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NEW Cassette Recorders!

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2 minutes ago, atrax27407 said:

Did you buy all the store had?

 

This one has six.  I’m keeping one, and two are spoken for, so I have three left for people that want to buy them.  $5.35 plus postage each.

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If anyone managed to miss these, and @acadiel has run out, I picked up the last two in town today.  Offering them at $5.40 each plus shipping.  I am fairly confident I can just slap a label on the box and get them out.

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Another bonus with these cassette recorders: they come with a microphone, a tape (looks to be a C-60,) and a 5V 1A power supply.  Unlike our standard Program Recorders, it does not have three power sources (AC-IN, DC-IN, or battery,) but rather just the DC-IN and battery.

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15 minutes ago, OLD CS1 said:

Another bonus with these cassette recorders: they come with a microphone, a tape (looks to be a C-60,) and a 5V 1A power supply.  Unlike our standard Program Recorders, it does not have three power sources (AC-IN, DC-IN, or battery,) but rather just the DC-IN and battery.

I had to go back and check the box. I would have missed the cassette hidden in the packing material. Thanks!

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Just be mindful about the "not so reliable" nature of those Onn cassettes.  Just a few rewinds, and I noticed audio distortion from stretching. For dictation, it probably would not be that much of a problem, but for data storage, it certainly is.

 

It's good enough to test the recorder, and to play around with it if you dont intend to use it for heavy use.  If you intend to use it regularly, get yourself a quality metallic tape from one of the hoarders we seem to have here. :P

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Durability of the media carrier aside, I would like to understand how you see a metal tape as superior for data recording.

 

From everything I have read over the past year or so since I started making my tapes, anything more than Type I for data recording appears to not only be a waste, but also in poor judgement for longevity.  The high-bias used for recording on metallic Type II and Type IV tapes is not present in standard, or Type I, decks, which results in a more muffled recording on the tape.  Previous experience recording music, both analog and "digital" sources has given similar results, which is why I purchased a recording deck with settings for CrO2 and Metal.

 

The cause of the muffled play-back sound is partly due to the missing bias in the recording process and the effects of coercivity similar to using an HD floppy disk in a DD floppy drive.  The frequency ranges used by computer data output require neither the dynamic range nor frequency resolution provided by high-bias tapes.

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Mostly, it's just that the tape medium itself is mechanically more durable, and less prone to distortion.

 

In Ye Olden Days, adjusting for the differences in recording media could be accomplished with a tone knob; A thing that is conspicuously missing from the walmart Onn deck.   I would be just fine with a type I cassette that was manufactured with a more resilient plastic. Whatever that iron oxide is embedded in, it clearly is not proper stretch resistant mylar.

 

Cassettes used for data get started, stopped, rewound, fast-forwarded, and held on pause far more often than cassettes intended for dictation or casual audio playback.  This means tugging forces in both linear directions on the tape are greatly magnified when used in a data storage role, and inferior tapestock quickly becomes unusable. (such as with those Onn cassettes, in my experience.)

 

The magnetic particles embedded in the type IV cassette make the plastic "stiffer", (which is partly what contributed to read-head wear, along with the Mos hardness of the particles themselves being higher than that of the polished metal pickup), which makes it less susceptible to stretching.

 

"squeaky", stretched tape that skips, jumps, and does not reliably take or playback a recording is a vastly bigger problem than muffling from the lack of strongly biased recording.  The latter can be somewhat addressed with an amp and a filter (we are after frequency pulse oscillation, not intelligible words).  Not so much the former (since it causes the frequencies to get distorted all over the place.)

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Durability aside, what would we do to account for long-term noise and degradation of signal caused by migrating domains when a normal-bias mechanism records to high-bias media?

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Posted (edited)

Redundant backups, and routine blanking and re-recording.

 

In the modern era- Retention of the audio sample in uncompressed PCM format on solid state media, to facilitate archival.

 

Edited by wierd_w

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So, in the modern era, tape recording media formulation or quality is irrelevant.

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Posted (edited)

Not for archival.

 

For use as a transfer medium, yes.  Just one kind of problem is worse than another.

 

Essentially, this is the argument:

 

Recording to tape (to load again quickly later, but not for long term archival) only to have it fail miserably because the tape has stretched, is more costly to the user than recording it to the tape and being able to play it back a few times before domain migration occurs. This is because you have to replace the tape in addition to re-recording the data to the tape. In the case of magnetic domain migration, you do not have to replace the tape, just bulk-erase it, then re-record it.  Assuming you have the equipment, bulk erasure takes just a few seconds of user time. In both circumstances, the user must re-record the data again. You do NOT get a pass on this, in either circumstance.  In one of those cases, you can re-use the cassette afterward. This makes this case preferential. Further adding to this, and depending on the quality of the cassette in general, El-Cheapo type I cassettes on the market today will fail mechanically much faster than old type IV cassettes will fail from magnetic domain migration, further increasing the preferentiality of this mode of failure over the other. (While it is sure to happen eventually, it will take much longer to happen, will happen less frequently, and will cost the end user significantly less in terms of time and financial expenses.)

 

The error you are having is in believing a cassette tape is viable long-term storage.  It is at best, an intermediate form of storage.

 

Edit--

 

On reflection, if this is the use case you have in mind:

 

User records once, does not rewind, does not pause, does not stop, does not run tape completely to end to where auto-stop happens, etc--- and thus avoids nearly all forms of stress on the tape--- then puts the tape away in a cool, dry place, and pretends this is archival.

 

then type I cassette is a better choice than type IV, because it is less likely to have the domains bitflip spontaneously, because the media has been written onto standard bias media, with a standard bias recorder.

 

 

That is not the typical use case I would envision for a daily driver cassette, however.

