Glossary


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ABA (Absolute Block Access) A method of addressing the Service Area, used when one main module (Dir) is in a certain place, and the rest of modules are located in different places via the Service Area according to Dir.
Adaptives The heads are mounted on the HDA, so when they move it is not a straight line, but an arc.  That is the reason behind read and write components not always remaining above the same track. The size of the microshift varies for heads in a stack; it is included in the HDD adaptive settings. Please see Micro Jogs.
Adaptive data Adaptive Data is microcode which fine tunes the performance of the hard drive. The Read/Write Heads are firmly affixed on the HSA. When the HSA moves the heads into position all heads are not exactly aligned. The Adaptive data will then determine the best positioning of each head to read or write the data on the platters.
ARCO test (Advanced Read Communication Optimization) A set of self-scan tests of Western Digital drives which come in useful during the drive’s repair.

 B

Burn Code Burn resources – the necessary set of test microprograms and modules to pass the Burn test (one of the most common Samsung drives repairing methods) as well as the Main Code portion of a drive’s firmware.

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Burn (also known as Burn-In) test is intended for building the Service Area, configuring adaptive settings, scanning the surface and re-assigning defects. Burn test is the factory procedure of fine-tuning and diagnostics used specifically for the greater part of a drive.

Important note: you can’t get such resources from the drive like a loader at WD drives, it’s a special compiled firmware.

C

Catalog File map A method that allows the building of a Catalog File map for HFS+. Catalog File is one of five HFS+ special files, that describes the directories and file structure of a partition. HFS+ is found primarily on MAC Operating Systems.
Checksum A checksum is a mathematical computation of the contents of a digital file. On hard drives, the checksums are used to protect the service areas from changes. This is especially important for Service Area modules where using checksum we can determine the integrity of the service area
CHS (Cylinder-head-sector) An early method of giving addresses to each physical block of data on a hard disk drive.
COM port (Serial port (Terminal)) A serial communication interface through which information transfers in or out one bit at a time (in contrast to a parallel port).

The PC-3000 uses the COM port to get  access to a drive in technological mode. This is done by using the USB Terminal and connecting it to a hard drive’s service port.

Composite reading When reading the Service Area modules and some have corruption, one can use Composite Reading.  Composite reading will begin reading a module from Head 0 until such a time there is an error. When an error is detected, the PC3000 will then try to read the remaining data from the same module, but from Head 1.  With this method, one could have the ability to recover a functional module from the parts of corrupt modules.
Controller A chip, an expansion card, or a stand-alone device that interfaces with a peripheral device. This may be a link between two parts of a computer (for example a memory controller that manages access to memory for the computer) or a controller on an external device that manages the operation of (and connection with) that device.
Cylinder The concept is concentric, hollow, cylindrical slices through the physical disks (platters), collecting the respective circular tracks aligned through the stack of platters. The number of cylinders of a disk drive exactly equals to the number of tracks on a single surface of the drive. It comprises the same track number on each platter, spanning all such tracks across each platter surface that is able to store data (without any regard to whether or not the track is “bad”). Cylinders are vertically formed by tracks. In other words, track 12 on platter 0 plus track 12 on platter 1 etc. is cylinder 12.

D

Defect A single bad sector or a group of them on a surface that is added into the defect list ( see “defect lists’) and taking part in the Service Area or User data translation, or not added yet and prevented the full access to the surface.
Defect Lists Defect lists are used to introduce the defects, which are then used to construct a logical translation of the drive. 

E

ECC In telecommunication, information theory, and coding theory, forward error correction (FEC) or channel coding is a technique used to control errors in data transmission over unreliable or noisy communication channels. The central idea is that the sender encodes the message in a redundant way by using an error-correcting code (ECC).

In PC-3000 Flash, the Error Correction Code (ECC) is located in the Service Area. We know also that ECC splits a page into ranges – arrays of bytes containing both the EСС and the data protected by the code. A page may contain any number of ECC ranges.

Encryption (Disk encryption) A technology which protects information by converting it into unreadable code that cannot be deciphered easily by unauthorized persons. There are different Encryption one may be confronted with.

Whole Disk or partition encryption can be done to safeguard sensitive data. One may find BitLocker (Microsoft) or FileVault (MAC) encryption on a customers hard drive. PC-3o0o may detect this as a partition, but no file structure can be found and when the sectors are viewed in Hex, it appears to be nonsensical data patterns on the platter.

