I got a CD/Radio unit from a late model S-Type and decided to peek inside. A few photos of the effort:

http://cid-929c26e96a635de1.skydrive...%20Jag%20Radio

The main CPU is Fujitsu MB90F574/A flash based 16 bit microcontroller. The audio DSP is SAA77064. The tuner frontend is SAA6588TV. The optical unit is made by Apline.

The D2B interface IC is a mystery has label 2440 OS8101. I could not find any documentation about it, except it is also used in some Benz units. Supposedly ST micro still manufactures the clip, but has no info whatsoever.

I'll try to peek in the CPU software to see if I can learn more about the D2B bus.

 

Nice job. Gives the appreciation for what goes into these radios.

 

I opened mine up as well, but it was to change the leds.

 

does the early s type have changeable LEDs

 

Depends, what you mean by changeable. Defenitely there are no sockets, you need a soldering iron to remove the old ones and sloder new ones in place.