Just found old m240 Its working OK but do not know how to change music Do I need software.
Here is the User’s Manual for it, but there is no firmware posted anywhere here. If I recall correctly, this antique had like 4 hardware versions and therefore 4 different firmware versions for it. It’s so old SanDisk doesn’t support it anymore with firmware downloads.
On the plus side though, it uses a AAA battery so you don’t have to worry about running out of juice and not beinig anywhere to re-charge it.
Good luck with it!