Gee, I've had our Hold buttons wired up for a "Ringer Tie ON" indicator for 30+ years - Dad worked out of the house (since retired). And as the Official Resident Kid (we moved here when I was 10, and I started putting the system together at about 12!) I didn't want to get woke up by his calls, and vice versa.
But there were times we had to cover each other's calls - No Problem with the wonders of the 1A2 KSU...
One 12VDC dual-coil latching relay, two homemade bridge rectifiers, hook the coils to the Melco KC-19 intercom on BZ 28 and 29, and tie CA for L1 and L2 (their lines) to the CA for L3 and L4 (my lines) together. And a second set of contacts to light all the HOLD buttons. Bada-Bing!
I had to go back and redo the first few cable punch-downs - I didn't quite grok how the Color Code went, and when I got into the Uncharted Territory of the yellow and violet binders, it went random. Then I got a job in the Switchroom and went "Oops!"
But now that Dad's starting to graduate from normal "CRS" to Alzheimers (Yeah, I'm really looking forward to that... :bang: ) I'm going to have to build a diode matrix instead so I can catch the House Line at night - and yes, I printed out the Diode Matrix thread. I have other long-delayed mods to do, you'll see me around.
I've been waiting for that second-hand WE Shoebox to die, but it won't. Put in some WE 400G cards when Canoga Park went from Crossbar to ESS, still going...
--<< Bruce >>--