Nowadays it's HALON ( aka Chloroflorocarbons bromides I think )
, same agent for Engine & Cargo hold. proc is like what u
described..still same.
Boeing has levers for pulling, Airbus system is press button type.
2 agent each, except for APU, only one bottle.
as u can see from pic here.
my 0.02chimes
oh btw, thanks for explaining what a NOOB is. haha..that's me
alright! (wink)