flat assembler
Message board for the users of flat assembler.

Index > Main > save CD/DVD data info file

Author
Thread Post new topic Reply to topic
b1528932



Joined: 21 May 2010
Posts: 287
b1528932
Recently i was playing with some iso files, and i was thinking - is it possible to copy a CD or DVD exactly bit by bit and save this in a file?

- Can i read everything from CD/DVD? When i read sectors from HD, i cant read anything but sectors themselves - its controlled by hardware and there is no sense in changing it.
- Since CD/DVD has no sectors but rather a spiral track, how do i even access particular data piece?
Post 15 Jan 2011, 19:40
View user's profile Send private message Reply with quote
ManOfSteel



Joined: 02 Feb 2005
Posts: 1154
ManOfSteel
b1528932 wrote:
Recently i was playing with some iso files, and i was thinking - is it possible to copy a CD or DVD exactly bit by bit and save this in a file?

Sure: dd if=/dev/<some device> of=test.iso bs=2048. Or if you're on Windows you can make an image using some expensive software like Nero :p Just kidding, dd is now available for Windows, or so I heard.

b1528932 wrote:
- Can i read everything from CD/DVD? When i read sectors from HD, i cant read anything but sectors themselves - its controlled by hardware and there is no sense in changing it.

Why, you also want to read the drive's firmware? Smile
And "no sense in changing" what?

b1528932 wrote:
- Since CD/DVD has no sectors but rather a spiral track, how do i even access particular data piece?

They do have sectors/blocks. And you can read them just like you read any other media: using your system's API or by making your own drivers.
Post 15 Jan 2011, 22:34
View user's profile Send private message Reply with quote
b1528932



Joined: 21 May 2010
Posts: 287
b1528932
ok, but sectors on CD/DVD are diffrent than on hdd. I cant just position head over a cylinder, and issue a read of sector.

I guess i will have to loop through every single one sector untill head is over one i want to read. Cdrom will know it because it will count passed ectors, effectivly reading all of them. Is that right?

This question might be stupid, but how do i know the sector size?
Not only on cd, hdd also? There is no mandatory 512 bytes (or 2048 bytes in dvd/cd), it can be any arbitrary value. How do i determine sector size on hdd, and how on cd? Does cd has this information in TOC?


Why lead-out is needed, especially that big? why first leadout must be larger than following?
Post 16 Jan 2011, 07:29
View user's profile Send private message Reply with quote
Display posts from previous:
Post new topic Reply to topic

Jump to:  


< Last Thread | Next Thread >
Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Copyright © 1999-2020, Tomasz Grysztar. Also on GitHub, YouTube, Twitter.

Website powered by rwasa.