The Display Tape Status macro provides the status of the specified tape or
the module queue length of a specified active tape.
Format
- label
- A symbolic name can be assigned to the macro statement.
- NAME
- Specifies the symbolic general or real-time tape name. It can
be:
- ccc
- A 3-character string representing a symbolic general or real time tape
name. The first two characters must be alphabetic, and the third
character must be alphabetic or numeric.
- (Rn)
- The number of a register containing a pointer to the symbolic real-time
tape name. n must be a decimal number from 0 through 7, 14, or
15.
- STATUS
- Specifies status of the tape. It can be:
- A
- For an active tape.
- S
- For a standby tape. Do not code S with the option
FORMAT=QUEUE.
- LEVEL=Dn
- A symbolic data level (D0-DF) must be specified.
- FORMAT
- Specifies the information returned. It can be:
- TPIND
- Returns the status of the tape.
- QUEUE
- Returns the module queue length of the tape.
The default is FORMAT=TPIND. The STATUS=S and
FORMAT=QUEUE options are not allowed to be specified in the same
macro call.
The following macro format is still supported:
Notes:
- tapename
- status
- data_level
- label
- A symbolic name can be assigned to the macro statement.
- tapename
- A 3-character symbolic tape name must be specified as the first
parameter. This parameter is required. There is no
default.
- status
- Active or standby status must be specified as the second parameter.
This parameter must be coded as either A or S. This parameter is
required. There is no default.
- data_level
- A symbolic data level (D0-DF) must be specified as the third
parameter. This parameter is required. There is no
default.
Entry Requirements
R9 must contain the address of the ECB being processed.
Return Conditions
- Control is returned to the next sequential instruction.
- The contents of R14 are unknown.
- R15 will point to the Tape Status Table entry of the tape name
specified.
- The contents of all other registers are preserved across this macro
call.
- Certain information from the tape status table is placed in the file
address reference word (FARW) on the level specified by this macro.
For FORMAT=TPIND, the information is in the following form:
CE1FAx
|
Byte 0
Byte 1
Bytes 2-3
|
Status indicators
Tape chain field
Device address
|
CE1FMx
| Byte 4
| Status indicators
|
CE1FCx
| Bytes 5-7
| Tape name
|
The bit meanings of the first byte of status indicators are as
follows:
- Bit
- Meaning
- 0
- Inhibit I/O for device
- 1
- Inhibit queue restart
- 2
- Auxiliary queued
- 3
- Standby tape
- 4
- Tape is reserved
- 5
- Undefined
- 6
- Offline
- 7
- Closed
The bit meanings of the fifth byte of status indicators are as
follows:
- Bit
- Meaning
- 0
- Undefined
- 1
- Undefined
- 2
- Tape contains user labels
- 3
- Backward tape switch in progress
- 4
- Awaiting tape ready
- 5
- Not first volume
- 6
- Input tape
- 7
- Labels present
For FORMAT=QUEUE, the information is in the following form:
CE1FAx
|
Bytes 0-1
Bytes 2-3
|
Reserved for IBM
Device address
|
CE1FMx
| Bytes 4-7
| Module queue length
|
Programming Considerations
- This macro can be executed on any I-stream.
- Both keyword and positional parameters may be used in the same macro
call. This practice is not recommended.
- If the tape status table does not contain an entry for the specified tape,
the FARW is set to zeroes.
- Any unused bits in the status indicators are set to 0.
- The 2 bytes of status indicators returned by the FORMAT=TPIND
form of this macro are not necessarily the primary and secondary status bytes
from the tape status table. The definitions of the indicators returned
by this macro will remain constant, while the primary and secondary status
bytes in the tape status table can be redefined.
- The STATUS=S and FORMAT=QUEUE options are not allowed to
be specified in the same macro call.
Examples
None.