Question about how CD-writers work

i can tell you how a CD is made, but the idea of the 1 and 0 is not possible. well, maybe it IS, but i dont think you have the millions of money to develop the CD used, and buy the materials you need for it. At least it cant be done with a normal cd or CD drive.

a CD is a disk. it has a layer on it that can be burned with a laser. If you make a hole (its microscopic) that would be read as a 1, and the empty(unburned space) space would be read as a 0. Now you would say: If i burn these holes in a patters, it should be seen. This is only half true. the Holes and not deep. in fast, a human hair is WAY thivker, then those holes are deep. the patern would be VERY hard to see, and for sure it could be seen with the bare human eye.

The second catch is that there has to be some data on the file, if you want to have a readable CD. the CD must at LEAST contain the file structure, what file system is used exetra. that space cannot be used for the image. If you use it, the CD will be unreadable. No prob, since burning the image would make it unreadable at all, since the CD has some 1 and 0 on it. those 1 and 0 from the image will be read as if it was normal computer data. but it isnt, and the computer doesnt get a thing of what is standing there in programm language, simply because it doesnt mean a thing.

The various manufactures dont have exactly the same kind of CD, but the concept is so closely related, it doesnt matter with manufacturer made it.

If you really want a graphic, there is CD designer software, that work with foil, that contains the image. the image is never on the data side however.

Sorry to help you out of your dream, but with a standart CD-R its impossible to make such a CD. it just cant be seen, since the holes are just a few nanometers deep, and the difference between a hole and no hole is not seen by the human eye

But i must say, it was a very fun question to answer :D. it REALLY made me use my brain on cd burning concepts. it would be a nice idea if it could. 2 bad it cant work :( i would have like such a cd ;) (sorry if the answer is a bit messy)

also check this article out from top to bottom, except the price list.

http://www.pantherproducts.co.uk/Articles/Storage/cdburner.shtml

hmmm thats something that i didnt really expect.... the best i expected was an (almost invisable)image if you held it into the sunlight.

well, i dont think it will get more then faint, but since i was pessimistic about the image in the first place, dont take this to serious.

i however think that making an actual image, will be a REAL tough job. ever seen those ANSII arts some sites use? they are a LOT of work to make, and thats just 1 A4 page with text takes several days, depending on someones skill. the disc itsselve is also round, so an image thats made on a flat surface, will be screwed on a round disc, because its written om something thats round and rotating. to be honest, i would rather paint the golden gate bridge then figuring all out :) 600 mb is still 600000 kb ( no i round the things, dont feel like calculating exactly), wich is more then a million of bits, that are used for the 1 and 0. of course such small things you never need cause they cant be seen, it will still be real tough to pull of.

What you need to know is the rotation, the bits per turn (and the turns get bigger, wich means other circles). i doubt if this can be really pulled of (correct that, if its worth the time). but if it CAN be pulled of, it would be real cool :)

I suggest that you make another laser driver, wich makes the burning not circulair, but liniair. thats also hard, but at least the images are way more easy to make. still itl be a REAL tough job.

I'll let you know any more findings.  What you've said already deservs lots of points but I'll leave the question open in the hope of finding other people to contribute.

thanks :) keep this topic up to date with findings. i really like the idea (im sceptic, but if noone tried, we would never have invented anything ;) )

oh, and i found this:
http://www.howstuffworks.com/cd-burner.htm

it may seem a little symplistic at first, but it contains the data you need (cds burn inward out, thats vital if you wanna burn an image, and it says a cd has 5 km of trach lenght on it)

It sounds like you want to do something that already exists, check out Yamaha's DiskT@2 technology:

http://www.yamahamultimedia.com/yec/tech/discta2_01.asp

Also there's a pretty good article on the process at CD Freaks (as part of their review of Yamaha's burner)
http://www.cdfreaks.com/article/88/4

hmmm so data is written like this:
 set1(part1) set2(part1) set3(part1) set1(part2) set2(part2) set3(part3)

so then the data will be much harder to damage. now only: the image will be WAY harder to write.
Maybe you should make a file and write a line of 00000000000000000 and a line of 1111111111 on it, and burn it on a disk. then you can see how it is distributed. i guess there is a certain patron in it. i dont know if there is any software that shows how the data is burned (something that scans and displays the bit order (like 0010011100101))

i dont know if every CD burns in the same patron, since it are other manufacturers. but with some luck, the CD burning software chooses that.....

Well, as I understand it, the issue is not really getting the burns onto the CD - with the right level of mapping and control, you can burn where-ever you want, which is what the DISKt@2 processs does. The problem is that the burns aren't readable as data, because you deviated from the EFM patterns. So to achieve your goal, you'd have to come up with a new data writing and retrieval algorithm.

Try reviewing the following:

http://www.laesieworks.com/digicom/Storage_CD.html

http://www.disctronics.co.uk/technology/cdbasics/cd_frames.htm

OK, I see what you are saying. I was thinking you still wanted to preserve _useful_ data, but that's not necessary, only that you can use correctly formatted data to produce the effect.

As an interesting aside, have you looked at the CDRdao driver? Seems like it might offer a bit of the extra control you need for what you are trying to do.

http://cdrdao.sourceforge.net/index.html

And this isn't what you asked for, but it's an interesting idea as well...

Finally, there is a ton of interesting information in the CD FAQ from comp.publish.cdrom,
http://www.faqs.org/faqs/cdrom/cd-recordable/part1/

Oops, left out the interesting idea:

http://www.lightscribe.com/