Thanks for your reply. I uninstalled the printer, and started up the installation, disabling the firewall first (a suggestion from another forum).
If I chose "personal installation--install for use on this computer," it would not let me past the "connect the USB cable" page without a cable detected. I simply had to bail.
If I chose "network installation--install for use on a network," I ended up at a (blank) page to assign a port name. The printer wasn't detected automatically, but I could go in through "manual add" and select a peer-to-peer client, since the printer is connected to another computer. I enter the other computer name, and the printer's share name (with "allow communication through the firewall" check-marked). It works for a while, then comes back to the previous page, showing port name (now with the printer listed and highlighted), but no IP address or MAC. Clicking NEXT starts up the install, which finishes and simply closes. But the printer now shows up in my printer list as the default printer, in a READY state.
I performed #4-8, but the printer is already listed with a port, so I get an "already exists" message when I try the add. I tried to delete the port, but get a "resource in use" message, so it can't. I tried "configure," but am told there's nothing to configure. Bidirectional support is (was originally) checked, but still no communication.
<sigh>
