Communication (Read Settings)
Read Settings
Retries
During reading, IsoBuster will typically (and where possible) read more than one block at a time. If that fails for some reason IsoBuster will read every block individually.
For both mechanisms a default retry count is set. You can change this per device using the sliders. This change only affects IsoBuster behavior, no other application (e.g. the OS itself) is affected ! This setting is not saved and next time when you start up IsoBuster the default setting will be used again.
In case reading takes very long, because there are many errors and the device needs a long time per block, you could consider to read with a lower retry count. If you notice that with more retries you don't find the data either it is rather safe to go to a lower retry count and it will save you a lot of time. On optical media (CD, DVD, BD) the drive may need 30 seconds or more per block in case of errors. I you multiply this delay with the amount of blocks on the disc, for instance 330,000 on CD or 2,200,000 on a single sided DVD then I don't need to make you a picture of what that can mean to your precious time. Luckily and mostly only a smaller part of the blocks is unreadable, hardly never will all data be too corrupt to read.
Since IsoBuster 4.7 it is possible to set Single block transfer retries to 0. This means that if a read, covering multiple blocks, fails, not every single block is retried.
Delays
Especially with older optical drives, in combination with certain (hard to read) discs, it is sometimes possible that when you select "retry" on a faulty read the data can be read anyway. This is a bit strange as IsoBuster does a number of retries internally anyway and the only explanation seems to be that the drive needs some time to "breath". E.g. the drive needs to cool down or spin down or there is a design flaw in hardware or embedded software that causes this behavior. So if you are in this situation, e.g. you're extracting data from a CD and each time you find yourself hitting retry after which the process continues normally, then this option is for you. By setting a number of seconds in this option, IsoBuster will wait that long each time before the read is retried. So the drive is allowed to spin down and correct whatever situation that causes this problem.
This option can cause a serious speed penalty, so use it only when you are sure it will help you !
Its behaviour can be further fine tuned by using /delay: on the command line (or via @cmdl:/delay:)
Additionally /chsp: may come in handy too
Read Reverse
When this option is checked, IsoBuster will reverse read an object during extraction. For instance when extracting a file, or image file (*.iso, *.img, *.ibp/ibq etc.). It does this using a range of blocks. For instance if the range is set to 1000, IsoBuster will sequentially read chunks of 1000 blocks, but start with the last chunk and work its way back to the beginning of the file. The resulting file will be identical to a normally read file, but the drive will have been stressed in a different way, to possibly work around unreadable areas etc. There are limitations. Reverse reading is ignored for all read processes that require a sequential read. For instance when decompressing NTFS files, when decompressing Roxio compressed UDF files, when extracting Video that is converted to MPG on the fly and while scanning an entire disc in search for missing files and folders, especially for the sake of files found based on their signature.