Pointless Fun Hacks: Transfer Files Using Your Soundcard

Some ubergeek named Viktor Lofgren devised a way of transfering files between computers using soundcards and noises, following the basic principles used for modems. All you need are two soundcard-equipped computers, speakers and a microphone.

According to CrunchGear, the same pulses and blips used in modems can be recreated on your computer, and sent to another using the speaker and microphone. Lofgren laid out the basic rules for soundcard file transfers, which includes translating to binary code to noise and back, as follows:

For every character:
For every bit:
Send a short pulse if the bit is 1.
Send a long pulse if the bit is 0.
Send a silence.
Send a very long pulse (4 times as long as the shortest pulse).
Send a silence.

After that, its just a matter playing the noises out a speaker, with goes into a microphone rigged to sit against it, and that mic transfers the sound to the other computer. But then there's the matter of converting the noise back into 1s and 0s, which is a slightly more involved. Luckily, Lofgren lays out the whole thing on his blog which you can read here. [Awesome Geek Blog via CrunchGear]