The disk imager is a member of the SPS suite of preservation technologies.
It is a (currently Amiga-only) tool that samples a disk and gets what is on the surface “bit-for-bit”, which is quite unlike what you get by normally reading though the FDC (Floppy Disk Controller) due to its data-changing effects. It does this using extremely precise timing, specialised algorithms and digital signal processing.
The tool is command line based, and is surrounded by scripts to make dumping easier. This is all contained on the “dumping disk” which people are sent when they contact us about preserving their collection.
The “raw” images produced by this tool need to be put through the analysation process before they can be used.