Hi Scott,
I looked at that a while ago. The 8255 would be a good chip to use for this, and from a hardware point of view it's fairly easy to do. However, I would struggle with making software drivers for it.
Also, I'm lucky enough that my dot matrix printer has Centronics, RS232 and USB connections, so it's not something that I need any time soon.
A couple of years ago, however, I did make a little adapter that allows a Sinclair ZX Printer (the little thermal printer) to be plugged in. Again, from a hardware side, it's fairly trivial to do. I can make dots on the paper as a proof of concept, but actually driving it to print anything useful is going to take some time to sort out.
Spencer