See loadkeys(1), setleds(1), setmetamode(1) for the codes generated by the various keys and the setting of leds when not under X. Under X, see xmodmap(1).
See setterm(1), kbdrate(8) for properties such as foreground and background colors, screen blanking, character repeat rate when not under X. Under X, see xset(1), also for key click and bell volume.
The file /etc/termcap defines the escape sequences used by many programs
addressing the console (or any other terminal). A more modern version is
found in /usr/lib/terminfo. (See terminfo(5). Terminfo files are compiled
by the terminfo compiler /usr/lib/terminfo/tic, see tic(1).)
(On my machine) /dev/console is a symbolic link to /dev/tty0,
and the kernel regards /dev/tty0 as a synonym for the current VT.
XFree86 1.3 changes the owner of /dev/tty0, but does not reset this after
finishing. Thus, dumpkeys might fail because someone else owns /dev/tty0;
in such a case you might run X first.