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."

Comments

tape yes, mp3 no

[n9hmg]

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.

From the linked thread

[NanoGator]

On the "Fit 32 megs on a floppy" link to an old Slashdot story, I ran across this 'first post' comment:

"The next version of Windows should fit on 5000 of these..."

Just thought it was amusing that Windows XP is distributed on one CD, RedHat is distributed with 5.

(Sorry, NFI how to answer this guy's question...)

Brings back memories

[Rxke]

of how i used to curse, as a kid, on my crappy cassettedeck not wanting to load my programs... Diskdrives too expensive, not to mention harddisks... And you want to do that VOLUNTARILY? Geez...

This looks like a pretty cool product.

[mellon]

Where did you get it? It looks like it's actually controlled over a serial port - is that right? Seems like it would be pretty easy, if that's true, to come up with a driver for it - you wouldn't even need a device driver, but just a control library that knows how to talk to the serial port. Are you using it from Windows or from Linux? If Windows, wouldn't getting it running on Linux be a fun hack job? :')

This would be handy for me because it'd provide a way to master tapes for duplication without requiring me to put my hands on the machine all the time to cue up master tapes.

Anyway, stop fooling with your silly tape writing project and get going on telling us how this thing works! You can always write the tape using by running a Z80 emulator and running Tarbell BASIC on it, can't you?

Re:This looks like a pretty cool product.

[Kris_J]

Okay, long story. It appeared on one of the Gadget blogs I frequent and I tried to get it directly and failed. However, my credit card's loyalty scheme includes something about "Rewards as broad as your imagination" where you can tell them what you want and they'll get it for you. After a month or so Citibank were able to get in contact and have the product shipped to me.

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.

Geez

[Otter]

I got to "I've recently purchased and installed an audio cassette deck for my PC." and was thinking of a stupid comment to make about how he could save his 10 PRINT "I RULE!, 20 GOTO 10 program on it.

And then it turns out that's actually what he wants to do!

Suggestion -- here's your opportunity to learn a bit about file I/O. You know how to write to and read from the device? Hack at it a bit and write your own toy utility. That'll benefit you far more than finding something on Sourceforge and playing with it for 5 minutes.

Not a useful comparison

[V. Mole]

That's because the Windows XP CD doesn't include Office, or Exchange, or SQL Server, or Photoshop, or ... I think you know where I'm going with this. Still not a completely accurate comparison, but a lot closer.

Not to mention the sourcecode.

Re:Not a useful comparison

[NanoGator]

Yep, you're right. However, spanning that many CDs is dangerous. I tried to install Redhat 7 or 8 (I forget which, but I can tell you it was only 3 CDs, not 5.) and on the third disc, I discovered the media was bad. Redhat's installer wasn't smart enough to deal with an error like that, and never gave me the opportunity to 'retry'. Instead it just stopped. So I had a partly installed Linux that'd only work in CLI mode, and root had a blank password. Heh. I had to start the entire install over with a fresh set of discs. (Fortunately, this problem, if not solved already, is fairly easy to fix.)

In any event, I wasn't faulting RedHat for it in my original comment. I'm not mad at Redhat for that other than with the problem mentioned above, thought it was nice to not have to go download a bunch of stuff. What makes it interesting, though, is there are people out there who try to measure 'bloat' by how much space the install of an app takes up, and sometimes times change and work against you, as with the case of that poor AC.

Re:Not a useful comparison

[cowbutt]

I've had a bad file during a RH install. I noticed that Anaconda was retrying the rpm over and over, so I switched to the shell console, unmounted the CD, ejected it and replaced it with a good CD and remounted. The install continued as normal and I was left with a clean install. I'm not sure this will work every time and it's certainly not documented or supported, but it worked for me.

--

Why not?

[fm6]

I'll worry about 'why' later.

Spoken like a true hacker!

Not

[fm6]

You lose some information when encoding to MP3, but that information you lose may not be important.

But how do you know whether important information has been lost? You'd need a pretty thorough understanding of the theory behind the MP3 algorithm to know that. Which might well lead to a variation that can safely compress a data stream -- but that's an exercise in advanced computer science, not casual hardware hacking.

A more useful 'Ask Slashdot' question.

[IM6100]

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.

Can you tell I've done something similar before?

[hattmoward]

You'll probably want to grap the tech specs for that deck... I don't know what sort of interface this provides you, but if it's just an analog tape recorder with audio in/out connections, there are a few things you'll need to consider:

• 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!

my question

[Zork the Almighty]

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 ?

i hope i hope i hope

[Drunken_Jackass]

Geeze, i hope someone comes up with a solution to this dilemna. You see, i don't want to buy an iPod, because that would be too easy. Instead, i just bought a "Walkman" - it's this cool retro hardware that can play audio tapes while you walk...or sit, or stand even! So i need to find a way to convert my .mp3 collection to .wav files that i can then transfer to audio cassettes (or "tapes") so i can pop one of them into my Walkman and listen with reckless abandon while i park cars (i'm a valet).

I hope this is possible. I want to see if i can induce some sort of ass-backwards, retro-technical vortex that will suck cars from one location to another.