Does anyone know what CSDB is and where I can get some information on it.  Max 
Technologies has a card out but I can't find anything more along the lines of 
the parameters with which it operates.  I have found things like... COMMON 
SOURCE DATA BUS.... COMPUTER STANDARD DATA BUS.... COMPUTER SOURCE DATA BUS... 
and some others that I forgot at this point.  It works with serial data 
transfer between the aircraft and some instruments and other avionic devices.  
Looking at the connector on the card, it resembles RS422, pin 1 = ground, pin 
4 = RX Hi, pin 5 = RX Low, Pin 8 = TX High and Pin 9 = TX Low.  I might have 
the RX and TX groupings flip-floped but thats as much as I can find out.  I 
believe its RS
422 and am going to work accordingly but if anyone knows 
anything about it, I would really appreciate it if they would tell me what, 
exactly it is.
Thanks
Kenny