Simulated telephone

On 8/24/10, Richard <legalize at xmission.com> wrote: If you mean as an enhancement to the COMBOX, that might be pretty cool. I don't relish trying to hammer on the 8048 code - it was written by a hardware engineer and has zero comments, zero vertical formatting, and has tests followed by branches two and three code pages later. The listing resembles the output of an automated non-symbolic code disassembler (the same guy wrote the firmware for our Qbus product - I had to re-write most of the structure for the firmware for our VAX-BI card). If you mean as a controller for a home-CO, I don't see the application. If you need a powered loop (depending on the age of the gear attached to it), you need enough DC voltage (up to 48VDC) to make the two devices think they are attached to the POTS network. When we were kids, that was a lantern battery to make a couple of analog phones work for talking, for example. If the receiving device won't connect without a ring (I've seen modems and such that needed ring voltage to latch relays, but many devices can just be put in "ANSWER" mode), that's another animal entirely. You can probably get away with 120VAC @ 60Hz, but officially, ISTR, it's more like 90VAC @ 20Hz. That part should only matter if you are trying to get a mechanical bell ringer to sound. An arduino won't help with establishing a DC voltage, nor synthesizing an AC voltage (at least not in any way that couldn't replaced by a 555 timer) -ethan