Slashdot Mirror
Yamaha CD-RW Drive Writes Images In Substrate
johnny5 writes: "Yamaha has recently demonstrated a new CD-RW drive that can write images into the unused space on a CD-R disc after the data track is written. The technology, called DiscT@2(TM), is due out in Japan in July. The images print on to the CD at approximately 250dpi, making graphics as well as text possible. More info can be found at Yamaha's CD-RW site (in English) as well as at Akiba PC Hotline (in Japanese, with better pictures. Babelfish for suitably akward translation). No word on a timeframe for U.S. availability"
So its
pronounced as Disctatoo trademark LLSHow do normal people know how to pronouce this or non-english speaking people like me. In German it would be "DiskTatzwei" trademark LLS. So Marketing only focuses on the english speaking clientel or what ?
... whenever a text is transmitted, variation occurs. This is because human beings are careless, fallible, and occasiona
Why ?? if you made the last (outer) track on your cd your image track, then you simply need to correctly encode the data in that track to produce an image. You would need to know the total amount of data in previous tracks and the data density to be able to calculate your starting radius. But as the first poster says from that point it's a matter of maths and a correctly formatted file to burn to disk
Assuming it is as you say it is not so easy. You need to insure that the writer will not barf. After all you feeding it with some data which according to the red book is garbage or pretty close to garbage. So the writer should allow turning off all error and sanity checks.
Alternatively it is very good software that merges an image on top of data that is acceptable to a normal CD writer.
In either case it is not just PI, elementary calculations and a bitmap.
Baker's Law: Misery no longer loves company. Nowadays it insists on it
http://www.sigsegv.cx/
Actually no. When real data is written to disk there are 3 layers (iirc) of error correcting/detecting that would disrupt the pattern. In fact if I understand the format correctly data is written in such a way that it can be recovered from multiple physical locations on the disc (to prevent a single scratch from ruining things). So writting long strings of 1's and 0's wouldn't quite do it. You need to be able to tell the laser when to turn on and off. This is something that normal drives don't allow. For the conspiracy theorists out there this is in compliance with the wishes of companies like Macrovision ;). Hmmm could this be used to create perfect 'backups' ;) of games?
Thoughts on tech, Software Engineering, and stuff
So it will only "draw" on unused parts of the disk, basically taking up space... crap.
0 622/image/nya2.html
Don't they mean literally the unused part -- the space in between the pits that the laser writes?
Look at this picture here:
http://www.watch.impress.co.jp/akiba/hotline/2002
"And like that
You can't do this on mass produced CDs for two reasons:
1) Mass produced CDs are pressed, not burned. So I don't even know if this process will work for a pressed CD which uses a different authoring process.
2) Even if this was possibile in that regard. Having a unique CD key pressed onto each CD would result in creating n templates (where n=number of cds pressed) which is too expensive to be useful. This is sorta the same reason as to why we see CD Keys on cd cases, but never printed onto the front label side of the cd.
I'm not convinced by this -- it looked to me like they ruined a whole CD to draw pictures all over it, and by "unused" they mean the part not written.
double sided cdr disk would have to be twice the thickness (and consequently twice the mass...) of a regular disk, because the data is actually recorded on the 'upper' side of the disk; the plastic actually helps focus the laser onto the grooves. This is why it's far easier to destroy a CD-R (and a regular cd too) by scratching the label side than scratching the 'data' side.
A double sided CDR would have to be exactly like two CD's stuck on top of each other, or they'd have to do some extremely fancy tricks to get the laser to focus properly through a data layer.
ìì!
"Customers can put graphics, such as signatures, logos, memorandums, and photo images onto CD-R's unused area after data writing."
Look closely: there is a very small data area (inner circle) on the picture, all other space is unused.
Cd drives have a very mild notion of their absolute position along the disk. I bet this drive has an extra sensor for angular position on the spindle.
This post was compiled with `% gec -O`. email me if you need the sources
Score:5, Insightful ???
he doesnt think a normal cd laser can make picture pixels that are hundreds of times bigger than the pits that are burned for data? think about it, the pixels in the pictures are visible to our eyes, try to imagine the size of the 0s and 1s. this is absolutely outrageous what he is saying and the fact he got modded as +5 is equally outrageous
I've had experience putting images on mastered CD's, so I'll give you some technical facts.
Firstly it is not easy to do through software, although it is technically possible (and has been done already). Basically different CDR's have different track pitch and pit length, which means you'd need some way of calibrating for the media. The pitch and length are the important parameters in determining where a bit in an image will end up on the CD. The further out on the CD the greater the number of bits per rotation, because CD was designed for CLV. So software has to be very precise and know these parameters EXACTLY.
Also, from a software standpoint, the most data you can send down per sector is 2448 bytes RAW. Note that RAW data is not all of what ends up getting written on the disk. There is still C1&C2 error correction that gets written physically on the disk that you cannot control (it is generated by the chipset). The stream also has scrambling applied, and the result is an image that is pretty much correct, but is fuzzy because of the C1&C2 that are out of the control of the software.
The good thing about the Yamaha is it writes in constant angular velocity. This makes it easy to write the image because one line of the bitmap can be applied per rotation. CAV is the way the images are written at mastering. Also, I'd assume that the Yamaha drive is in control of the full stream, so you'll be able to get perfect images because it won't be generating any error data.
One last fact is that images look a LOT better from the top of the CD. This is because the plastic part of the CD is underneath and distorts the reflection when viewed from below. So quite a few companies burn the images in reverse (so they are viewed correctly from above), and only print near the center of the disc. The question is will CDR manufacturers remove the label on top so you get the best effect.