[s-cars] Question(s) for long term Audi turbo people

[David Forgie]

I am working on a project wherein I am documenting the development of the 20 Valve turbo RS2 ADU engine starting with the first Audi inline 4, the Mercedes-designed Audi F103 Aka Audi 
72 (72 PS) engine, through the development of the Dr. Franz Hauk-designed Audi 80 engine, the EA827 which also became the first Golf engine. I have not gone through the development of the EA828 inline five and have just started the development of that engine into the first Audi turbo inline five. Where I need and will need help is information how the turbo systems were 
controlled. I understand that the first boost control was all mechanical but there was a fueling computer (But I don't know any part numbers, manufactures, etc). I know the mid-1980's 
turbos had Hitachi ECUs but even then I don't know much about them (other than there was a resistor trick to boost fueling). 

Any help, pointers to info would be greatfully appreciated. 

Dave F.