IDE, ATA, PATA and ATAPI interface, what is it and how does it work?

As you realize, on this planet of PC {hardware} interfaces are the connection strategies between parts. For instance, PCI-Express is an interface, as is USB or SATA since they’re methods to attach some parts with others (though it is typically to attach a element to the motherboard).

What is the IDE interface and what does it encompass?

Parallel ATA (PATA), initially AT Attachment and also referred to as ATA or IDE, is a normal interface created by Western Digital and Compaq in 1986 to attach laborious drives and CD / DVD drives to the motherboard of a PC, though it was additionally used a variant to attach floppy drives. The customary is nonetheless maintained by the X3 / INCITS committee and makes use of the underlying ATA and ATAPI (AT Attachment Packet Interface) requirements.

The time period IDE comes from Integrated Drive Electronics, as a result of it was the identify Western Digital gave it when it developed this interface, and storage items with that interface had a most measurement restrict of 137 GB.

IDE interface

Indeed, we’re speaking about that elongated interface with many connectors (39 or 40 relying on the machine) that arduous drives and optical drives of yesteryear had and whose cable was grey, flat and elongated with individually remoted pins. Unlike the Serial ATA customary and as its identify signifies, the connectors work in parallel, which allowed a couple of machine to be linked in a single cable.

Obviously, the motherboards had this 40-pin connector to have the ability to join the cables, which went to the laborious drives and optical drives in the identical means as we now join the SATA information cables. By the best way, these items had the peculiarity that they have been powered by MOLEX 4-pin connectors from the ability provide as a substitute of contemporary SATA connectors.

History and terminology of the IDE interface

The customary was initially conceived as “AT Bus Attachment”, formally known as AT Attachment and abbreviated as “ATA” as a result of its primary function was a direct connection to the 16-bit ISA bus launched by IBM. When the SATA interface was launched in 2003, the unique ATA was renamed Parallel ATA or PATA for brief.

IDE interface

ATA bodily interfaces turned a normal element on any PC, initially in host bus adapters, generally in a sound card, however finally as two bodily interfaces constructed into the motherboard’s SouthBridge. Called “major” and “secondary” or “grasp” and “slave” ATA interfaces, they have been assigned to base addresses 0x1F0 and 0x170 in ISA bus methods.

These are the present sorts or generations:

  • IDE and ATA-1– The first model of what is now often known as ATA / ATAPI was developed by Western Digital. The first gadgets to make use of it have been Compaq and they have been launched in 1986.
  • EIDE and ATA-2– This customary was authorised in 1994, and the EIDE identify stands for Enhanced IDE.
  • ATAPI: Initially the interface was developed for storage gadgets, however ATAPI allowed the ATA interface to be taken additional and utilized in different varieties of gadgets, since it allowed the “eject” command, so it was excellent for floppy drives, for instance. It additionally integrated the SCSI command.
  • UDMA and ATA-4: this customary raised the efficiency to 33 MB / s, and in its newest variations new 80-pin cables have been integrated that elevated the efficiency as much as 133 MB / s.
  • Ultra ATA: Initially described by Western Digital in 2000, this interface described greater efficiency however by no means absolutely noticed the sunshine as a result of it coincided with the times of SATA, which ended up changing the IDE interface.

Master and slave disks, how did they work?

The present SATA interface works in sequence, so it is not attainable to attach a couple of machine with the identical information cable, however the IDE interface, being in parallel, did permit it. Of course, when two gadgets have been linked with the identical cable, one needed to be designated as machine 0 (Master) and the opposite as machine 1 (slave). This distinction was vital to permit each drives to share the identical information cable with out battle, and it was made with the well-known jumper integrated in laborious drives and optical drives of the time.

Device drive 0 is the one that may seem first within the BIOS and will probably be used as well the working system; In different phrases, you might have the working system put in on two laborious drives and change which one as well from simply by altering the place jumper on each drives to pick out a major and a secondary one. This pressured PCs that had an IDE interface and a single laborious disk to have the jumper within the Master place, as a result of in any other case the BIOS didn’t know the place the PC needed to boot from, though that was solved in later variations with a particular configuration known as “Single”.