I am trying to burn a pattern of dark rings on a DVD. The idea is to bypass all the checksums and bit leveling usually done when burning a data DVD.I want to make a pattern of 95 dark rings per millimeter across the whole 33 milimeter wide data area of the DVD.

I have made a 4 Gig text file with 3135 long strings of NUL and } characters. If I can burn this file to the DVD I should see rings. Instead of rings, I see a gray pattern that I think is caused by the DVD writer adding checksums and using data writing rules that equalize the pits and blanks.

What I am wishing for is, how could I use the dd command to blast the data onto the DVD without the writer doing all the bit twiddling that neutralizes my hoped for pattern? I can't figure out an outfile name that gets the data all the way out to the hardware.

The physics project is I am trying to make a 95 lines per millimeter diffraction grating. I am trying to look at the absorption of very long wave infrared light by carbon dioxide. CO2 has big absorption bands at 14500 nm, 4270 nm, 2710 nm which are way longer waves than red laser light at 635 nm. The grating has to be a mirror which I hope to make by peeling the plastic coating off of the DVD.

For making my 4 Gb text file, I used the following command to make lines, then concatenate files with the doublecaret>>
yes "__________" | head -12800 > filename # Work out string length etc. with pocket calculator

My website: http://www.lowco2america.com/2017/12...n-us-time.html

Writing to cd/dvd is more complicated than dd will allow. You won't succeed with dd.

There's a lot of questions asked and answered about media, formats, speed,and disk types (dvd-r or dvd+r). I would suggest that you try with cdrecord. You can write an email to that guy if you don't succeed. He is an oddball, but knows the area well.

I would start with mkisofs, which is as near to cd as you will get. That creates an ISO of your text file, and the file system which counts as distortion. It may be good enough. Otherwise investigate Lightscribe. That writes a cd label on the front of a cd which can be a picture format. I used print the same thing twice for added saturation. You may be able to use that. It checks for the front of the cd and you would have to change the code to get it on the back.