Kick Assembler Manual
Chapter 11. PRG files and D64 Disks

A custom disk writer is written in a plug in. Refer to the "3rd Party Java plugins" if you want to implement one yourself.

It is called like this:

.plugin "myplugins.Mydiskwriter"

.disk MyDiskWriter [.. disk params...] 
{
        [ ..file params.., segments="Code,Data"],
        [ ..file params.., prgFiles="data/music.prg"],
}