What keeps people from creating optical tape?

[FishTankX]

What would happen if you cut an optical medium (Like CD-R or just pressed) and rolled it up into a tape sorta thing? Wouldn't that have much more surface area?

What would be the difficulties with implmenting it?

 

[RossGr]

I guess you aren't old enough to recall the hassels of a cassette tape. With a tape you do not have quick easy acess to all tracks, also the tape itself is a fexiable media. That means it streachs, this inconsistancy in the meadia makes high fidelity very difficult. The question is not how but why?

 

[AndyHui]

What a pain. What if I am at the beginning of the tape and want to jump to a chapter in the middle or the end? How long do I have to wait for the tape to scroll and search?

 

[KenGr]

I think there are two issues here. One is the random access issue already mentioned which is a weakness of tape formats in general. However, I believe all optical media are rigid. Tape (or "floppy" disks) will have a problem maintaining the close geometry required for a optical or focusing system.

 

[thraxes]

German scientists have managed to use a roll of office tape to store information without unwinding it... in a nutshell: just simply turn the roll and focus the laser to the appropriate layer.

Was only able to find german pages on the subject though:

http://rhein-zeitung.de/on/01/11/12/internet/news1.html?a

Edit: Capacity of a 40cent roll of tape is 10 GB

 

[RossGr]

So rather then storing the information on the surface of disk, they are looking through the edge of a disk at varing depths to read the data present. Record it on a tape, wind it up once, then read by spinning the disk of material while looking through the edge.

Humm.... Interesting.

 

[FishTankX]

Now, with all of you ragging on tapes for the random access issue, i'm talking about in a data archiving and computer storage scenario.

Couldn't a relativley small tape roll (Maybe the size of those computer backup tapes, like DS-3) hold terrabytes if done in an optical fashion?

Oh, and I think if you used flexible plastic for the substrate you'd solve the rigid issue. wouldn't it be possible to just coat the surface of your normal run of the mil office tape type stuff with optical medium?

 

[Shalmanese]

Wouldnt the density of the tape be roughly the same as just a simple platter of CD's? Probably less since it would be hard to find optical tape that could handle to stress of being wound so tight.

 

[CTho9305]

Originally posted by: Shalmanese
Wouldnt the density of the tape be roughly the same as just a simple platter of CD's? Probably less since it would be hard to find optical tape that could handle to stress of being wound so tight.

you wouldn't have to wind tighter than scotch tape - consider the surface area of one roll of tape vs. the surface area of a CD... or am I misinmterpreting something?

edit: also, a roll of scotch tape has a smaller radius than a CD, so it might be possible to spin it faster

 

[FishTankX]

The question is this. How does the thickness of tape compare with the thickness of CD's? No contest. Tape wins.

That being said, you will have a higher density on tape than you will have on optical disc.

But have you looked at the surface area measurements for some of these tapes? It's astronomical!

 

[Shalmanese]

Well, I assumed the tape would be the same thickness as a CD otherwise, why not just use thinner CD's for archival purposes? If the tape is the same thickness, I dont see how you would gain a significan amount of data density. In addition, I dont know how flexible you can make optical storage mediums but I dont think you could make it anywhere as thin as scotch tape.

Plus, you are also missing the biggest concern about archival equipment: readers. If we invent some wierd and arcane dedicated tape readers, it is quite likely that in 10 yrs time, only 3 will exist in the world owned by millionaires in their personal museams. CD drives have been around long enough that there is still a reasonable chance that somebody can find an old one and transfer their material onto more permanant media when they realise its actually valuable. There are enough C64 nuts out there today to prove that any popular technology will still have remenants many years after it becomes useless.

 

[CTho9305]

Originally posted by: Shalmanese
Well, I assumed the tape would be the same thickness as a CD otherwise, why not just use thinner CD's for archival purposes? If the tape is the same thickness, I dont see how you would gain a significan amount of data density. In addition, I dont know how flexible you can make optical storage mediums but I dont think you could make it anywhere as thin as scotch tape.

Plus, you are also missing the biggest concern about archival equipment: readers. If we invent some wierd and arcane dedicated tape readers, it is quite likely that in 10 yrs time, only 3 will exist in the world owned by millionaires in their personal museams. CD drives have been around long enough that there is still a reasonable chance that somebody can find an old one and transfer their material onto more permanant media when they realise its actually valuable. There are enough C64 nuts out there today to prove that any popular technology will still have remenants many years after it becomes useless.