The other encryption that Data Recovery Experts may be confronted with is when one takes a defective USB only Hard Drive (PCB has only USB port) and places a SATA PCB onto the drive.  When viewing the contents of the drive, they will be encrypted. One only needs to follow the steps posted in the forum to decrypt the drive using PC-3000, so that the data is again accessible. See SED

Express test A test that allows running fast diagnostics of drive surface condition and magnetic heads by the use of the verification command with blocks containing 256 sectors each.

F

FAT (File Allocation Table) A computer file system architecture and a family of industry-standard file systems utilizing it. The FAT file system is a legacy file system which is simple and robust. It offers good performance even in lightweight implementations, but cannot deliver the same performance, reliability and scalability as some modern file systems. It is, however, supported for compatibility reasons by nearly all currently developed operating systems for personal computers and many mobile devices and embedded systems, and thus is a well-suited format for data exchange between computers and devices of almost any type and age from 1981 up to the present.

G

G-List (Grown Defects List) A table of BAD sectors in User Area that have been remapped from reserve area by internal processing of FW. The G-List, as denoted by its name, will grow when defective sectors are found and isolated.
GREP A mode in Data Extractor which allows multiple searching for sectors containing data that comply with the conditions of the regular expressions selected as search criteria. The expression can be modified by the user for searching the hard drive for specific strings or files.

H

Hard reset An ATA command for uploading important Service Area (SA) data from the surface/ROM to the RAM. Performed by PC-3000.
Hardware A physical component of the PC-3000 System which contains the main board (Express / UDMA / SAS) and additional components like wires, adapters etc.
HDD ID A Hard Disk Drive’s (HDD)  factory specification which contains information such as Model, Serial number, Firmware version and capacity.
Head A part of a hard drive which moves above the disk platter and transforms the platter’s magnetic field into electrical current (reading) or electrical current into the magnetic field (writing).
Header A specific signature which is located at the beginning of file or module to identify it. The File Header is located at the beginning of a file and an example of one would be a Word Document my start with DOC signature, or a PDF File will begin with PDF signature.
Heads map A sequential numbering of hard disk heads. Always starts with head 0 which is commonly located on the lowest platter. Head Map can be physical (numbering excludes factory disabled heads) or Logical (from 0 to X). Heads map may be manipulated to gain access to specific regions of the hard drive by turning off or remapping heads.
Hot Swap A method of getting data access on the patient drive by replacing (swapping) printed circuit board (PCB) between 2 drives without powering off the donor HDD PCB.
HSA A Head Stack Assembly. The Head Stack Assembly in the simplest form it consists of a preamp, the Armature which holds the heads and a screw or threads for mounting the HSA to the Hard Drive Assembly (HSA).

L

LBA (Logical Block Address) A method of User Area addressing.
Loader An essential part of HDD/SSD FW which is uploaded into the drive’s RAM by using special features for accessing the Service Area (SA) / User Area (UA).
Log A special text file which stores all actions that were performed by the user in the performance repairing and gaining access to the data of the defective media. This file is . located in Profile folder.

M

Max LBA A logical address of the last block in the User Area.
Media cache A special area which stores a most often addressed data (File system structures, OS important files, etc.) For different drives, MC can be located on the surface or inside NAND chip (SSHD).
MFT (Master File Table in NTFS) A metadata which describes information about files and directories such as location, name, creation date, size etc.
MicroJog A distance between read and write head elements calculated by the manufacturer. Used to slightly move the center of read/write heads over the center of the track for fast and reliable reading and writing. MicroJogs are primarily found in Western Digital Drives.
Microprogram version (FW version) A unique set of firmware parameters which specify how the hard drive should function. It is useful when searching for a donor device, for matching Firmware is a required conditionindication of a good match for a donor drive.
Module A localized part of the Service Area with a specific function(s). Modules can contain unique or non-unique information. For some drives, modules can have internal structure and control sums.

N

NAND-chip An electronic solid state storage medium that can be electrically erased and reprogrammed.
NV-RAM A non-volatile random-access memory that contains unique microcode and retains the information after re-power. NV-RAM is usually used on Hitachi drives.

P

P-List (Primary Defects List) A table of BAD sectors in User Area that have been remapped from reserve area by internal processing of FW. This list (file) is created at the Factory.
PBA (Physical block addressing) A linear representation of sector physical coordinates.
PCB (Printed Circuit Board)  Printed Circuit Board – the main (and necessary) board of a drive.

