Update. IT WORKS!!!
It was a hardware problem after all. I finally unplugged the connector on the back of the printer and plugged it back in again, and DANG, she printed. I never suspected this, because as I had related earlier, I was able to plug my laptop up to it and it printed fine. Very strange, but it's an older printer and maybe like old folks, it's arthritic and the weather affects it, like bad knees or something. (Seriously, the connecter probably hasn't been off in probably 10 years and there might have been a tiny amount of corrosion present.) Anyway, problem solved and lesson learned: check the really basic stuff right at the outset.
Thanks again. I've been reading some of the other forum items to educate myself and it's obvious that you folks really try hard. Scott