Seagate 810 manual Word Bit Description if bit is set to

Marathon 810 (ST9816AG) Product Manual, August 1995		27
Word	Description	ST9816AG
67	Minimum PIO cycle time without IORDY flow	016BH
	control (363 nsec)
68	Minimum PIO cycle time with IORDY flow	0078H
	control (120 nsec)
69–127	ATA reserved	0000H
128–159	Seagate reserved	xxxxH
160–255	ATA reserved	0000H

Note. DMA mode settings in the Identify Drive command are reflected in the bit settings for words 62 and 63, as shown below.

Word	Bit	Description (if bit is set to 1)
62	0	Single-word DMA mode 0 available
62	1	Single-word DMA mode 1 available
62	2	Single-word DMA mode 2 available
62	8	Single-word DMA mode 0 currently active
62	9	Single-word DMA mode 1 currently active

6210 Single-word DMA mode 2 currently active

630 Multiword DMA mode 0 available

63	1	Multiword DMA mode 1 available
63	2	Multiword DMA mode 2 available
63	8	Multiword DMA mode 0 currently active
63	9	Multiword DMA mode 1 currently active
63	10	Multiword DMA mode 2 currently active