 

For a daily driver, which gets written to frequently, gets rewound frequently, gets paused and or stopped frequently. Gets both sides of the tape used frequently, etc--- the durability of the tape is more important than the risk of bit flip, and the costs of repeatedly replacing the tape with new media because it gets stretched quickly adds up.

 

 

Edited by wierd_w

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As I recall, most standard tape recorders have electric erase heads that can't completely erase a metal tape in a single pass. Overlooking this can be an issue!

 

Anyone have experience with implementing higher speed, higher bias, or AM recording???


A slight increase in motor speed, will improve high-end response, eliminating most tape errors and improving longevity.

 

The original dope formulations had very low energies compared to today's formulations. This resulted in a wide variance in audio levels between different types of tape. I believe it was mainly because of this, that FM recording was chosen. FM recording provided more uniform characteristics, particularly with regard to volume and high-frequency equalization. They knew tape formulations would improve, and outgrow the CC standard otherwise. However, the FM standards applied then, seriously limit both bandwidth and volumetrics available with today's formulations. Today's formulations can handle higher biasing and amplitude range. From a fidelity based viewpoint, I feel FM recording may have been a very bad idea, particularly for magnetic tape, as it appears to be the basis of the incredibly high S/N ratio(white noise).

 

These opinions are based mainly on some experiments I conducted around 2001, in which I used an older model VCR that had a DC tape drive motor. I first connected the speaker output from a low-power amplifier(from a small tape recorder), directly to the VCR's tracking head(no bias). Only with the amp at full volume, could I get any audio reproduction(badly clipped). Next, I tried putting an old, used, "AAA" carbon battery, removed from a remote control(high internal resistance), in parallel with the tape head. I started recording... as I was distracted, it took me more than 10 seconds(after the leader had passed) to begin speaking. When I tried playback, with the addition of biasing, I expected to hear white noise when the leader ran out(this thought is what had distracted me)! I had the volume turned up to about 75%. There was NO white noise! I became impatient, thinking this test was going to fail, and I almost hit stop in the last few seconds of the test. When my voice played back ...in perfect clarity, I was truly astonished(and startled)! I had not, to then, and have never since, experienced, recording/playback of audio with this LOW of a S/N ratio! Digital 96k and up is pretty nice, but still ...some(barely detectable) noise. As for amplitude range ... you could probably set levels so as to hear the sound of a pin drop right next to a loud explosion, w/o distortion. I have to wonder what the clipping voltage is for metal tape! Unfortunately, I was moving, and in the process of tearing everything down, so never got the chance to try with music! Oddly, I decided to leave this apparatus behind.:twisted:

 

This experiment reminded me both, of ...Bell's acid spill, and of Sprint's "Pin drop" long distance campaign. Wow, before they split the bandwidth up(1985/'86), long distance calls from NY to LA, sounded clearer than LOCAL!:-o

 

I have found myself revisiting the memory of this experiment somewhat... during the last week...

My current intrigue with IR Remote control signaling, got me to thinking... I'm just a few lines of code, and a few cables, away from being able to attempt... the usage of this protocol, for magnetic tape data storage. If I can successfully use AM, I should be able to interface a CRU port directly to the tape head, perhaps eliminating the need for FSK or the like. I'm dreaming that... I might reach the maximum speed I can stream data through the CRU. Don't know what that would be exactly, but I'm guessing that by reducing the pulse widths slightly, I might get around 5k per second. That sounds like less than 10 seconds to save 32k. This would seem cool(if not useful), just because.:-D

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Quick note on the Onn cassette deck.  While it does work, I found that on mine the motor runs slower when connected to the remote plug.  Fortunately the TI adjusts timing during the read operation, and the speed difference does not appear to be enough to put the play-back of tapes recorded on other devices out-of-spec.  The difference is perceptible to the human ear.

 

I have not tried to see what happens when taking a tape recorded on this deck to another.  I expect that if the slower play-back speed does not effect reading, that the higher play-back speed should equally be within range.

 

I loaded Simon's Saucer with it from original tape and, even with the slow speed and several drop-outs, it loaded just fine.  A neat little game, too, with some interesting programming strategies.

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If anyone managed to miss these, and [mention=22866]acadiel[/mention] has run out, I picked up the last two in town today.  Offering them at $5.40 each plus shipping.  I am fairly confident I can just slap a label on the box and get them out.

Yep, I still have several left.

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And if you do not open it carefully, the bar holding the keys in place will dislodge :)  I noticed, too, the record head is passive (magnetic, rather than powered.)  Everything is connected to the mainboard with disconnects, which is nice.  I opened mine to see if there was an AC power circuit as the port was covered.  Obviously not.

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10 minutes ago, OLD CS1 said:

And if you do not open it carefully, the bar holding the keys in place will dislodge :)  I noticed, too, the record head is passive (magnetic, rather than powered.)  Everything is connected to the mainboard with disconnects, which is nice.  I opened mine to see if there was an AC power circuit as the port was covered.  Obviously not.

Yeah, apparently it was a mold used for other cassette players back in the day.  
 

 

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On 6/27/2020 at 9:35 AM, acadiel said:

Yeah, apparently it was a mold used for other cassette players back in the day. 

I bet it would not be difficult to build an AC power circuit based on a simple capacitor dropper, bridge rectifier, and a voltage regulator.

 

When I get a second or two, I want to work up a schematic and figure out why the motor speed drops when used with the remote.  Do you have that problem?

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Rather than AC input, I would rather use the knock out (and spacious realestate inside) to give a data connector, and a more advanced tape controller.

 

But meh. :)

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10 hours ago, wierd_w said:

Rather than AC input, I would rather use the knock out (and spacious realestate inside) to give a data connector, and a more advanced tape controller.

 

But meh. :)

To interface into what?  Sounds like a much bigger project.

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