Emerson MVME147 manual Common Command Set And Disk Operation

A

COMMON COMMAND SET AND DISK OPERATION

The format operation may have a defect list, if a defect list is supplied, a new defect list is built below the user supplied defect list with the four byte header as required by the SCSI device. Three defect list types are accepted.

type 0	User list in logical block number.
type 1	User list in head, cylinder, sector within track.
type 2	User list in head, cylinder, bytes from index.

The new defect list is built as following:

Build 4 byte defect list header:

Byte 0	=	00.
Byte 1	=	$80 ORed with bits 6-4 of byte offset $14
		of format packet. These bits give the user
		control certification and primary defect
		list, and stop format on defect list error.
Byte 2	& 3 =	Defect list length.
Byte 4 to n =		Defect entries as needed.
		No conversion is made from one defect
		list type to another type.

If no defects are supplied by the user, a 4 byte defect list header is built.

Build 4 byte defect list header.

Byte 0	=	00.
Byte 1	=	$80 ORed with bits 6-4 of byte offset $14
		of format packet. These bits give the user
		control certification and primary defect
		list, and stop format on defect list error.
Byte 2	& 3 =	00 Defect list length.

The format command descriptor block is built based on the above information regarding defect list, defect list type, the CL bit in byte offset $14 of user format packet, and the interleave from byte offset $0E.

A-6