I gathered this info from various internet sites before transfering audio interviews on Sony HI MD discs to MP3 format. I used my obsolete Sony portable minidisc recorder MZ-M10 to transfer files via my ten-year-old 13" MacBook, running OS X El Capitan (10.11.6). The Sony proprietary software for converting the files, Hi-MD WAV Importer no longer worked, so I had to find another solution.
This is how I transferred the files (August 2020):
* Download and instal Audacity 2.3.3. software. Go to:
> Transport
> Transport Options
> Tick Software Playthroug