Sony has announced an update to its popular MiniDisc (MD) digital music medium, turning it into a PC-compatible storage format as well as increasing the capacity of each disk. The move could offer mobile professionals a new option for backup and storage of files while on the road.

Hi-MD, set to appear in new Sony products this spring, enables MiniDisc media to be used for storing images and text files, while maintaining playback compatibility with current MD products, the firm said.

"The launch of the Hi-MD format, together with a range of Hi-MD Walkman products, will add a new dimension to the European portable audio arena," said Gregory Kukolj, group marketing manager for Sony personal audio in Europe.

Hi-MD users will be able to store data alongside audio tracks, so they could listen to music on the format while going to work, then transfer documents to their PC when they reach the office, the company said.

Sony's new Hi-MD format uses the FAT filing system that is widely used to store data on PC hard drives and other media.

Hi-MD also complies with the USB Mass Storage Class, which means that a Hi-MD device will be automatically recognised as an external storage device when connected to a PC or laptop USB port.

Hi-MD is compatible with current MiniDisc media, according to Kukolj. Formatting an existing disk under the Hi-MD format will almost double its capacity from 177MB to 305MB.

Kukolj added that Sony is also planning high-density MiniDiscs that will be capable of holding up to 1GB when formatted as Hi-MD.