Parallel ATA

Advanced Technology Attachment ( ATA short ) is a standard for parallel data transfer between storage media and drives, and the corresponding port of a computer as it is used in the (E) IDE connection.

Advanced Technology Attachment with Packet Interface ( ATAPI short ) uses this physical interface and extends the protocol of the data interface so that also encapsulated SCSI packets can be transmitted. The resulting possible SCSI commands extend the range of ATA on the originally pure disk mode also. So even devices such as removable drives, optical drives, and tape drives can also be used with ATAPI.

Integrated Drive Electronics ( IDE short ) is a physical data line, which is controlled by IDE controllers. The first generation of PCs (from about 1984) had no built-in control unit - it had to be retrofitted via buses (ISA, PCI, etc.). Some sound cards were equipped with an IDE controller, the at least one IDE socket had ( for one or two devices). EIDE ( = enhanced IDE ) is the name for two controllers with four data lines. The IDE controller of sound cards were usually only compatible with certain devices, such as CD -ROM and DVD drives. Separate control units were required for IDE hard drives and IDE tape drives. Later, the IDE controllers were placed directly on the motherboard and replaced gradually by SATA controllers from around 2005. However, there are special IDE RAID controller in the form of expansion cards for PCI slots on the motherboard.

The ATA standard was developed by the T13 Technical Committee of the InterNational Committee for Information Technology Standards ( INCITS ) and adopted by the American National Standards Institute ( ANSI) as American Standard. The first standards ATA - 1 to ATA -3 were enhanced by the ATAPI standard, in order to transmit SCSI commands using the Packet command of the ATA protocol can. This led to the naming ATA/ATAPI-4 to ATA/ATAPI-7; see section versions of the ATA standards.

The T13 committee in early 2010, as T10 a year earlier, blocked public access to all documents. Older documents can still be accessed via the old links.

Besides these version names exist for certain ATA / ATAPI versions synonyms such as Fast ATA and Ultra ATA, in order to highlight the speed especially against ATA -1 to ATA -3. Meanwhile, the term parallel ATA ( PATA, also P -ATA) is used synonymously for all ATA variants and the (E ) IDE interface to basically differentiate this from SATA. PATA interfaces in a modern computer so ensure their compatibility with components such as DVD burners or super floppy drives, have the older connections.

• 3.1 ATA -1 (1989-1999, ANSI X3.221 - 1994)
• 3.2 ATA-2 (1994-2001, ANSI X3.279 - 1996)
• 3.3 ATA -3 (1996-2002, ANSI X3.298 - 1997)
• 3.4 ATA/ATAPI-4 ( 1997-2008, ANSI NCITS 317-1998 )
• 3.5 ATA/ATAPI-5 (since 1999, ANSI 340-2000 NCITS )
• 3.6 ATA/ATAPI-6 (since 2000, ANSI 361-2002 NCITS )
• 3.7 ATA/ATAPI-7 (since 2001, ANSI INCITS 397-2005 )
• 3.8 ATA -8 (since 2005, ANSI INCITS 452-2008 )
• 3.9 ACS-2 (since 2008), ACS -3 ( since 2011 )
• 3:10 compared

History

The U.S. hard drive maker Western Digital was commissioned in 1984 by Compaq to develop a hard disk controller. In contrast to the ATA predecessors ST506 ( with the recording method MFM or RLL ) and the Enhanced Small Disk Interface ( ESDI ) communication over a single 40 - pin flat cable should be done and a larger share of the controller electronics on the peripheral ( z. , hard disk).

Western Digital called this interface Integrated Drive Electronics (IDE ) ( 1986). In cooperation with other hard disk manufacturers has been established as a common standard, which was adopted in 1989 as ATA -1. To date, the term "IDE " is a synonym for " ATA " or today " PATA ". The term AT implied nor on the IBM PC / AT (Advanced Technology ) back with 80286.

Western Digital expanded and improved this standard with new features. The marketing name for EIDE "Enhanced IDE " (corresponds to ATA -2) was created and has since been commonly used as a generic term for all the improvements of the IDE. In fact, there are a variety evolved specifications (see below).

In the ATA / ATAPI interface, the connected devices have its own controller. With this built-in controller to communicate with the host ( via a host adapter, such as an interface card ). ATA / ATAPI device is using a ribbon cable connected to the 40 - pin interface of the host ( ATA -40). Two units per connection are possible, these are referred to here as Device 0 (also Master, MA) or device 1 ( slave also, SL ). Usually Device 0 is connected at the end of the cable. The setting of the Device 0 or 1 status is usually done via jumper. On many devices, there is also the possibility of " Cable Select " (CS). For this purpose, both devices must be set to CS, with a special connection cable award the device 0 or 1 status.

