Musicard

The Musicard is a music format invented by Theorysonic in 1997 and released in 1998. The format is a standard flash card format, measuring 3.5 by 3.5 cm in diameter. The cards can only be read on dedicated players such as the Portosic MC, or through a driver hooked up to a computer. Musicards only support MP3 format when writing to them.

The Musicard was exported and marketed in the US as the Theory Musicard by SanDisk. As of 2019, the Musicard continues to be manufactured and sold, albeit to a niche market.