Solved
I was finally able to access my Mac after acquiring a wired keyboard, using a bootable USB memory stick while in the start up manager mode.
Almost immediately I received a notification that a new version of Little Snitch, a network app for OS X which allows or denies outgoing and...
24" iMac mid 2007 6GB RAM 1TB HD El Capitan OS
When starting up this machine I get this message:
"Your computer restarted because of a problem. Touch any key..."
Then in the upper left corner of the screen I get a message (in monochrome, like at the root level):
"CPU (1caller) process 1 s/bin...