MiniDisc tech specs
The MiniDisc was an underrated digital audio format invented by Sony. A MiniDisc was like a CD, only smaller, in a protective caddy, and rewritable. This was during the 1990s, when CD-R drives were still prohibitively expensive, let alone CD-RW drives.
At the time, most people listened to music on either pre-recorded vinyl records or CDs, or re-recordable, portable cassette tapes. MiniDiscs combined the best parts of everything: the high fidelity of digital audio, the random access of discs, and the recordability that had previously been exclusive to tapes. They were also arguably the pinnacle of Sony's design aesthetics. Even the blank discs came in a variety of designs, each more futuristic and stylish than the last.
Just about the only downside at the time was that they used lossy compression, Sony's proprietary ATRAC. This made the format less suitable than DAT for field recordings, although as a portable consumer format it was a big leap from analogue cassette tapes.
MiniDiscs were the culmination of twentieth century consumer audio formats, the end of an era in which people would buy an album as a physical artefact, and then copy it to a more portable format. It was usurped only by MP3 players such as the iPod Mini, that could hold an entire music collection at once.