Install from .iso Fails

[Thomas D. Dean]

I tried to install FreeBSD and failed.

I downloaded FreeBSD-12.0-RELEASE-amd64-bootonly.iso, burned a CD, and 
booted.

The boot sequence did not complete.  It was in a loop
...
xchi resetting the controller
...
xchi resetting the controller

I could get to the ptty that was logged in as root.  ps -ax seemed OK.

I think I had FreeBSD on this machine several years ago.

Motherboard ASUS P9X79 PRO
Intel(R) Core(TM) i7-3930K CPU

Any ideas?

Tom Dean