Honeywell MTU9104 Operation Manual page 18

TABLE 2-2 (CONT). STATUS BIT DEFINITIONS- WORD 1
Status Condition Bit Definition
Reset by
BOT (Beginning of Tape) 6 Indicates the BOT marker is positioned at the BOT
(
sensor. A backspace or rewind order issued to a unit
with tape at BOT will result in no tape motion
initiated and a normal termination of the order.
EOT (End of Tape)
7
Indicates. the EOT marker is positioned at, or has
passed beyond, the EOT sensor. This status bit will
remain active until the EOT marker passes back
over the sensor as a result of a Tape Backward
Motion command (e.g., backspace, rewind). The
state of this status bit has no effect on forward
motion commands, except the Forward-Space to Tape
Mark in which forward motion is terminated in the
next interblock gap.
Unequal Length Check 8 Indicates that for the previous Read operation, the Initialize or Output Task
physical block was either greater or less than the
Word command
value in the range register, at the beginning of the
Read operation. This bit, a 1 and a residue in the
range register, indicates that a short block was
transferred. This bit active and a range register
contents of zero indicate that a long block was
transferred.
Non-Retryable Error
9 Indicates that the position of media under the tape Initialize or Output Task
read/write and erase heads is unknown. This bit Word command
will be set when a write order RA
wa
failure occurs
(i.e., the detection of magnetic transitions on tape
before the start or following the completion of a
recorded data block or the failure to detect magnetic
transitions in the area where a data block is being
written or the failure
to
detect an NRZI density
identification area on tape when writing an NRZI
tape). This bit will also be set when an erase order
(
RAW failure occurs (Le., the detection of magnetic
transitions in the area on tape being erased) or
when, during a read order, a split block is detected.
A split block is a data block in which its beginning
and end positions cannot be guaranteed detectable
because of a detected unrecorded area within the
block. This status bit also becomes active when
Status Word 2 bit 10 (Time Out Check) is set.
Reserved for Future Use
10
Must be zero.
Operation Check
11 Indicates a write type order (Write, Write Tape Initialize or Output Task
Mark, Erase) was issued to a tape drive in Write Word command
Protect (see state of Status Word 2 bit 2); that upon
acceptance of an Output Task Word data transfer
command, the direction of data transfer is not the
same as that specified by the direction bit of the
channel number issued by the previous Output Address
command; that upon acceptance of an Output Task
Word data transfer command, the contents of the
range register is zero (for Read or Write) or less than
18 (for write) when the subsystem is in the ANSI
configuration mode; or that a command (other than
No Operation) was issued to a channel on which the
device is in the offiine or Not Ready state.
Corrected Memory Error 12
Indicates that during execution of the previous Initialize or Output Task
operation, main memory detected and corrected a
Word command
memory read error. The data that was delivered to
the MTC was assumed to be correct.
(
PROGRAMMING
2-11 CFI0