Use this system macro to address a general tape and read or write a single
record into or from a specific storage area using a series of data chained
channel command words (CCWs).
Required Authorizations
|
Key0
| Restricted
| System
| Common Storage
|
| X
|
|
|
Format
- label
- A symbolic name may be assigned to the macro statement.
- NAME
- Specifies the symbolic general tape name. It can be:
- yyy
- A 3-character string representing a symbolic general tape name. The
first two characters must be alphabetic, and the third character must be
alphabetic or numeric. The first two characters cannot be RT.
- (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.
- LEVEL=Dx
- A symbolic data level (D0-DF) must be specified.
- AUTO=NO|YES
- Specifies whether an automatic tape switch occurs for end-of-tape,
end-of-volume, or hardware error conditions.
Notes:
- If the tape is blocked, TPF tape support will force AUTO=YES regardless of
how this parameter is entered.
- If the tape is blocked or AUTO=YES is specified, an end-of-tape or
hardware error from a tape write operation, or an end-of-volume error from a
tape read operation causes an automatic tape switch to occur.
End-of-file and hardware errors from tape read operations do not cause an
automatic tape switch to occur.
- If the tape is not blocked and AUTO=NO is specified, end-of-tape,
end-of-volume, and hardware errors are indicated in the ECB.
- CCW1=NO|YES
- This optional parameter is used to indicate the CCW format in the
specified data level. If CCW1=YES, the CCW is treated as CCW format-1,
otherwise CCW format-0 is assumed. CCW1=NO is the default.
The following macro format is still supported.
- name
- A 3-character symbolic general tape name must be specified as the first
parameter.
- level
- A symbolic data level (D0-DF) must be specified as the second
parameter.
Entry Requirements
- R9 must contain the address of the entry control block (ECB) being
processed.
- The general tape specified by tape name must be open when this
macro is issued.
- The first 4 bytes of the file address reference word (FARW) of the data
level specified by level must contain the address of the channel
program. The channel program must only refer to addresses above
X'1000'.
- The CCWs you provide must be data chained to ensure a single block
transfer.
Return Conditions
- Control is returned to the next sequential instruction (NSI).
- The contents of R14 and R15 are unknown. The contents of all other
registers are preserved across this macro call.
- The status of the data transfer operation is unknown.
Programming Considerations
Examples
None.