Put simply, ATAPI describes a method to transmit ( a subset of ) SCSI commands (s ) via the ATA interface. In fact sets ATAPI so on ATA. Since these are, however, described since ATA/ATAPI-4 in a common standard ATAPI is commonly used the term ATA /.

For the nomenclature

As indicated in section history, the transition from the industrial standard for an official standard was only after quite some time ATA devices were prepared: The final draft of the standards body, T13 Technical Committee for the ATA -1 standard is dated 1994, although ATA devices are manufactured since the mid- 1980s. Therefore, had already prevailed at the time of publication of the official standards master and slave as a common expression of the two from an ATA port addressable devices. From a technical perspective, however, these names do not appear justified, since the activation of both devices by the host (usually a computer ) are practically equivalent. The publications of the T13 Technical Committee instead use the terms Device 0 and Device 1 to the technological realities rather bill. In its current condition, this article uses the nomenclature of the T13 Technical Committee to reflect the resulting given official line, followed by the master or slave in brackets in order to preserve the general intelligibility.

Special form

ATA 44: For laptops, there are special forms of the interface that also transmit audio signals in addition, the supply voltage ( 5 V) and optical drives. These are called 2.5 "hard drives ATA -44 and optical SlimLine drives ATA 50. ( The number indicates the number of plug-in contacts to. )

ATA ZIF: For used in media players 1.8 "hard drives, there is a special form with 40-pin socket. It is however also used in UMPC and some notebooks.

Versions of the ATA standards

If two devices with different versions ATA connected to the same cable, decides in older controllers, the slower device on the speed of both devices. Modern ATA controller ( since about 1998), the speed for each device separately control so slow devices no longer slow down the entire bus.

ATA - 1 (1989-1999, ANSI X3.221 - 1994)

ATA - 1 operates asynchronously.

Use find several PIO modes (Programmed I / O) and DMA ( Direct Memory Access) variants:

• PIO mode 0: 3,3 MB / s; PIO 1: 5,2 MB / s; PIO 2: 8.3MB / s
• Single Word DMA mode 0: 2,1 MB / s DMA single 1: 4,2 MB / s DMA single 2: 8.3MB / s
• Multi Word DMA mode 0: 4.2 MB / s

ATA - 2 (1994-2001, ANSI X3.279 - 1996)

The control and data signals may be transmitted synchronously with the ATA -2. Efficiency up to 16.6 MB / s New transmission modes: block transfers, Logical Block Addressing.

• PIO Mode 3: 11.1 MB / s; 4 PIO 16.6 MB / s
• DMA mode 1: 13.3 MB / s Mode 2 (DMA 2): 16.6 MB / s (from here always Multiword )
• Fast ATA include ATA -2, 3 PIO, DMA 1
• Fast ATA -2 ATA-2 includes, PIO 4, DMA 2

ATA - 3 (1996-2002, ANSI X3.298 - 1997)

ATA - 3 has over its predecessor ATA-2, two new functions: SMART and the Security feature set. Performance and transmission modes have not changed compared to ATA -2.

ATA/ATAPI-4 ( 1997-2008, ANSI NCITS 317-1998 )

With ATA/ATAPI-4 CD -ROM drives and CD burners are first incorporated into the standard. Purpose, the standard was first mentioned ATA / ATAPI, which stands for ATA Packet Interface. The Packet Interface defines a layer in order to send SCSI commands over the ATA protocol can. Capacity: 33.3 MB / s It introduces a new mode called Ultra - DMA ( UDMA ). ATA/ATAPI-4 is however compatible to the old modes PIO and DMA.

• With the UDMA standard to the Cyclic Redundancy Check has been extended.
• Ultra DMA mode 0: 16.7 MB / s; UDMA 1: 25.0 MB / s UDMA 2: 33.3 MB / s
• Ultra ATA/33 is a common abbreviation of ATA -4 with UDMA 2

With the Host Protected Area feature (HPA ) a protected area can be created on the disk.

