As I've got it, Lenz developed both protocols for Märklin; "Motorola" first, which got it's name from 4 Motorola chips that was used for encoding and decoding the track protocol. The coded signal was intended for IR remote controls by Motorola, if I've got it right. Later these chips have been replaced by special chips with more on it, also for the Motorola units; and the so called Motorola II has nothing to do with Motorola except it's compatibility.

After that, Lenz developed 2R protocol for Märklin too, which among others is symmetric which Motorola wasn't. I think original 6020 has Motorola encoder chip inside, but 6027 can't possibly have the same.

What happened next was that Lenz and NMRA combined and issued DCC, which I think is the same protocol as Märklin 2R (I mix up Märklin 2R and Märklin 1, I know) but as DCC is a standard, there were additional specifications added. Therefore, it's no guarrantee that the equpments work together, but AFAIK a chance.

One particular peculiarity I happenen to have some experience with, is the Lenz brake signal. With (later) Motorola decoders, if they sence a negative DC signal, the brake gently, with light and sound on. When DCC was decided, it was stated that a running train sensed a DC signal, which if interpreted "analog" should mean that it should reverse, would not cause reversing but a stop. This statement allowed for Lenz to keep their brake signal, and european manufacturers followed. It seems, other decoders makers let the train stop abrupt, without sound nor light. For this reason, it's possible on my layout to run multiprotocol Motorola+DCC, using DC signal as standard brake indication, because I choose european decoders!

/Lars

6027 can be seen as the "mother of DCC", since Lenz developed it and later proposed the track protocol to NMRA as a standard (as usual after some patent quarrels with M, regarding some features in the Motorola decoders...)...

The 6027 & 6032 can only use DCC bitwise register programming as I understand - this was before CV bytes were invented...