The guys from Tomorrow’s World can tell you about Toasty more succinctly than me:
Toasty was built around a TINI chip from Dallas semiconductors, in the days before arduino and raspberry Pi. It was ahead of it’s time though with a Java OS and built in ssh access. Its IO was similar to the arduino and controlled a modem chip that made the little beeps and whirrs that went down the phoneline to ask the server what the weather was like. It then used electormagnets to turn switches on and off. All very low tech by todays standard where everyone would expect it to be airplay enabled by default.