I recommend to search for and find the manual for the Realism Patch 5 or 3. Not every detail may be matching with BMS, but all in all you get an idea, also on background and sensors. It were these manuals by the RP group that got deep into F4, more than anything else. But it is quite a read, though an exciting one. Back in those days, manuals of this size were unknown.
Do not give up too early, its worth it.
With DCS, system studying can become even "worse".
P.S.
https://sites.google.com/site/falcon4history/files
Superpak SP 3 or 4 should help, too.