The Buzz and Chatter of Busy Motherboards

This  paper on acoustic sideband decryption attacks reminds me of working on my old 8088 and 286 systems. I've always liked ambient music, and pre-WinAmp, that was supplied by a battered boombox tuned to any of the available FM rock and roll stations. One of my favorite stations was on a frequnecy that was favored by the computers radio-noise; it would override a stastion with a chatter and rumble that was quite distinctive. I could hear RAM acesses as quite distinctive tones.

The interesting part, now that I think about it, was that a system with a clock speed of 4.77 Mhz was generating radio interference somewhere between 98 and 104 Mhz - all my favorite radio stations lying in that bandwidth. Perhaps it was actually being picked up by the radio circuitry after demodulation, as a amplitude-modulated wave affecting a poorly shielded amplifier circuit?

The more I think about it, the more curious I become. I have a box of 8088 motherboards tucked away, I wonder if I have all the other parts around to get one up and running? It would only have to boot, to run some basic tests - the POST RAM check should demonstrate the interference.

No comments:

Post a Comment