ManageDsk is a small tool which allows :
- Create a empty .DSK file (in DATA format),
- Add some files in an existing .DSK file,
- Extract some files from an existing .DSK file,
- Rename some files contained in a .DSK file,
- Delete some files contained in a .DSK file,
- And since version 0.15, Read/Write DSK files from/to a 3,5" floppy
You can find it here : Amstradeus
In the download section : Download
Sid made a port of ManageDSK to Linux, Mac Os X and other UNIX OS. This port is command-line only but features all the important functionnalities for managing DSK files. You can download it at homepage.
This tool works on all unix platforms, unlike cpcfs/cpcxfs which suffers from many endianness problems and can't work on powerPC, for example. The command line interface is designed for easy integration in a makefile, making it more efficient for cross-development.
You will probably want to use dsktools to write the dsk image to a real floppy.