ATA/ATAPI-5 (since 1999, ANSI 340-2000 NCITS )

ATA -5 includes a new mode: Ultra DMA 4 performance 66.6 MB / s, therefore also called UDMA -66 (UDMA 3: 44.4 MB / s). For the ATA - 5 standard, a special 80 -wire cable is required. While it still has only 39 connector pins, but there are 41 additional lines with ground connection between each of the data lines. These provide for a defined wave impedance of the signal lines to reduce reflections. Furthermore, they reduce the crosstalk between the signal lines. Both could otherwise lead to transmission errors.

ATA/ATAPI-6 (since 2000, ANSI 361-2002 NCITS )

With ATA - 6 and the mode Ultra DMA -100 ( UDMA 5 ) are possible data rates up to 100 MB / s. Therefore, it will also provide the name often ATA/100. Also new ATA commands were introduced, 48-bit addresses allow large sector (LBA -48 ), which is the maximum addressable capacity of 228 x 512 bytes = 128 GiB 248 x 512 bytes = 134,217,728 GiB ( ≈ 144 115 188 GB) = 128 PiB increases.

Another new feature is Automatic Acoustic Management (AAM ).

The Device Configuration Overlay (DCO ), it is possible to affect certain reported values ​​in the Identify information of a disc. For example, the feature bits for individual DMA modes, SMART features, AAM or HPA disabled or the reported size of the disk can be reduced. Using hdparm originally developed for UNIX systems System program, for example, this information with sudo hdparm - dco -identify / dev / be queried at a specific hard drive.

ATA/ATAPI-7 (since 2001, ANSI INCITS 397-2005 )

With ATA/ATAPI-7 is the first time a distinction between parallel and serial transmission and the common command set (ATA / ATAPI Command Set, ACS) in the standard. Retronym was the previous standard called PATA (Parallel ATA) and the serial version of SATA.

With the PATA mode Ultra DMA -133 (UDMA 6) are possible data rates up to 133 MB / s. Therefore, it will also provide the name often ATA/133.

ATA -8 (since 2005, ANSI INCITS 452-2008 )

With ATA -8 bugs were fixed and restructured the standard. He is also compatible with previous versions. What is new about that ATA -8 is divided into four documents, the Architecture Model ( ATA8 -AAM ), the Command Set ( ATA8 -ACS ), the parallel transport ( ATA8 -APT ), and finally the Serial Transport ( ATA8 - AST). This allows a further abstraction of the definition of the commands of Architecture Models and finally transport. The command set ATA8 -ACS was published in September 2008 as ANSI INCITS standard.

Was deleted, inter alia, a chapter on the definition of Festplatten-/Controller-Register from official was allowed to announce: " ATA8 -ACS is documenting the command set and not the transport". Another interesting observation is that really the software protocol is abstracted with the technical hardware implementation. Has been in ATA/ATAPI-7 Volume 1 (corresponding Command Set and Architecture Model ) nor repeatedly pointed out that the SATA interface is a partial other programming / transmission as the PATA interface (see IDE ) that such references appear in ATA -8 no longer on, but many passages were removed and swapped in ATA8 -APT and ATA8 - AST. Their intention is to step into the future go, because in the system programming dominated until now only the PATA drives while on SATA was great confusion.

For the first time there is a standard way, the current temperature, minimum and maximum values ​​and read the temperature history of the last hours of operation of the SCT Commands. Hard drives with this feature have been available since 2006. Although the actual temperature could be determined as SMART attribute so far mostly, but that was not part of the ATA standard.

ACS-2 (since 2008), ACS -3 ( since 2011 )

Following the publication of ATA8 ACS standards, the development of the command statement under the name ACS - 2 occurs, since 2011 under ACS - third The final ACS-2 revision has not yet been published as an official ANSI INCITS standard.

A new feature of ACS-2 is "Device Statistics". Herewith values ​​such as operating hours, number of resets, number of read and write operations, number of errors and the temperature can query. In contrast to the SMART attributes, the importance of all the values ​​is standardized.

Comparison

All new versions are backward compatible to ATA/ATAPI-4: newer hard drives can therefore also be used on older computers, older drives are also connected to newer interfaces.

Addressing problems

Older ATA controller or older system software can often respond disks only up to a certain capacity. This can optionally be used only part of the disk capacity. Typical limits are 504 MiB, 8 MiB, 32 MiB, 128 GiB. The 128- GiB - limit results from the use of 28-bit LBA, because 28-bit can not be more than 228 sectors ( corresponding to 128 GiB ) address. There is the extension to 48-bit LBA, which considerably extends the address space. The other limits are established by the CHS addressing, so by the division into cylinder, head and sector - which here apply their own limits for each value, and the CHS addressing was already obsolete at the first standard of X3T10. Even today use many system programs - such as boot manager or partitioning tools that load during start up - CHS addressing.

