Communication (Read Remapping)
Read Remapping Settings
Certain CD formats expect the CD reader to convert logical addresses to physical addresses on the media (this is called remapping). E.g. suppose a directory field says file_X is located at address x then an application (e.g. Windows) will issue a read command to address x to read the file. However, address x may in fact be located at physical address y. The CD reading device must take this in account and fetch the data from physical address y.
A good example of such discs are (with fixed packets) formatted CD-RW discs. E.g. the discs formatted by Direct CD, InCD, DLA, Drag to disc etc. These discs require Method 2 remapping by the CD Reader.
If you buy a CD reader these days then this drive is perfectly aware of this type of CD-RW and will do the conversion always. There are however OLD CD-ROM drives out there that can read from CD-RW (can deal with the different reflectivity) but are not aware of the physical formats that were defined for CD-RW. These drives will screw up your data because you will get data from wrong sectors/blocks/addresses. Often reading from these CD-RW discs also works really bad on these drives because they try to read sectors that are not meant to be read which causes spin downs and read errors and what more.
IsoBuster tries to detect these situations and will do the internal remapping that the drive is supposed to do. This is fully automatic and is based on special media-drive tests that are implemented. It does remain difficult to detect this always, the reader is not always cooperative in the sense that detection commands return incorrect information and so on. You should only try switching the Method 2 option if you have an older CD-ROM drive (All writers will do it OK) and a when you are trying to read a formatted CD-RW disc on which the file and directory layout seen by IsoBuster is looking weird and all file content is wrong.
A much newer standard is the Mount Rainier or MRW standard which has also been defined for rewritable media. On top of Method 2 remapping, this standard requires Method 3 remapping. Again this remapping needs to be done by the drive. So a Mount Rainier drive will do the remapping automatically, unless the disc is damaged and the drive gets confused. There are however millions of CD-RW and Method 2 capable drives out there that do not know of this relatively new standard. There are also not too many of these discs going around so at least that's not too worrying. Anyway, IsoBuster can detect Mount Rainier discs (with most drives, preferably writers) and will do the Mount Rainier remapping (or Method 3 remapping) if the drive is not capable to do it. IsoBuster will even do this on drives that are not Method 2 capable, so both the Method 2 and Method 3 remapping are done at the same time then. You should only try switching the Method 3 option if you have an 'older' writer and a when you are trying to read a formatted Mount Rainier CD-RW or DVD+RW disc on which the file and directory layout seen by IsoBuster is looking weird and all file content is wrong.