Another post asking for help determining the number of zones

Hi all,

I'd appreciate it if someone could help me figure out how many zones my old system has.  I did some research and found the user manual of the system but I've been unable to figure it the number of zones and how these are wired. My system also has a number of small white boxes (pictured attached) that I do not know what they do. I was able to trace some of the cables, pictures attached, but I could not determine how the zones are wired and what certain cables are for.

Thanks in advance!