Quentin Barnes has updated his DMKCHK utility to v0.0.4
DMKBSC will parse a DMK and advise as to which specific sectors which are bad, if any. DMKBSC runs under LINUX, Rasperry Pi, Windows x32, Windows x64, and under MSDOS.
The new version fixes a few bugs in the reporting of the sectors.
A Tarball with binaries and with the source of v0.0.4 can be downloaded GITHUB (in tar.gz format), or from the DSK and DMK Image Utilities page on this site (which is in ZIP format and has the Source Code included).