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Format
Function
Address Bus
0 7 8
1718
23
Causes the referenced channel's Status Word 1
to
be transferred
to·
the requesting channel. During
the Response cycle (Second Half Read), the MTC
will return in bits 8-23 of the Address Bus the same
data that was received in bits 0-15 ofthe Data Bus
during the Request cycle. Bits 0-7 of the Address
Bus and the parity bit associated with these bits are
the same data received during the Request cycle.
See Table 2-2.
Channel Number
(Device)
Request
Data Bus
{
I
Not Used
I
Cycle
-"O~=::::n=;::::----,9~IO~
_ _
.!.:15~
I
I
diannel Number
I
I
L-==:l!(C~P)=_l:=====.J
Address Bus
{
'
Not Used
[
Chann(~~umber
Response
Cycle
Data Bus
0123456789101112131415
1718
23
,
,
Corrected Media Error
Tape Mark Detected----'
B O T - - - - - - - - . J
E O T - - - - - - _ - - '
Status Condition
Device Ready
Attention
Retryable Media Error
Re~rved
for Future Use
Corrected Media Error
Tape Mark
PROGRAMMING
Uncorrected Memory Error
Bus Parity Error
Nonexistent Resource Error
- - - Corrected Memory Error
'----Operation Check
' - - - - - R F U - MBZ
' - - - - - - N o n Retryable Error
'------Unequal Length Check
Bit
o
1
2
3
4
5
TABLE 2-2; STATUS BIT DEFINITIONS - WORD 1
Definition
Unit is online with tape loaded, is not rewinding,
and no further manual intervention is required to
place it under program control. This bit will be zero,
if either Status Word 2, bit 0 is a zero or Status Word 2,
bit 1 is a one.
Indicates an event has occurred at the unit which
requires software action. This event, moreover, was
not related to a current task, but rather was
unsolicited. This bit will be set whenever the device
changes its ready condition as a result of a non-
software initated command (Le., enter or leave the
online state, rewinding state, or media loaded
state). Attention status may occur following a soft-
ware initiated Stop I/O or initialize command if the
device was performing a Rewind or Rewind and
Unload Instruction. Whenever the Attention bit is
set, an interrupt is attempted (if the interrupt level
is nonzero). If a previously initiated operation is in
progress when a device state change is sensed, the
resultant interrupt (with the Attention bit set) will
serve as notification of both the end of the operation
and the device state change.
Indicates a data error has occurred and will be set
whenever Status Word 2 bit 4, 5, 6 or 7 is active.
Must be zero.
Indicates an error condition was detected on tape;
however, the data read is not lost. For this sub-
system, the detected condition is a noise area within
an interblock or BOT gap. A noise area may com-
prise 1 to 11 detectable frames of magnetic transitions
on the media when the subsystem is functioning in
the minimum data block mode. In the nonminimum
data block mode, all detected frames of magnetic
transitions are processed as a block.
Indicates a Tape Mark has been detected during the
execution of a Write Tape Mark, Forward-space
Tape Mark, or a Backspace Tape Mark order. This
status bit will also be active ifthe block encountered
during execution of a Forward-space/Backspace/
Read block instruction is a Tape Mark.
2-10
Reset by
A change in condition
Initialize, Input Status
Word 1, or Output Task
Word command
Initialize or Output Task
Work Command
Initialize or Output Task
Word command
Initialize or Output Task
Word command
CFI0
-
~/
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