I changed the display card setting from "Generic VGA" to "ATI Mach64".
This seemed to be the closest match.
The card is actually "ATI Mach 64 GX".
Anyway, now X will not start.
How do I change it back to "Generic VGA"?
From the virtual terminal I used "setup" to do "X Configuration".
But that did not work either.
It flashes some error messages and returns to the "setup" menu.