Okay, I think I found it. (Great answer, BTW; wow, pics and everything.) Hah, I should have known - just look for the cable plugged into the wall, follow it to the computer, unhook and reconnect to the computer. Shoulda been obvious.
However, I hooked up the cable to my laptop and sent a document to my printer. Nothing printed. I didn't see an error message indicating a problem so I expected the doc to print, but it hasn't. Do I have to install a printer driver for my computer? Probably I do. Can I find that on-line somewhere? It's an IBM Workcentre M20i.