Back again in the early times of the dwelling laptop revolution, info was commonly saved on tape. Even greater, these tapes would make an almighty racket if you played them on a stereo, for the reason that the details was stored in an audio structure. The Basic Common Modem from [Anders Nielsen] is crafted to perform in a identical way, turning information into audio and vice versa.
The project is composed of a circuit for modulating data into audio, and demodulating audio back again into data. It is “universal” simply because [Anders] has designed it to be as format-agnostic as attainable. It doesn’t matter irrespective of whether you want to keep data on a digital voice recorder, a cassette deck, or an aged reel-to-reel. This build need to function rather perfectly on all of them!
On the modulation side of points, it’s designed to be as analog-helpful as feasible. Relatively than just spitting out rough square waves, it modulates them into good clean sine waves with less harmonics. On the demodulation side, it’s got an LM393 comparator which can go through details on tape and spit out a cleanse square wave for quick decoding by electronic circuitry.
If you find your self striving to get better aged info off tapes, or producing to them for a retrocomputing task, this build could possibly be just what you need to have. [Anders] even goes as considerably as demonstrating its use with an old reel-to-reel deck in a beneficial YouTube video clip.
There genuinely were being some odd techniques of storing data way again when. Just request IBM. Movie just after the crack.