04-08-2014, 11:27 AM
Starting with v1.08 software, there is the option to convert an Amiga disk into a ADF (.adf) image file.
During the conversion, there is a recovery process that occurs. After 10 reads with not finding 100% good of the sectors, the head is re-seeked to zero. This clears debris from the head if it there is any that might be stuck under it. Also, the MFM decoder variables are widened to make the data separator exceed the normal limits. This can occur up to 9 times (99 retries) before giving up. Setting the number of retries higher gives you a better chance of recovering bad sectors. The default is 50.
The display shows the current status of the image process. GREEN blocks are tracks where all of the sectors checksum'd and converted perfectly. YELLOW blocks are tracks where at least 1 sector checksum'd and was converted correctly. RED blocks are tracks that contain absolutely no valid sectors. Prior to starting the imaging process the image file is filled with all zero's ($00). Sectors are decoded into the buffer whether they checksum or not. So, it is possible that all or partial sector data will be recovered whether the data block checksums correctly or not.
You can remove the disk while the image process is occurring, throw in a disk head cleaner for a few seconds, remove it, and put the original disk back in again. This does not interrupt the imaging process, and I found that this works really well with disks that are really dirty. As the disk spins, the surface debris immediately starts collecting on the head and that really needs to be cleaned to have a good read. I have disks that grind and squeal that I have been able to successfully image perfectly - and they won't load at all on an Amiga!
During the conversion, there is a recovery process that occurs. After 10 reads with not finding 100% good of the sectors, the head is re-seeked to zero. This clears debris from the head if it there is any that might be stuck under it. Also, the MFM decoder variables are widened to make the data separator exceed the normal limits. This can occur up to 9 times (99 retries) before giving up. Setting the number of retries higher gives you a better chance of recovering bad sectors. The default is 50.
The display shows the current status of the image process. GREEN blocks are tracks where all of the sectors checksum'd and converted perfectly. YELLOW blocks are tracks where at least 1 sector checksum'd and was converted correctly. RED blocks are tracks that contain absolutely no valid sectors. Prior to starting the imaging process the image file is filled with all zero's ($00). Sectors are decoded into the buffer whether they checksum or not. So, it is possible that all or partial sector data will be recovered whether the data block checksums correctly or not.
You can remove the disk while the image process is occurring, throw in a disk head cleaner for a few seconds, remove it, and put the original disk back in again. This does not interrupt the imaging process, and I found that this works really well with disks that are really dirty. As the disk spins, the surface debris immediately starts collecting on the head and that really needs to be cleaned to have a good read. I have disks that grind and squeal that I have been able to successfully image perfectly - and they won't load at all on an Amiga!