A CD needs to be thick enough to be rigid, and thick enough to protect the data (I think fancy CDs have another layer of plastic on top of the foil to protect it from both sides). With a roll of tape, it would basically be a cylinder that could be as tall as you want (limited only by the ability to seek across the width fast enough and it could be as many layers thick you can focus through

 

[YNos]

Originally posted by: Shalmanese
Well, I assumed the tape would be the same thickness as a CD otherwise, why not just use thinner CD's for archival purposes? If the tape is the same thickness, I dont see how you would gain a significan amount of data density. In addition, I dont know how flexible you can make optical storage mediums but I dont think you could make it anywhere as thin as scotch tape.

Plus, you are also missing the biggest concern about archival equipment: readers. If we invent some wierd and arcane dedicated tape readers, it is quite likely that in 10 yrs time, only 3 will exist in the world owned by millionaires in their personal museams. CD drives have been around long enough that there is still a reasonable chance that somebody can find an old one and transfer their material onto more permanant media when they realise its actually valuable. There are enough C64 nuts out there today to prove that any popular technology will still have remenants many years after it becomes useless.

a cd has to be a certain thickness or you will have a bit of fragmentation<not cool>...cant remember how thick they have to be right off hand, but i have saw what happens when one frags.....REALLY makes a mess of the inside of the drive.

 

[Jeff7]

Originally posted by: RossGr
So rather then storing the information on the surface of disk, they are looking through the edge of a disk at varing depths to read the data present. Record it on a tape, wind it up once, then read by spinning the disk of material while looking through the edge.

Humm.... Interesting.

This sounds like holographic storage. Might as well just go with that then.

 

[FishTankX]

Well, that wasn't my original idea. I was thinking of rolling a tape by a patch of lasers that would burn data small tracks at a time. You know, burn a track from the begining of the tape to the end, then reverse direction and burn the next track, etc.. until the tape was full.

But I know that while this seems like a hair brained idea, combined with CD-RW abilities and packet writing it could be like a truly massive floppy. While random access would be slow, it'd be good enough for archiving movies. See my tape drive thread in GH.

Besides all of that, the main point would be that you could hold 100s of GB on a single tape, versus having to run around looking for a specific CD. I've hated the CD hunt ever since the birth of the medium. It'd be so much simpler to be able to have everything on one scratch resistant media.

Also, due to the nature of optical tapes, you wouldn't have head wear either.

It'd also be ideal for audio.

 

[wviperw]

Yes, the tape idea could hold a ton of data and be good for backup. In fact, they already do that for large backup (use magnetic tape atleast). But as you stated, its got the huge disadvantage of not being random access. With new storage technologies on the rise (i.e. - 3 dimensional holographic storage), why settle for something less in the form of non-random access media when you can develop something better?

 

[Jeff7]

Ok, I see - a greatly improved tape drive basically. But wviperw makes a good point about access times; they are REALLY lagging behind in the mass storage arena. There we talk about access time in thousandths of a second, whereas the rest of the computer finds things in billionths of a second. More storage is also nice, but it's also good to be able to access any of the data quickly, even in backup devices.

 

[Howard]

How do you propose to make the lens skip across the width of the tape? Contemporary CD-ROM drives follow a single "line" until the end of the CD.

 

[NogginBoink]

In essence, what you're talking about is movie film being used as a storage medium, right?

In fact, Sony's SDDS sound system in movie theaters does this. They use an optical "barcode" between the sprocket holes to record the digital soundstream. It's picked up by an optical reader and converted to howevermany channels of sound. So the basic premise has already been implemented in a practical and industry-proven implementation.

The problem I see with this is that it'd be write-once technology. And perhaps that the data density wouldn't be as high as magnetic media.

But I'm sure that those problems could be overcome with r&d. All in all, I don't see anything about your proposal that is impossible or unfeasible. Magnetic tape has probably hit the point where it's just economically worthwhile to pursue.

 

[zephyrprime]

I remember reading about some researchers that were studying an optical tape drive that uses the same storage medium as CDRW's. Seems like a pretty good idea to me that would be pretty easy to implement. Such a drive would have horrible access times since it was a tape drive but I don't think that's a real problem because the real market for such a thing would be the backup market. Magnetic tape drive capacities have been really lagging hard drive capacities so some sort of technological improvement like optical tape would be great.

According to my calculations, my old extra large travan tape cartridge has 169 times the surface area of a cd. So if an optical drive had the same data density as a DVD+/-RW, that would mean a optical tape cartridge could have ~800GB of storage! Whooo hooo!

 

[dzt]

current tapes are fragile media, but new sinthetic materials can resolve it. accessing speed is the issue, so it can't be used for random access, only read and write in one directional - > for data backups.
and if a DVD's small surface contains some gig's, a cassette sized tape with the same idea will provide ton's of bytes.

anyone have technical datas ?