>unfortunately the modules I have don't use the original IFF format :(
>They start with the instrument names, and I haven't the slightest idea
>how a program like DirOpus or Diskmaster can see it's a module.

Modules aren't so hard - but they are not IFF.

Read in the first 1084 bytes of the file.  Now, check the longword at 1080.
It should read 'M.K.' for a standard 31 instrument module, or 'M!K!' for a
100 pattern module (rare).