The Evolution Of Ide (Ata) - ReActiveMicro MicroDrive Turbo Owner's Manual

Before the CAM ATA standard, many companies that followed CDC, such as Conner
Peripherals, made proprietary changes to what had been done by CDC. As a result,
many older ATA drives from the late 1980s are very difficult to integrate into a dual-
drive setup that has newer drives.
By the early 1990s, most drive manufacturers brought their drives into full
compliance with the official standard, which eliminated many of these compatibility
problems.
Some areas of the ATA standard have been left open for vendor-specific commands
and functions. These vendor-specific commands and functions are the main reason it
is so difficult to low-level format ATA drives. To work to full capability, the formatter
you are using usually must know the specific vendor-unique commands for rewriting
sector headers and remapping defects.

The Evolution of IDE (ATA):

 ATA-1 (1986–1994)
 ATA-2 (1996) EIDE
 ATA-3 (1997)
 ATA-4 (1998) Ultra-ATA/33
 ATA-5 (1999) Ultra-ATA/66
 ATA-6 (2000) Ultra-ATA/100
Each version of ATA was backward compatible with the previous versions.
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