Rio PMP300 Drivers

The Rio PMP300 was the first portable consumer MP3 music player, and was produced by Diamond Multimedia. It shipped in 1998 and not without controversy.

Roughly the shape of a deck of cards (3.5 inches by 2.5 inches and 0.625 inches thick) it was black and had an LCD screen and a circular pad with control buttons. It had controls for skipping tracks forwards or backwards, repeat, random play and for four preset equalizer settings. The LCD displayed the track number being played, but did not display artist or title information. It could play MP2 and MP3 format audio files, and had support for a variety of bit-rates and had MP3 variable-bitrate (VBR) support.

It shipped with 32 Mbytes of internal memory and had a SmartMedia slot, allowing users to add additional memory (up to another 32Mbytes - larger cards are not recognized by the Rio's firmware). It was powered by a single AA battery which provided between 8 and 12 hours of playback time. Connection to a personal computer was through the computer's parallel port, with a proprietary connector on the Rio's edge.

The Rio retailed for US $200, which made it quite expensive for the ability to play a dozen or so songs. An even more expensive version was later released, and was colored translucent green and equipped with a larger 64 Mbyte internal memory, though all of this came at a higher cost of $250.

Diamond no longer provides support for the Rio, and Diamond's Rio software doesn't work on later versions of Microsoft Windows, particularly Windows XP. Consequently owners wanting to keep their Rio working use independently produced freeware programs such as "Dreaming of Brasil" to download audio files to the player. Similarly, limited Linux command-line based support for the Rio is provided by the rioutils package.

In October 1998, the American recording industry group, the Recording Industry Association of America, filed a lawsuit in the Ninth U.S. Court of Appeals in San Francisco claiming the player violated the 1992 Audio Home Recording Act. The three judge panel ruled in favor of Diamond, paving the way for the development of the MP3 portable player market.

Basic Specs:

System Requirements

  • To get quality performance from Rio, the following (minimum) system is recommended:
  • Pentium 90MHz or faster
  • Windows 98/95
  • 20 MB free hard disk space
  • 1 available parallel port
  • CD-ROM drive (some drives may not accept encoding of MP3 files, see for more information)
  • 1 installed sound card


Rio PMP Hardware Specifications:

  • Size: 3.5” x 2.5” x 5/8”    
  • Weight: 70grams (2.4 ounces)
  • Onboard memory: 32MB, upgradable    
  • Battery: single 1.5V AA (alkaline type recommended)
  • Slots: 1 external flash memory    
  • Parallel port Transfer rate: 100Kbps (about 6 MB/minute)
  • Total Harmonic Distortion: 0.01 - 0.1%    Signal-to-noise ratio: >90dB
  • Connectors: Headphone,15-pin data transfer cable connector    
  • Accessories: Headphones; 15-pin data transfer cable; parallel port adapter


Memory and Audio Quality Tips

As discussed in the From CD to Rio section, making music for Rio memory and MP3 quality are related.  The higher the quality you want, the higher the bitrate needed. This leads to more data storage, and memory requirements. For the Rio player, the amount of memory is equivalent to audio playback time. With Rio, you can intermix files created at different data rates. Intermix the data rates to get the best audio performance for a given piece or type of music. Most pop music will sound very good at 64Kbit MP3 encoding rates.

The Rio’s internal memory is 32Mb, files at the 64Kbps data rate.  Below is a table of data rates, memory usage and times.

MP3 data encoding rate (Kbps)    MB/Min    Min/MB    Min/32MB    Min/48MB

  • 30                                                   0.219727    4.551111    145.6356    172.9422
  • 48                                                   0.351563    2.844444    91.02222    108.0889
  • 64                                                   0.46875    2.133333    68.26667    81.06667
  • 80                                                   0.585938    1.706667    54.61333    64.85333
  • 112                                                  0.820313    1.219048    39.00952    46.32381
  • 128                                                 0.9375    1.066667    34.13333    40.53333
  • 256                                                 1.875    0.533333    17.06667    20.26667
  • 320                                                2.34375    0.426667    13.65333    16.21333

As can be seen the lower the bitrate (Kbps), the greater the playing time that can be stored in the Rio player. In general, if quality is not of major importance, use a lower bit rate.

Diamond Rio PMP300 View of Player and Parallel Adapter.