I was writing some assembly BIOS code and in general we use interrupt to access disk functionality. We give commands like seek to this sector read bytes etc etc. but how does disk knows whether it is first sector and similarly how does cd/dvd identify sectors as cd/dvd are inserted in cd drive from random position. Is there any kind of identification number associated with sectors in those hardwares?
How does sectors, track are identified on disk and CD/DVD?
790 views Asked by Rahul At
1
There are 1 answers
Related Questions in ASSEMBLY
- Volatile properties in Kotlin?
- Using multiple JVM languages in the same project
- Kotlin - IntelliJ Project Setup
- Kotlin let analogue which returns the receiver
- Kotlin 'when' statement vs Java 'switch'
- Use Kotlin extension in android java class
- Kotlin stub/placeholder function for unimplemented code
- Partial class delegation in Kotlin
- SugarORM + Kotlin: Unresovled reference "listAll"
- Kotlin JS - string to number conversion?
Related Questions in X86
- Volatile properties in Kotlin?
- Using multiple JVM languages in the same project
- Kotlin - IntelliJ Project Setup
- Kotlin let analogue which returns the receiver
- Kotlin 'when' statement vs Java 'switch'
- Use Kotlin extension in android java class
- Kotlin stub/placeholder function for unimplemented code
- Partial class delegation in Kotlin
- SugarORM + Kotlin: Unresovled reference "listAll"
- Kotlin JS - string to number conversion?
Related Questions in HARDWARE
- Volatile properties in Kotlin?
- Using multiple JVM languages in the same project
- Kotlin - IntelliJ Project Setup
- Kotlin let analogue which returns the receiver
- Kotlin 'when' statement vs Java 'switch'
- Use Kotlin extension in android java class
- Kotlin stub/placeholder function for unimplemented code
- Partial class delegation in Kotlin
- SugarORM + Kotlin: Unresovled reference "listAll"
- Kotlin JS - string to number conversion?
Related Questions in X86-16
- Volatile properties in Kotlin?
- Using multiple JVM languages in the same project
- Kotlin - IntelliJ Project Setup
- Kotlin let analogue which returns the receiver
- Kotlin 'when' statement vs Java 'switch'
- Use Kotlin extension in android java class
- Kotlin stub/placeholder function for unimplemented code
- Partial class delegation in Kotlin
- SugarORM + Kotlin: Unresovled reference "listAll"
- Kotlin JS - string to number conversion?
Related Questions in OPTICAL-DRIVE
- Volatile properties in Kotlin?
- Using multiple JVM languages in the same project
- Kotlin - IntelliJ Project Setup
- Kotlin let analogue which returns the receiver
- Kotlin 'when' statement vs Java 'switch'
- Use Kotlin extension in android java class
- Kotlin stub/placeholder function for unimplemented code
- Partial class delegation in Kotlin
- SugarORM + Kotlin: Unresovled reference "listAll"
- Kotlin JS - string to number conversion?
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
Popular Tags
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
Optical discs have one continuous spiral outward, and yes there's some intro area for the drive to find out the disc angle for the start of the first sector. A quick google didn't find specific details on how exactly it does this, but presumably some formatting / metadata outside the usable / user data.
Boundaries between sectors are marked by a synchronization code that's not used anywhere else (https://en.wikipedia.org/wiki/Track_(optical_disc)#Sector_structure). That description of Red Book audio sectors also applies to data CDs: a CD-ROM uses the same underlying framing as Red Book audio CDs, but with data inside that. (And another layer of error correction, giving 2048 error-corrected bytes of data per sector of 2352 bytes of first-level-error-corrected sector data.)
Tracks in an optical-disc sense are totally different from hard-drive / floppy "tracks". (Because there's only one spiral, not multiple rings of data). CD tracks are an arbitrary number of sectors, and track boundaries on audio CDs are normally placed at song boundaries.
Note that Cylinders / Heads aren't meaningful for optical discs. According to this answer, only the BIOS LBA read function works, (AH=42h), not the legacy CHS function (AH=02h). So the BIOS doesn't need to invent a fake CHS geometry to give access to the purely linear sectors.
Related: