<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)