Remedy modern hardware and software. So BIOS updates were issued in the past often fix these problems. By today's standards, and software implementations addressing problems are practically become a thing of the past.

By the MBR partition table using classic drives in systems on a 2 TiB limit that can be " bypassed " only by using the EFI GUID Partition Table is limited. The 2- TiB limit is caused by the 32 -bit size of the sector information in the partition entries.

A simpler way to get around the 2- TiB limit is to increase the size of the data blocks to 1024 bytes or 2048 bytes, which increases the addressable area on 4 TiB or TiB 8. However, this also reduces the smallest possible cluster size to 1024 or 2048 bytes, but this is of little relevance, since cluster sizes are in any case hardly used under 4096 bytes.

Password protection

Most currently available on the market ATA and Serial ATA hard drives have a 32 -byte password protection with General and user keys without the can not access the data on the hard disk. A running with system privileges program can set a password and make the user the data inaccessible.

The Security feature set has been used by IBM in 1998 for the first time outside of notebooks and reached broad application, since Seagate shipped 3.5 "hard drives for the Xbox.

The hard drives also allow you to avoid setting a new password. However, this function must be called at every system startup. The BIOS can be done before the start of the operating system, which is only supported by a few BIOS. During the boot process, an additive tool can be opened which seals off the hard drive.

Pin Assignment

The ATA connector (ATA -40 ) is a 40 -pin dual row connector, Pitch 2.54mm ( 100mil ):

When the drive connector (top view of the pins)

39________ ________ 1 odd pin numbers    | · · · · · · · · · · · · · · · · · · · · |    | · · · · · · · · · · · · · · · · · · · |    40 ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ 20 (Key) ¯ ¯ ¯ 2 straight pin numbers Female connector on the cable (top view, from the front)

1________ - ________39 odd pin numbers    | OOOOOOOOOOOOOOOOOOOO |    | ooooooooo oooooooooo * |     2 ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ ¯ 40 straight pin numbers In a correctly wired ribbon cable pin 1 is on the color ( usually red ) marked vein. As an additional security to the socket for pin 20 ( marked in the image with a * ) is closed in many connectors to prevent incorrect plugging. When plug with center groove are now not only in the drives themselves, but also on controllers and motherboards standard. Since the female connector has a nose at the corresponding point, a polarity reversal is ruled out.

In ATA -44, which is often used for 2.5 "hard drives are used, the pin spacing is reduced to 2.00 mm. The assignment corresponds to ATA - 40, but here the power supply through additional pins on the ATA connector is made.

ATA cable: color of the plugs

With the newer 80-conductor ATA -5 cables, the plugs have three colors:

Blue: controller / PC Gray: Slave (Device 1 / IDE 1 ) - 79 cores: Master / Slave signal line 28 cut / interrupted Black: Master ( Device 0 / IDE 0) This is important for:

• Fast UDMA modes: from UDMA -66 ( UDMA 4), the finer, 80-conductor ribbon cable used in which every second conductor is connected to ground, what the signal conductors against each other shields and makes the higher speed possible. The plugs have as usual 40-pin host adapter - side plug has, however, a special coding ( PDIAG is separated and placed in the host adapter, a capacitor with a certain value to ground) where the ATA host adapter can be seen that this type of cable is used. Only then the host adapter unlocks the faster modes of 66 MB / s and higher. When connecting the ATA device with such a cable is therefore important to note that the blue end of the cable must be connected to the motherboard or the ATA host adapter.

• Cable-Select: For some time now support ATA cable, the Cable-Select Addressing and have to plug in gray and black, to which the ATA devices to be connected. Is addressed in the Cable Select method, device Device is the black connector automatically 0 (master) and the device at the gray connector device 1 (slave). The signal line 28 is connected only to the master, not the slave. To use this method, both must ATA / ATAPI devices to " CS " be jumpered. Otherwise, that is to change the configuration of a device to " master " and the other to " slave "; with manual jumpering it does not matter which one is black and which is connected to the gray connector. If only a single ATA / ATAPI device connected to the cable that plugs into the middle of the cable must necessarily be released as an unassigned end of the cable can cause interference. Under circumstances the Cable Select process is not desirable.