A brief description of how EIDE-(ATAPI) allows communication between a host computer and a hp dvd-writer dvd100i drive is provided in this chapter.
This chapter is organized as follows:
ATA/ATAPI | p. 31 |
IDE Connectors | p. 31 |
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ATA/ATAPI
Prior to the introduction of CD-ROM drives, the standard interface used inside personal computers was the AT Attachment (ATA) interface (also referred to as the IDE interface), which was used to communicate with hard disk drives. The ATA standard allows two devices to exist on the same bus, with the primary device being named Device 0 or the Master, and the secondary device being named Device 1 or the Slave. The ATA standard defines both the low level hardware requirements such as required device registers, electrical signal specifications, cabling and connector specifications, and the higher level ATA command set which provides a mechanism for a computer to communicate with a device.
When CD-ROM drives were introduced, new requirements were set which could not be met with the existing ATA command set. Therefore an extension of the ATA protocol was created. This new protocol was named ATA Packet Interface (ATAPI). The ATAPI command set was based on the existing SCSI command set, and by design allows ATAPI and ATA devices to coexist on an ATA bus. Due to wide availability and low cost, the ATAPI interface has become the standard for CD-ROM drives used in PCs. However, since the newer MMC specification includes the majority of the packet commands which are in the ATAPI specification, the MMC specification is used as the primary reference for most commands, and the ATAPI specification is used as the primary reference for lower level communication protocol details. The hp dvd-writer and is designed using the ATA-2 version of the ATA specification, and the ATAPI 2.6 version of the ATAPI specification.
