This was the first of the boards, it was at the top of a stack of boards. identifiably the master board.
the lable "CPU" gives it away. as a note, the plastic tabs on the end were all facing out, the CPU was red, a bank of eight were green, and there was a blue one.
Yeah about that backplane.. they all drop onto a backplane full of connectors like that, kinda like an old XT system
they do pop out of their sockets, still haven't been able to identify what kind of chips they are
Curious here is the six full-width RAM chips, and the quarter-width "RAM0" chip. Also note the battery connector.
I peeled the sticker on the bottom ROM chip off. ROM3 slot was empty when I found it. Also there's the battery. Unfortunate story around these ROM chips ...
this is the second board, there were seven or so others like this
There were two blocks of these... things. I'm assuming it has something to do with control of phone circuitry, honestly I don't know.
The other label. This was the green card type deal.
The ribbon cable plugged into the unit proper (the entire PBX was about four feet tall)
standard style backplane.
So that was that. Kinda humdrum hardware, but oh well.
the sad part is, josh then realized that Frys sold EPROM readers and burners. when we got there, he had forgotten for how much they sold them for, and josh and cashan got me out of there before I spent another ~$1K on stuff for analysis of hardware pulled out of an eight year old PBX.