Encoding Data for Audio Tape?
Kris_J asks: "I've recently purchased and installed an audio cassette deck for my PC. It makes recording to and from tape particularly painless, but I'm looking for some funky other stuff to try. Along the lines of my new old SuperDisk FD32MB that can store 32MB on a normal 1.44MB floppy, and my Cuttle Cart that can load Atari 2600 games from encoded audio I'm wondering if there's any program that can encode a file as audio that can survive being recorded to audio tape or compressed as an MP3. I'll worry about 'why' later."
MP3 is a lossy compression. If lossy recovery is OK with you, fine. For storage to tape - maybe cwpcm the file after uuencoding it. I can't remember if there's a morse code character for each character used by uuencode.
on a more practical line - send it as straight ascii, using the ham radio interfaces in Linux, through the sound card. decode that with the same interfaces and you're done. Those tools are used to loss, but I'd expect 100% copy on and off tape.
The device itself is quite simple. It's a 5.25" device with a standard power connection. It also has a ribbon cable that runs to a simple adapter that fits in a slot in the case (thought it doesn't plug in like a card) -- from there you connect it to audio in/out and a serial port. Software is seriously basic and I think Windows only, but you can just set a few settings and press a button to have it convert an entire tape, both sides, to an MP3 file. I then cut it up using MP3DirectCut. Just converted an old Vangelis tape yesterday.
So, yeah, it's basically a tape drive with Line In / Line Out and a serial port. However, I'm barely a programmer, just a bit of PHP and SQL, no C, no drivers, no comms, so I'm not up to the task of writing anything myself.
A more useful cassette tape oriented question that I have been thinking about is: Has anybody come up with a software package to emulate an audio cassette deck using a PC with a sound card? It seems like it would be a trivial task and it'd be cool for people with 'classic' hardware. The old TRS-80 or Sinclair 1000 would be more useful with a 100% reliable storage system like an old Pentium Machine that mimics a cassette. It would need audio in/out and possibly a digital input for 'motor control' that many old computers used.
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- for both the tape and the recording heads:
- Baseline noise level
- Effective response time
In other words, the quietest reliable volume and the shortest wavelength possible. You'll likely want to find or write an app that encodes ASCII data as 16-bit audio, choosing a high- and low-volume to record binary onto an analog medium. To counter your effective response, simply choose a good per-bit duration -- like cheap error correction. There are many, many ways to get this encoded, but your problem will be the low playback quality of the tapes. Another, more involved, solution would be to assign a specific frequency to each binary place-position, so you can assemble the completed byte-sound, record to tape, and disassemble into the component frequencies. This method will yield a higher density, but I'm afraid you'll probably encounter those quality issues I mentioned before... I'd say it's time to hit the google! Good Luck!Dear Slashdot: I'm looking for a way to store data so that the probability of recovering it is extremely low. I can't just delete the files since my company has a legal obligation to store them, so /dev/null is out of the question. Ideally I'd like some sort of crappy, hacked solution using media which is totally inappropriate and unreliable. I've already tried writing 32MB to 1.44MB floppy disks but that just wasn't bad enough. In your opinion, what is the shittiest data storage technology available ?
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