Thanks to an awesome blog post over at Biosrhythm, I now have RS232 serial communication to/from the Commodore 64.  I built what is essentially the exact same adapter that he used.  The only minor difference is mine is based on the MAX3232 chip.

So I wrote some code based around some code samples I found online.

Then I ran some serial communication tests to and from a PC, first inbound:

Then outbound (which will become important when sending data to the printer):

Worked like a champ, here’s a shot of the User Port to RS232 adapter:

I’ve also run the self-test on the receipt printer (which finally arrived at my doorstep today):

I also ran some serial communication to the printer via serial from my PC.  Just testing, and it seemed to work perfectly.

I’m “this close” to having this work, unfortunately I don’t have any Male DB9 connectors floating around and can’t find my stash of serial gender changers.  I’ll pick some up after work tomorrow and I should be up and running at that point.  Updates to follow.  🙂