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Offset detection using the D8 read command

Posted: Sat Jan 26, 2008 2:17 pm
by Jackal
Today, with the help of Truong Hi, the coder of PerfectRip, we've come up with a better way of detecting the combined read+write offset of a disc. This new method expands upon our previous discovery, and also proves that our current methods of correcting both offsets are correct.

The principle is that, by using the D8 vendor read command on compatible drives, data sectors are read in audio mode and thus become scrambled. The sync remains unscrambled, and its position can be used to determine the combined read+write offset.

Advantages over old method:

- Works on all discs with data tracks
- All data track sectors can be used to detect

Disadvantage:

- It requires a drive that supports the D8 read command. Most Plextor drives (original ones, not rebadged) are confirmed to support this command (755A, 760A, etc).

Software needed:

Px_D8 v1.01A by Truong Hi and Dremora - http://soft.dremora.com/px_d8_1.01A.7z

Usage: px_d8 <drive letter> <LBA sector>

For LBA sector you can just put '0' or any number. If your drive supports the command, it will give you the Combined offset (the offset that is used in EAC for dumping audio tracks).

Precautions:
- If you have a Plextor drive, be sure to update to the latest firmware available for your drive!

Re: Offset detection using the D8 read command

Posted: Mon Dec 19, 2011 10:04 pm
by rcw003
Does anyone know if the newest Plextor drives still support  d8h?  Looking at purchasing a drive to replace one that is dying and was looking at the PX-L890SA.  http://www.newegg.com/Product/Product.a … 6827249066

Thanks

Re: Offset detection using the D8 read command

Posted: Tue Dec 20, 2011 5:01 am
by Jackal
rcw003 wrote:Does anyone know if the newest Plextor drives still support  d8h?  Looking at purchasing a drive to replace one that is dying and was looking at the PX-L890SA.  http://www.newegg.com/Product/Product.a … 6827249066

Thanks
They don't.. PX-760A is the last one that supports it

Re: Offset detection using the D8 read command

Posted: Tue Dec 20, 2011 6:42 pm
by pablogm123
You need a true Plextor drive (Sanyo chipset). For example any PX-7xx, except 740, 750 and 751. Today, Plextor drives are actually others (Lite-On, LG, Pioneer, NEC...) rebranded by Plextor and they doesn´t offer any special feature.

Re: Offset detection using the D8 read command

Posted: Mon Jul 30, 2012 3:12 pm
by MrX_Cuci
Plextor PX-230A does not work with this util unfortunately.

Working Plextor drives (tested by me): PX-712A, PX-116A

Re: Offset detection using the D8 read command

Posted: Thu Aug 09, 2012 4:49 am
by pablogm123
PX-230A drive is based on ALi chipset, and it is a BenQ drive rebadged. It isn't a authentic Plextor drive, and doesn't understand D8 command, packed mode for CD+G and so on. However, it exposes, aparently, very excellent capabilities in error correction with worn discs, better than real Plextor drives. This is the favourite drive of Spoon, the dBpoweramp's developer.

Re: Offset detection using the D8 read command

Posted: Tue Dec 03, 2013 10:05 pm
by Rocket
http://soft.dremora.com/px_d8_1.01A.7z

Link is dead. Please, reupload.

Re: Offset detection using the D8 read command

Posted: Wed Dec 04, 2013 1:22 am
by usurper
Check the Tools of the trade thread, its linked there.

Re: Offset detection using the D8 read command

Posted: Wed Dec 04, 2013 6:23 am
by pablogm123

Re: Offset detection using the D8 read command

Posted: Mon Dec 23, 2013 7:30 am
by Rocket