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TABLE 2-3 (CONT). STATUS BIT DEFINITIONS - WORD 2
Status Condition
Bit
High Density Selected
3
Data Service Rate Error
4
Uncorrectable Character
5
Error
CRC (Cyclic Redun-
6
dancy Check) Error
LRC
(Longitudinal
7
Redundancy Check)
Error
Reserved for Future Use
8
Reserved for Future Use
9
Time Out Check
10
Functionality Not
11
Available
Beginning of Block
12
(BOB) Early
Beginning of Block
13
(BOB) Late
End of Block (EOB)
14
Early
End ofBlock (EOB) Late
15
PROGRAMMING
Definition
Indicates that in a dual-density unit the HI DEN
switch is set to the high-density position. This bit is
not set if high-density is not selected or the unit has
only a single density.
Indicates that during a Read or Write operation,
data transfer to/from main memory and the unit via
the MTC could not maintain the rate in demand.
Either data was lost on input because of failure to
keep up with device demands or data was unavailable
on output when required by the device. The detection
of this error condition does not affect the execution
of the data transfer operation in process.
Indicates that during a Read or Write operation
either a Vertical Redundancy Check (VRC) error
and/or a dropped character error was detected.
In a VRC error, one or more data characters were
detected with incorrect vertical parity. Data character
parity is odd unless bit 3 in the stored configuration
word is set.
In a dropped character error, one or more data
characters following the first contiguous segment of
data characters in the block were not read.
Indicates that during a Read or Write operation
(9-track NRZI only), the tape CRC character failed
to compare with the reconstructed value.
Indicates that during a Read or Write operation, an
incorrect longitudinal parity was detected for any
track read. The LRC character written at the end of
each block will result in even track parity.
Must be zero.
Must be zero.
Indicates that during a Read or Space operation, an
excessive delay prior to detecting a block
has
occurred
and has resulted in a termination of the order. This
delay is equivalent to passing over approximately
25 feet of tape. This bit is also set during a Rewind or
Rewind and Unload operation following an excessive
delay without the device entering a Rewind sequence
or at BOT. Positioning of the tape under the read/write
and erase heads is unknown. Activation of this bit
during a Rewind and Unload operation indicates
that an excessive delay has been detected without
the device entering the offline state.
Indicates for the subsystem specified herein that
the Output Task Word - Read Backwards order is
not available. A termination of the order without
tape motion takes place.
Indicates that the block written on tape was detected
by the RAW circuitry to have begun earlier than
that specified for the selected device.
Indicates that the block written on tape was detected
by the RAW circuitry to have begun later than that
specified for the selected device.
Indicates that the block written on tape was detected
by the RAW circuitry to have terminated earlier
than that specified for the selected device.
Indicates that the block written on tape was detected
by the RAW circuitry to have terminated later than
that specified for the selected device.
2-13
Reset by
Initialize or Output Task
Word command
Initialize or Output Task
Word command
Initialize or Output Task
Word command
Initialize or Output Task
Word command
Initialize or Output Task
Word command
Initialize or Output Task
Word command
CFI0
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