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Another dated bit is hiding under the plastic cover - a modem! The Australian PSTN is supposed to be retired this year but in most residential areas it's been gone for years.

This modem chipset is kind of cool, it's a Si2400 "ISOmodem". The idea is that this replaces the traditional big expensive isolation transformer with a pair of high-voltage capacitors, providing an isolated data (and possibly power) link to a second chip on the line side which handles the analog business. Neat!