Back in the early days of the residence personal computer revolution, info was generally saved on tape. Even much better, those people tapes would make an almighty racket if you played them on a stereo, simply because the details was saved in an audio format. The Easy Common Modem from [Anders Nielsen] is crafted to do the job in a identical way, turning data into audio and vice versa.
The job consists of a circuit for modulating information into audio, and demodulating audio back again into facts. It is “universal” simply because [Anders] has made it to be as format-agnostic as possible. It does not subject no matter if you want to retailer details on a electronic voice recorder, a cassette deck, or an aged reel-to-reel. This develop really should get the job done reasonably effectively on all of them!
On the modulation aspect of items, it’s designed to be as analog-friendly as probable. Somewhat than just spitting out tough sq. waves, it modulates them into awesome clean sine waves with fewer harmonics. On the demodulation aspect, it’s acquired an LM393 comparator which can read information on tape and spit out a cleanse sq. wave for quick decoding by electronic circuitry.
If you come across by yourself trying to get better outdated information off tapes, or crafting to them for a retrocomputing project, this create may possibly be just what you need. [Anders] even goes as much as demonstrating its use with an previous reel-to-reel deck in a practical YouTube online video.
There seriously have been some unusual means of storing details way back again when. Just question IBM. Movie right after the break.
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