Sony has packed a lot more into its mini-disc digital music players.
Sony has learnt from others that use hard drives or memory cards
The Japanese electronics giant has developed a new format which can store up to 45 hours of music on a single disc, as well as pictures and text.
The new Hi-MD players and discs will be available from April, Sony said at the Consumer Electronics Show in Las Vegas.
The mini-disc walkman has been facing tough competition from portable MP3 players, like Apple's iPod, which holds up to 10,000 songs on a hard drive.
"With Hi-MD players, we're giving music lovers more choices," said Todd Schrader, Vice President of Marketing for Sony Electronics' portable music range. "Nothing's been left out."
The new format can pack a gigabyte of data onto a disc, amounting to 45 hours of music compressed at 48Kbps.
This compares to 13 hours of music on a standard 80-minute mini-disc encoded at the same rate.
The new machines will be able to play both new and old discs and have built-in copyright protection.
Sony has learnt from the example of digital music players that use hard drives or memory cards to store music.
New Hi-MD recorders can act as external hard drives
The new Hi-MD recorders will be able to act as external hard drives, letting people store photos, presentations or documents on a disc.
These can be transferred to a PC via a USB cable, which will also power the player.
The entry-level model of the new players will cost around $200, while Hi-MD discs are expected to cost about $7 each.
"We've created the best overall portable music solution that addresses digital music fans' needs for high capacity storage and long battery life in a small and extremely durable device," said Mr Schrader.
Sony will be looking at the new high density format to breathe fresh life into its mini-discs.
The new format comes as rival portable music players grow in popularity.
Products like Apple's iPod have been a runaway success and have eaten into Sony's market share.
Sony estimates that global sales of mini-disc players and recorders from all manufacturers have totalled about 80 million since the devices went on sale in 1992.
The company expects to sell more than seven million mini-disc players worldwide in the financial year ending in March.