This is sort of a follow-up to my previous post which talked about how you can use the split command in Linux to create split files which can be joined with hjsplit on Windows. My theory is that hjsplit does the same thing split does - which is just take the file and split it into the required number of pieces. No special headers or padding or compression or stuff. If that's true, it should be easy as a pie to join the files split with hjsplit
To join files split with split, what I would do is use cat. Like this : | $cat xaa xab xac xad xae > debian-testing-i386-DVD-1.iso
Here xaa, xab, xac, xad and xae are the split files and debian-testing-i386-DVD-1.iso is the file after the join. I believe this should work fine for split files got from hjsplit too. Since I'm too lazy to go try it out in my friend's Windows machine, I'll leave it here at that. Do let me know if anyone's tried it :)