Maxtor 10K III manual Read Buffer Command-Field Descriptions, 0010b, Multiple

			SCSI Description
			READ BUFFER Command-Field Descriptions
	Table5-130
	Four modes are supported by the drive; Combined Header and Data, Data Only, Descrip-
Mode(KGNF￿	tor Only, and Read Data from Echo Buffer&GUETKRVKQP. The permissible values for Buffer ID, Buffer
	Offset, are as follows:
	Combined Header and Data – In this mode, data to be transferred is preceded by a 4-
	byte header that contains the buffer capacity. The resulting descriptor and data are trans-
	ferred to the initiator during the command’s data-in buffer transfer.
0000b	must be 0
		must be 0
	Allocation length must be set to between 0 and 516 (4 bytes of header and up to 512
	bytes of data).
	Data Only– In this mode, the data-in buffer transfer contains data from the controller’s
	memory+&.
	. When non-zero, the value specifies a specific track line in the controller’s
	cache. If Buffer ID of zero is specified, the buffer referenced is the same as if a Buffer ID
0010b	of$WHHGTone￿were specified.
		. When non-zero, the value of Buffer Offset can range from 0 to one less
	1HHUGV
	than the number of sectors/track multiplied by 512. This value must be either a zero or
	a multiple of 512.
		Must be between zero and the maximum number of sectors/track mul-
	#NNQECVKQP+&1HHUGV￿￿.GPIVJ￿￿
	tiplied by 512.
	Descriptor Only
	When requesting a descriptor (a description of the buffer referenced in the Buffer IDfield),
	the resulting data is the offset boundary requirements and the length of each buffer.
	When non-zero, the value specifies a specific track line within the controller’s
0011b	cache. If Buffer ID of 0 is specified, the buffer referenced is the same as if a Buffer ID of
	1$WHHGTwere￿specified.
	1HHUGV￿Must be zero
	#NNQECVKQP+&￿￿.GPIVJ￿￿		Must be between 4 (header) and the maximum number of sectors/
	track multiplied by 512 + header size.
1010b	Read Data from Echo Buffer
	In this mode, the drive transfers data to the host from the echo buffer. The echo buffer
	will transfer the same data as when the WRITE BUFFER command with the mode field
	set to echo buffer was issued.
	Ignored.
	$WHHGT￿	Ignored.
	1HHUGV		Maxtor Atlas 10K III	5-109