Thanks to all who found/offered a PCI graphics card. My problem has been solved, even though it hasn't been really understood. A friend found a card of unknown condition, and I tried it. As expected, the motherboard graphics became inactive when I booted with the PCI card. However, the PCI card didn't work either. (It's that "unknown condition" thing, I think.) After a couple of power cycles, I removed the PCI card, and, magically, the motherboard graphics began to work. I don't see anything new in the X config, so I can only think that the system reset the motherboard graphics card back to a functional state. If anyone has a better theory, I'd like to hear it. Thanks to all who responded with an offer of a graphics card. Thanks, Bill