I figured out what happened here when I reloaded Linux and it happened again.
I have 2 identical drives that I performed a
dd if=/dev/hda of=/dev/hdb
command to clone my HD to my 2nd HD. Everything worked OK until I rebooted and that happened, again.
Nothing in the console window but a black square that appeared to be the prompt, only I couldn't do anything with it.
Instead of reloading again, I simply removed the 2nd drive and all is back to normal. It has something to do with loading Linux with 2 HDs that both have a boot sector, I guess. It recognised the error, on boot, but loaded normally, except I can't use the console - which puts me dead in the water for all admin purposes.
I don't have a backup tape, and I like the DD command better than dumping partitions onto the 2nd HD because I can have a bootable HD in case of recovery issues.
Any idea how to get around this?