CD-MRW Format

Source: Philips

- Introduction:
The Mount Rainier Technical Group is an industry organization that has defined a defect managed format for standard CD-RW media. The format is named CD-MRW (Mount Rainier RW).

Mount Rainier enables native OS support of data storage on CD-RW. This makes the technology far easier to use and allows the replacement of the floppy. This is done by having defect management in the drive, by making the drive 2k addressable, by using background formatting, and by standardizing both command set and physical layout. The new standard is promoted by Compaq, Microsoft, Philips, and Sony and is supported by 38 industry leaders: OS vendors, PC-OEM's, ISV's, chip makers, and media makers.

- How this will come in the market?

With new recorders under the "CD-MRW" code name. These new CD-MRW ("M" is short for "Mt. Rainier") disc drives include defect management, and address the disk interchange problem by specifying the UDF format for use on CD-RW disks to ensure a standard for disk interchange between different computer systems. To take advantage of these new features, the drive requires a new type of software to support CD-RW media.

- In which RW format can be used?

Mt. Rainier can be used in both 1-4x and 4-10x (HS-RW) formats. The file system of the Mt. Rainier format would be, UDF 1.02 or 2.01.

- What's new?

The Mount Rainier project has 5 key elements:

- Physical defect management by the drive
- Logical write-addressing at 2k
- Background formatting
- Command set implementation
- Compatibility and standards-compliance

Defect Management in the Drive

In the last few years, several solutions have been developed to allow easy drag & drop writing upon both CD-R and CD-RW media. Most solutions are based upon UDF v1.50, which includes defect management. However this is done by the software not the drive. A drive which includes defect management will handle them easier and quicker. Also that makes the file-system and the compatible applications since they don't have to knowledge of the drive/media defect characterization & capabilities. CD-ROMs have no knowledge on how handling defect-sparing. The Mount Rainier group ensures that CD-ROM's will be able to read Mount-Rainier disks though a generic read-driver, allowing read-back compatibility. This drive will be intergraded inside Windows OS (hence the Microsoft participation)...

2 K Addressing

With the current CD-RW format, a block-size of 64 kB is required when most data systems are based on 2k or 4k addressing capabilities. The Mount-Rainier group has solved this issue and adopted 2k logical addressing. This allows file-system and caching capabilities of the host to be transparent for the media related block-size.

Background Formatting

We all know that in order to use a packet writing software, the necessary formatting must be done. The Mt. Rainier format solves that <problem> also. After the disc is inserted to a CD-MRW drive, a background formatting will be done, invisible to end user. That minimizes the time which a user has to wait until the disc is ready for sure. The formatting is very quick (few seconds). The use-experience is optimized by ensuring that drag & drop data-storage tasks will get priority above progress of "de-icing" and "finalization" in the background by the drive.

Command Set

The Mt. Rainer group will add all commands and mode-pages in the MMC-3 standard.

Compatibility and Standardization

The Mount Rainier group main focus is to make sure that there will be no compatibility issues with existing and future drive. Also the need for vendor-related legacy support will be reduced.