ADM mixing desk question

[alexxxchange]

I recently bought an old ADM mixing desk that I suspect was used for broadcast.
there don't seem to be any line ins or direct outs on it

I know that all the ADM stuff was made custom for different facilities but maybe this will sound familliar to someone or you can offer an educated guess...

-It is an 8 channel desk with 4 outs and two sub mix/monitor groups

-there are 4 parallel/switchable mic ins for each channel connnected via 25 pin connectors

-there is another 25 pin connector that says "Opto-in 1-8"
any body know what this might be?
8 line ins?... 8 direct outs to a compressor?.....

I'm trying to put off taking it apart. as I don't wan't to F it up too bad
I'll post some pictures tomorrow
thanks
-Alex

[Phalaris]

I'd check over at www.gearslutz.com last I saw there was a guy over there that had worked at ADM in design or something. I have some ADM 700 series mic/line pre plus EQ modules however I have no faders for them.