Viper 60s Theory Of Operation And Maintenance Manual page 117

VIPER SCSI COMMANDS
5.21.4 MODE SENSE Header Data
Fiel~J?~s~r!p~i0!l~~_~
__ . . __
.~_
. .
_~
__ _
I
BIT
I
NAME
i
BYTES BITS DESCRIPTION
!
Sense Data
Length
Medium Type
WP Bit
Buffered
Speed
o
2
2
2
Block Descriptor 3
Length
7
4to 6
o
to 3
5-59
This field specifies the number of bytes in the
following MODE SENSE data. The Sense Data
Length does include itself and is always set to
OBh.
This field is always set to zero indicating default
media.
This bit indicates whether or not the tape is write
protected; a one indicates write protected, a zero
indicates write enabled.
In Unbuffered Mode the Viper drive does not
report Good Status on a WRITE command until
the data has been successfully written to tape.
In Buffered Mode, the drive reports Good Status
on a WRITE command as soon as the data has
been written to the Viper buffer. The following
table describes the buffered mode field status
and interpretation.
The Speed Field is always be set to zero to
indicate that the default speed of 90 ips is selected.
Block Descriptor Length field is always set to 08h
indicating that there is one 8 byte Block Descriptor
to follow.