A client, one probably best described as a serial entrepreneur, was clearing out their office. Part of this included a bunch of old electronics and like a good engineer with more space than sense I said I will take it off your hands. I now have a bunch of printers to rip apart (they often have very nice metal rods and gears buried in them that are suitable for all sorts of projects) and/or fix. However an unexpected part of that was a whole bunch of lower end business oriented phones. Normally I would pull them apart, strip the components or use them for soldering practice (much like teaching someone explosions works for teaching chemistry I find teaching people to bug phones the old school way works pretty well for teaching soldering and analogue electronics), however I have pulled apart loads of phones and similar devices over the years and they seldom have terribly interesting/rare/high quality components. All my clients have long since gone digital and/or VOIP as well, or if they do have analogue it is an all singing, all dancing setup to span a building. To that end I thought that is enough phones to do something silly with. The problem comes in that my knowledge of analogue phone systems is rather limited -- phreaking probably died in the UK in the very early 90's and where I was at that point in time (BT, the then dominant telco, had some serious research going on there and then) it was likely dead before that, not that I would have been able to do much as I was just getting the hang of dos and windows 2 through 3.11 back then. To that end suggestions for projects, devices, resources of info and software are all requested and welcome. I have yet to go back and fill that hole in my knowledge, what I have beyond reading the manual ( http://xkcd.com/627/ is entirely correct), plugging the thing in, redoing a connector/box/wire would not make a good anecdote. However a while back I saw a video on turning a raspberry pi into an asterisk pbx. Likewise I do enjoy phone phreaking presentations, the following providing most of my knowledge of matters here Apologies for the photo quality; I neglected to charge my normal camera and had to use my video one. If model numbers are necessary then I will type them out. Likewise if one there happens to be something a legacy system (or legacy person) of yours does well with then speak up and it might be spared its fate. I am happy enough to spend a bit to see what can be done here (the various things that rasp pi video referenced being good) and I also have a whole bunch of modems that I also normally use for soldering (and winding up a guy located somewhere in Taiwan where modems are apparently still a thing).