There are four "layers" to the IMSAI panel.
More accurately, there are five layers, the four I just described, with the 5th one
being the circuit board with LEDs and switches mounted etc.
Regards.
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools:
www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html