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When you perform a PCB replacement (one of most common data recovery technicians’ operations) you need be sure that the The Patient ROM will contain this microcode that must be transferred to the new PCB for it to function on the Patient Hard Drive. If the Adaptives are not transferred where required, the HDD will not be able to read the data.

Preamplifier chip (Preamp.) An electronic amplifier that converts the CPU signal to low-voltage HSA signal and vice versa. Preamlifier chips are normally found on the HSA.

R

RAM (Random-access memory) Volital storage. A voltage memory that contains microcode and overlays currently being used. This information clears after a powering off of the drive.
Raw recovery (File carving) A process of recovering files based on headers, footers and internal file structure that is known for Data Extractor. Raw recovery is the most powerful tool for data investigation/recovery.
Readout A re-reading software procedure for sectors with uncorrected ECC errors. It is used to reduce the number of sectors with errors and improve the dump’s quality.
Ready state A state of the drive when the device is able to receive commands, operate and send output commands. Usually, ready state is indicated by means of DRD and DSC status registers.
Recallibration An action of the drive leading to the movement of the head for reading Servo labels and positioning on Track 0.
Registers (ATA standard information) A drive’s register that contains and displays information about the state of the drive (or the drive’s component).
ROM (Read-only memory) A non-volatile memory used in drives (EEPROM type) that contains unique microcode and retains the information after re-power or power off.
ROM adaptives Service Area (SA) A unique part of the microcode stored in ROM with special information that allows to read/write Service Area elements properly.
ROM module A localized part of the ROM with the specific function(s). Modules can contain unique or non-unique information. ROM Modules are used to build the ROM in case of error.

S

Service Area (SA) Adaptives A unique important ROM module with special voltage and settings for reading the density of Service Area (SA) data.
Service Area (SA) Translator A unique important ROM module. Modern drives can have defects in the Service Area as result, for correct reading the Service Area (SA) needs to use the Translator for Service Area.
Sector A basic data unit. 1 sector = 512 bytes of data.
Self test An internal drive’s test that is used in drive’s repairing procedure (not for data recovery!). All user files are lost as a result!
Servo labels The most powerful signal on the platters surface. At the Recalibration step Microprogram uses Servo labels to detect the read/write heads position over the platters.
Single defect A single sector that сan’t be read.

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If detected, its position will be added to the relocation list and after this ( If the situation repeats ) G-List . This is done to ensure that the drive will not put any data into this sector and the sector will be out from the translation.

Sleep An E6h (“Stand by”) ATA system command which stops rotation of the drive spindle. It’s used in the “Hot Swap” method.
Slider The Read/Write Heads of the HSA are very small. They are so small that they must be mounted on a Slider, which in turn is mounted on the Head Arms. Also ( for some families) we can use the slider’s pattern ( can be seen via microscope) to identify if the heads of donor are compatible.)
Slow responding A common issue of WD Marwell drives. 32 Service Area (SA) module (this is the module that contains the relocation information) gets corrupted or overfilled, so the drive stops to function or functions very slowly.
SMART A special microcode mechanism (Self-Monitoring, Analysis, and Reporting Technology) which calculates and reports different HDD parameters overwatching the ‘drive’s health’ (operation hours, number of power on, average temperature etc).
Soft reset An ATA command for reloading some of the important Service Area (SA) data from the surface/ROM to the RAM by the drive’s own mechanism.
Spindle An axis on which the platter(s) is held.
Spindle motor chip A chip on the PCB which controls the speed at which the platters will spin.
Stand by An E6h (“Sleep”) ATA system command which stops rotation of the drive spindle. It’s used in the “HotSwap” method.
System file A part of the Service Area. System files are Super-files that contain few modules inside. Damage to one module means a whole System file gets damaged. Used only in Seagate F3 drives.

T

Track defect A whole track which can’t be read. It should be hidden into the Defect list
Translator A special microprogram mechanism which converts physical address to logical address and conversely.
Translator recovery A procedure for fixing damaged Translator.
Translator regeneration An extended procedure used to fix a damaged Translator

V

Voltage control A manual voltage selection procedure for every page which contains uncorrected ECC errors with subsequent re-reading. This is used primarily in the PC-3000 Flash