ATA-4

from The Free On-line Dictionary of Computing (8 July 2008)
ATA-4
UDMA
Ultra-ATA
Ultra DMA

   <storage> /ul'tr* D M A/ (Or "Ultra DMA", "UDMA", "Ultra-ATA",
   "Ultra-DMA/33") A development of the {Advanced Technology
   Attachment} specifications which gives nearly twice the
   maximum transfer speed of the {ATA-3} standard ({PIO} Mode 4).

   ATA-4 Extensions Ultra DMA/33 Synchronous DMA Mode maximum
   burst transfer rates:

   	Mode 	Cycle Time 	Transfer Rate
   		ns		MB/s
   	0 	235 		16
   	1 	160 		24
   	2 	120 		33

   This is achieved by improving timing windows in the {protocol}
   on the ATA interface; reducing propagation delays by
   {pipelining} data transfers and transferring data in
   {synchronous} (strobed) mode.

   Developed by {Quantum Corporation}, ATA-4 has been freely
   licensed to manufacturers and is supported by {Intel
   Corporation}.

   (1998-09-30)