Bitfields for DOS 4.0-6.0 disk buffer flags:
Bit(s)	Description	)
 7	remote buffer
 6	buffer dirty
 5	buffer has been referenced (reserved in DOS 5+)
 4	search data buffer (only valid if remote buffer)
 3	sector in data area
 2	sector in a directory, either root or subdirectory
 1	sector in FAT
 0	reserved
SeeAlso: #01651