hardware - audio aux in vs mic

[Lars Noodén]

Can the mic port be safely used for audio in or must I stay with the
machine with aux in?

I will probably be digitizing some analog audio cassette tapes early
next year.  I have an old ghettoblaster with a 3.5mm jack that can play
the tapes and a choice of two computers.  One has what appears to be aux
in the other has a microphone port, both 3.5mm.  I wonder what is the
safe way to connect them.

Regards,
/Lars