A MiniDisc is a storage device initially developed by Sony. MiniDiscs were introduced in 1992 and designed to replace cassette tapes for audio recording and playback, with a data version being brought to market in 1993. However, other data storage systems grew more popular than the MiniDisc and the technology quickly became viewed as obscure. It can be difficult to find MiniDiscs as well as players or recorders which can function with them.
The design of a MiniDisc includes a disc which is inside a cartridge about the size of a traditional floppy disc, another example of a storage medium which is rarely used today. MiniDiscs were designed to be readable and writable from the start. To record data, a laser is used to soften the disc, and a magnet is used to encode the data. This makes it a magneto-optical storage device. MiniDiscs include a small area which can be used to embed a table of contents or tracks in data form so that people know which track on the disc to access in order to listen to something specific.
One advantage of the MiniDisc is that it is far less likely to skip, and it can be used easily for activities such as field recording. This format is also widely regarded as highly stable. However, Sony's initial release of the product was cumbersome. People had to use Sony's adaptive transform acoustic coding (ATRAC) format for recording, and had to record in real time. It was also difficult to transfer data from a MiniDisc to another medium, such as a hard drive.
The MiniDisc became superceded by technology such as CDs and portable flash memory. Flash memory in particular rapidly became a popular data format upon its introduction thanks to the extreme portability and ease of use. The ability to readily transfer data to and from flash drives was also very appealing to many users.
In the early 2000s, Sony introduced the HI-MD, the descendent of the MiniDisc. This product has a lot of similarities, except that it is designed to work with more compression formats, to allow people to transfer data more easily, and to allow people to store a mixture of data types such as video, audio, and plain data, on a single disc. HI-MD players and recorders are also capable of reading older MiniDiscs, addressing the concerns of some consumers who were worried that their data might become unrecoverable without support for the original MiniDisc.