Bitfields for JAMINFO flags:
Bit(s)	Description	)
 2-0	reserved
 3	(v1.20+)
 4	enable direct write requests (Int 26h, non-DOS requests, etc.)
 5	read-only mode
 6	no write-behind caching
 7	full undelete-compatible allocation strategy
SeeAlso: #02831,#02832