Looks like there are some people working on it - https://www.retroprinter.com/ This one is a raspberry pi one so far emulates text, ESCP, ESC/P2, PCL, PostScript, has a Centronics connector - which is a start (Mac serial would be nice)
Also see print capture devices which can intercept/log printer output (for data conversion/preservation) http://www.photologic.ca/cap.html
Also see print capture devices which can intercept/log printer output (for data conversion/preservation) http://www.photologic.ca/cap.html
Going to have to look into this more :-D