | | | | resources to compete with the main portable players, |
| 16.5 mm thick, while weighing 2 ounces. The MPMan | | | | Apple, Philips, and Creative – Rio went the route |
| did not become successful, due to the rapid rise of the | | | | of competing to be the leader in the compact, durable |
| Rio PMP300, which was developed soon afterward. | | | | player. When the Recording Industry Association of |
| With a size of 3.5" x 2.5" x .625" thick, the Rio PMP300 | | | | America filed a lawsuit against them in October 198, |
| was black with an LCD screen, and a circular pad with | | | | claiming the MP3 player violated the 1992 Audio Home |
| control buttons. These controls were used for moving | | | | Recording Act, the road was wide open when the |
| the tracks forward and backward, repeat, random | | | | three judge panel ruled in favor of Diamond Rio's |
| play – with four preset equalizer settings. There | | | | development. Rio is owned by the Japanese firm, |
| were no artist or title information on the screen, but it | | | | D&M Holdings, who in August 2005, said they |
| did display the track number played. This MP3 player | | | | would discontinue making MP3 players for business |
| supported MP2 and MP3 format audio files. When | | | | reasons, and moving into another direction. |