Apple's Disk II could control drive head motion in increments of 1/4 track, which made it possible for it to ensure that there could be no residual data between tracks, and I think some other drives like the Commodore allowed for half-track increments. PC drives and others that control the stepper motor using up/down pulses rather than motor phases, however,...
You can use loaddskf and savedskf on a modern computer. If you have an emulated floppy disk, you can unpack and pack diskettes to/from that. Note however, that these are bound applications, and it is best to open a command.com or 4dos session here.
For example, I use vfd.exe etc, to create a drive b:
loaddskf %1 b:
savedskf b: %2 /d /a
You then set b: to ...
Thanks for the above comments/suggestions.
This in the .cfg file works to allow reading 'sector 0' :-
mount c c:\users\roopy\source
mount -t floppy b: c:\Users\roopy\Downloads\BackupDownloads\iso\DOS5and6
imgmount a -t floppy Dos5.img
It means the code I'm testing can be run as a DOS command (temporarily) and it reads the boot sector from the ...
DOSBox only allows absolute sector reads from disk images, as mounted by IMGMOUNT.
You can’t use interrupt 0x13, service 0x02 on drives mounted with MOUNT. (To understand that link, note that imageDiskList in DOSBox is only populated by the BOOT and IMGMOUNT commands, not by MOUNT.)
The workaround is to use IMGMOUNT:
imgmount -t floppy a /path/to/floppy.img