It actually looks like TC1 is essentially unused on Due (the PWM pins that COULD be driven are either not present, or are connected to the PWM controller or DAC (which are used in preference.)
and how is this about the Zero or Teensys?
Not really. The SAM3X chip has a lot of features such as a built-in real-time-clock and direct-access memory which aren't used on the Due. Some of those are design decisions that are frozen in the hardware and some of those are just because nobody has written the software for it yet....The hardware can do it but nobody has published the code.
Because there's no Arduino people except volunteers who publish stuff for others to use. If you want to write a tone() function for the Due, your name can be included in the contributors list.
I don't think it's so difficult to fix.If it uses TC1 (TC3, TC4 or TC5) they have no output pins. But then you should simply change the library to use other timer: TC0 (TC0-TC2) or TC2 (TC6-TC8).Note: Due has 3 triple channel timers. Unfortunately, TCx can refer to physical timer or 'subtimers'.You can see explanations here: https://translate.google.es/translate?hl=es&sl=auto&tl=en&u=https%3A%2F%2Fwww.foroelectro.net%2Felectronica-digital-microcontroladores-f8%2Ftimers-en-arduino-due-sam-t195.htmlSeems that you cannot see CODE blocks with google Translate, and they contains interesting info and code, so you'll need to check it in spanish: https://www.foroelectro.net/electronica-digital-microcontroladores-f8/timers-en-arduino-due-sam-t195.htmlI dont's know Due timers more deeply than exposed, but don't hesitate to ask if you have any translation problem.
I personally can't do it because timers and "real" C++ library code (apart from the simplified Arduino API code) are far beyond my skills, and actually I don't have urgent need currently for tone() on the Due (but perhaps some day in the future).But as you stated that it's not so difficult to fix, I (and probably many other users additionally) would appreciate very much if you did this fix!
I've looked at it, but it's way too complicated and I have no time right now to do it.
now wait ...now you state that it's even way too complicated for yourself??I already stated that writing C++ libs is far beyond my skills, so I can't do this task, there must be more advanced programmers to do that. But as already MorganS and westfw suggested it's not supposed to be that trivial eventually (and if it actually was, it probably already had been done since a long long time ago).So I'm still curious if one will take pity on that thing....