Besides, MiNT supports threads, so one might consider putting IO to threads also on MiNT. Just note that MiNT thread stack is much more seriously constrained than on systems with virtual memory, it has some additional gotchas (see "pthreads" ml-thread in 2011) and I don't know how thread safe MiNTlib functions are (starting from malloc).
Because portable-threads (pth) for MiNT are not concurrent, there is no thread-safety problem with MiNTLib.When you have real conccurent threads, you HAVE problems with malloc() and free().
And maybe also filehandles, sockets, etc. So it's better to not do anything which calls mintlib in an thread - without wrapping it around in an critical section.You maybe also interested in this page, which I have put online a few month ago:
http://freeshell.de/~monokrom/geeklog/staticpages/index.php?page=mintthreadI know, it's very rough and spare on informations - I should change that ;)