"Rectifier cells"=diodes.
And they are still using a matrix.
Possibly the matrix layout and diodes have been shifted off of the membrane to a circuit placed between the membrane and main controller. But that would mean the membranes would need two dedicated traces for every single switch. It's possible, but rather impractical, and it mostly defeats the whole point of using a matrix (cutting down the number of signal lines needed.)
I'm not sure if they have done it properly with brute force, or botched the design. I need convincing this is truly NKRO.
