This is for information :

If someone is interested in developing a dedicated controller that can be connected to the CS1 in the way a MS1 would be connected, that is, trough the CAN bus, I may send him some potentially useful computer code.

This is no trivial task since unlike for the CS2, there is no "official" documentation about the protocol that the CS1 is using to communicate with devices on its CAN bus - that is : Mobile Stations 1.

I used parts of the project called Railuino ( https://code.google.com/p/railuino/ ) to connect an Arduino ( http://arduino.cc ) to a Märklin CS1R, ie. the "reloaded" version with ESU ECoS Software 4.0.0.

The key difference here is that it connects to a CS1R while Railuino is written for connecting a kind of MS2-subsitute to a track box. I do not know if someone worked on connecting a custom device to the CS2 trough the CAN bus, but connecting to the CS1R is a challenge due to the limited documentation and the need to exchange specific data to "register" the custom device in the CS1R.

This is experimental and poorly coded at present, but thanks to some very useful documentation found on the web
( http://www.skrauss.de/modellbahn/mdigital.html ) it works sufficiently well to prove that there is no critical difficulty. I could "register" the Arduino as a "Mobile station" in the CS1R's list of connected devices and send a command to a locomotive.
I have no commercial intention and little time to further work on this, but if I can spent enough time, my first objective is to create a dedicated control device for a Marklin gantry crane. Other potential uses would be to develop locomotive controllers that are more "realistic" or "convenient" than the MS1.

I think that the code will remain quite rough if it is only for my own use, but maybe some efforts could be done to build a cleaner version if others express some interest in this.