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Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
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Understanding & using DLMCode

October 28th, 2004, 10:02

What is DLMCode ?
What's the diffrences betwen HPA & DLMCode?
10x

October 29th, 2004, 4:41

Why you are asking?

November 1st, 2004, 4:19

I'm interesting because i have a lot of HDDs that are limited using DLMCode. Usualy those are HDDs that are shiped with compaq computers. Example WD200BB is limited to 10Gb!
It's no problem to "unlock" those drives but sometimes I need to lock them because of bad sectors or some other reasons, and no HPA is available for use.

November 3rd, 2004, 7:15

How did you determine that your drives are locked using DLMCode?
And please explain how you unlock them?

November 5th, 2004, 12:42

please ,who does know the problem?????

November 7th, 2004, 15:24

формоцевт: When I start MHDD on "locked" drive, Supported functions are DLMCode LBA AAM DMA (UDMA6,MWDMA2). No HPA notice is shown on top of MHDD. After unlocking drive support DLMCode LBA HPA AAM DMA (UDMA6,MWDMA2)
Therefore i think that DLMCode is the key to hte mystery.

November 8th, 2004, 9:36

OK, your case seems intresting despite at the beginning it looked like one more lame story.
You see, DLMCode = Download microcode. Next: this flag presents both in the locked state and in unlocked state. So explain, why do you think that DLMC affects lock? And it's intresting even more than before: <b>what do you mean saying "unlock"?</b>
My version - drive may be "hardlocked" (aka FirmwareHPA). I don't really know how to do it with WD, even unsure they support this trick. If it's true, locked (modified) firmware may has HPA disabled, and after unlock it enables it.

November 8th, 2004, 15:41

I'm not 100% sure about DLMC.
I meet 2 cases of drives with less space that they should be.
1. Example: Quantum Fireball LCT10 06 (6.4Gb) with stamp on top and other little stamp aside "10.2At......." First i think that this is some kind of mistake because a original stamp says 6,4 and BIOS says 6.4GB. Ok but when I start pc3k the drive have 2 physicaly heads instead of 1! Strange because this LCT10 have one model 5.1GB with one head and other 10.2GB with 2 heads and max LBA 20 044 080. My drive has 12 594 960 max LBA and 2 heads. The only thing in that case to enlarge the capacity was to change the meaning of MAX lba in "паспорт диска" to 20 044 080 and chnage the name from Qunatum Fireball LCT10 06 to .... LCt10 10. :o
Same with LCT15 10...
This look like your version except of disabled HPA.
I suppose that this decreased capacity are caused by need of HDD's that are no longer in productuion, and was made in factory.
2. The case that I described before. Drive is limited somehow. In that case no HPA is available. Usulay that kind of HDD's can be found on COMPAQ SSF, or any other compaq PC's. This drives have model that shows ther real capacity WD200BB, Maxtor 2B020H1, 6E040L0, 6L020J1, 6L020L1 Seagte Baracuda 4. I meet HDDs limited to 3.2 6.4 15 but most often to 10GB.
I'm not sure if this modification is made in the factory or by dealer of those CPQ's to replase deffective ones.
How I "unlock" them. I use one small program that reset HDD. But it work only one way :| :?
One interesting thing is that the program do not affect case one(1). So they use different way of limiting capacity.
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