I have made some .efe files on my computer, that are around 6MB's of size. EPSdisk seems to only work with floppies. So do you know a program that could write .efe files on zip disks? If it would work in XP, that would be a great bonus, but not a necessity.
Try Chickensys "translator free". It creates images of ASR filesystems. The free version is limited to a single instrument of unlimited size (I suppose).
You will have to find a way to put the created image on your ZIP disk. I would try this on Linux with utility "dd", no idea how to do this on Window$. Perhaps the translator includes this feature.