The company I work for bought a Telrad Digital Key BX system a while back and had it upgraded a couple of years ago to accomodate some growth. I recently started working for the company, but as a computer/electronics technician. And now that the person who knew something about the phone system is gone, they want me to support it, without any training or prior experience on any phone system. One of the first things they want me to do is to hook the system back up to the buildings paging system (it was hooked up to it at some time in the past) so they production floor can hear when someone's being paged for a call.

Could someone please help me identify what I have here, and maybe a good place to get a manual for a reasonable price, and any other advice that might help me out.

Here's the card layout and their colors from slot 1 to 6 (left to right):

MPD CHL OCD ELD EHD open
orange blue yellow green green

The PC connected to it is running SBS system version 5.50E and handwritten on the Telrad unit is SB7.20.

what cartridges do you have on the OCD?
And do you have the programming software to make changes?

As far as I can tell there is only one cartridge in module 1 slot. It has a red LED and an RCA jack. Could that possibly be an analog audio out? I hadn't looked that closely since everything is always on and being used.
I doubt that there is any software around for that. I've looked around and haven't found anything that looks like it. Though I don't know exactly what I'm looking for.

I could send you the book free of charge. Just e-mail me. [email protected]

Wow. Thanks a lot. You guys are awesome!