Appendix III. Mini FAQ for MO drives

The following is based to a large extend on information provided by the relevant drive and disk manufacturers. It is included here purely for user convenience.

1. Why do MOs have a high resistance to dirt and scratches?

Data is written to and read from the recording layer of an MO disk through a thick polycarbonate substrate. The diameter of the laser beam is wide at the point where it strikes the disk surface, but becomes narrower towards the recording layer. Therefore, dust and scratches on the disk surface hardly affect the generated signals.

Even if the disk surface has a large piece of dust or a deep scratch that is likely to affect the signals, the employed"powerful" error correction scheme can reproduce the original signals correctly. Since the optical pickup DOS not come in contact with the disk and is separated from its surface by approximately 1mm, there is almost no chance that the disk surface will get scratched due to dust.

Moreover, remember that as in the case of DVD-RAM disks the disk is sealed into a case. Our experience suggests that 95% of all disk reading problems from disks that originally had no defects, comes from incorrect handling in part of the user!

2. Why are MOs unaffected by magnetic fields?

The recording layer of an MO disk is made by TbFeCo, a material that has extremely high coercivity. The MO drive projects a laser beam to heat up the magnetic substance to a temperature at which it loses its magnetism, and then starts writing data. MO disks can still record in the presence of weak magnetic fields, but not at normal room temperatures. Therefore, bringing a conventional magnet close to an MO disk at room temperature will not corrupt the data on the disk.

Possible MO operation problems

3. Scan Disk takes an extremely long time, and I had to cancel the operation. What do I do?

There is a possibility that physical or logical format information was corrupted when the formatting operation was interrupted. If the disk is in a state in which it can be formatted physically, use the formatter that came with your device driver to format the disk physically, then reformat it in MS-DOS format, and you should be able to use the disk again. Remember that if you format a disk, any data on it will be destroyed.

On Windows 95, an unformatted disk cannot be "quick formatted." Use "normal formatting."

4. I inserted a disk into the drive, but it is not recognized

Data on the disk is unreadable. Check that your disk is formatted. Alternatively, logical format information may be corrupted. Use commercial repair software to find out how severe the damage is, and repair it, accordingly.

Dirt on the disk or lens sometimes prevents the disk from being recognized.

5. Data cannot be written. Running ScanDisk or Norton utilities results in a "Defective clusters generated" message. What do I do?

First, make sure that the disk is not write-protected. The drive may not have enough recording power (due to dirt on the lens, laser deterioration, etc.) or the disk may be dirty.

6. Why can't 540 MB and 640 MB disks be used?

Check the manual of your drive and see if it is compatible with 540 MB or 640 MB disks. (If your disk is for 128 MB/230 MB size disks, 540 MB or 640 MB disks cannot be used.)

On a 640 MB disk, one sector holds 2,048 bytes. On 540 MB, 230 MB and 128 MB disks, one sector contains 512 bytes. To use a 640 MB disk on Windows 3.1 or MS-DOS, you need the proper device driver for 640 MB disks. Check with your dealer.

7. Why does my disk drive misidentify the inserted disk and hang up when I exchange a 128 MB/230 MB/540 MB disk with a 640 MB disk?

Exchanging a 128 MB/230 MB/540 MB disk (512 bytes per sector) with a 640 MB disk (2,048 bytes per sector) may sometimes cause this problem. Restart your computer before inserting a disk with a different sector size.

8. After I attempted to copy a file, I received a message saying "Too many files exist," and could not copy the file although there was enough free space. Why?

If an MO disk is formatted in Super-Floppy format, only 512 folders or files can be stored under the root directory. If you attempt to create any more folders or files, you receive this error message. Delete any unneeded files and create a new folder, then copy the new file to the folder. Drive supplier provides a device driver to avoid this problem. Install the device driver before you use a MO drive.

9. A DOS/V formatted disk cannot be accessed on Windows NT 4.0. Why?

Because Windows NT 4.0 has its own format, certain types of disks cannot be accessed. Use the disk administrator to allocate the areas and reformat the disk.

10. Disks used on Windows 95, Windows NT 3.1 or Windows 3.1 cannot be read on Windows NT 4.0. Why?

As described above, certain types of disks may be unreadable due to differences in format, even if the device drivers you are using can support these disks.

11. What are the advantages over competing formats? (ZIP)

• High capacity. MO (1.3GB) can store 5 pieces of Zip Media (250MB) data in a one media.
• Low media cost. Media cost of the Zip media is $0.06/MB, on the other hand MO is only $0.019/MB.
• Large range of capacities can accommodate a wide variety of applications.
• High compatibility.

12. Advantages over CD-R/RW

• Small disk size.
• High reliability.
• High transfer rate (not according to our tests anymore).
• No need for writing software.
• Windows 95/98 includes MO standard driver software.

10. Disadvantages over competing formats

To be completed based on actual user feedback we will receive:)