General
Application area: | Data terminal communication; see "Data terminal communication" |
Macro type: | Type O; see "O-type macros" |
This macro description applies to TIAM V13.2A.
Macro description
The TCHNG macro enables characteristics of the logical terminal to be modified by the user program.
The modifications made by the TCHNG macro remain effective until termination of the user program or until a further TCHNG macro is issued; they are valid only for this program's I/O operations for the terminal with the RDATA, WROUT and WRTRD macros.
Macro format and description of operands
TCHNG |
{ EDOPT=DYN / EDOPT=STAT{,MODE=LINE ,OHCOPY={N / Y} ,OHOM={N / Y} / ,OINFO={N / Y},ONOPOSN={N / Y} / ,OBELL={N / Y},IGETBS={N / Y} / ,ILCASE={N / Y},IGETFC= {N / Y} / ,IGETIC={N / Y},ICFD={N / Y} / ,MODE=FORM ,IGETBS={N / Y},ILCASE= {Y / N} } } ,OFLOW=SYS / USER ,SUB=OUT / OUTIN ,INFOLIN=NO / YES ,CLEAR=YES / NO |
The operands are described below in alphabetical order.
CLEAR=
Determines whether the screen is to be cleared when the output mode changes.
YES
Default setting: When the output mode changes, e.g.
from LINE to FORM
from FORM to LINE, PHYS, COMP
from PHYS to LINE, FORM, COMP
from COMP to FORM
the screen is to be cleared. If the change of mode does not occur after an input, the system waits t seconds before clearing the screen to allow users to read their last output (see the command MODIFY-TERMINAL-OPTIONS OVERFLOW-CONTROL=...).
NO
The screen is not cleared when the output mode changes. The following message is output without a waiting period.
Note
The user program must ensure that the screen contents do not affect any function of the new mode, e.g. by premodified fields.
EDOPT=
Specifies which edit options values are to be evaluated.
DYN
Default setting: edit options values specified in any subsequent RDATA,WROUT and WRTRD macro calls are to be evaluated (default values set by the system).
STAT
The edit options values specified in the TCHNG macro for MODE, OBELL, OHCOPY, OHOM, OINFO, ONOPOSN, IGETBS, ILCASE, IGETFC, IGETIC and ICFD are to be evaluated in any subsequent RDATA, WROUT and WRTRD macro calls. These specifications remain valid until modified by a further TCHNG macro or until end of program. However, they have no influence on system inputs and outputs.
EDOPT=STAT is ignored if VTSUCB is used.
INFOLIN=
Determines how incoming informative messages are to be displayed at data terminals.
NO
Default setting: Incoming informative messages are to be displayed like normal linemode messages at data terminals without a system line.
YES
At data terminals whose hardware does not provide a system line, incoming informative messages are to be displayed in the last line on the screen when a formatted or physical message is currently displayed on the screen (see the WROUT macro).
OFLOW=
Specifies the type of overflow check.
SYS
Default setting: In the event of long user program outputs, the system is to perform an overflow check to prevent information overflow at the terminal. The type of system overflow check is specified by the terminal user via the MODIFY-TERMINAL-OPTIONS command (see the “Commands” manual [19 (Related publications)], for default values and effect).
USER
The system is not to take any precautions to prevent information overflow in the event of long user program outputs. An overflow check can thus be performed individually by the user program.
Note
Operating system messages are still subject to the overflow check preset by the system or specified via the MODIFY-TERMINAL-OPTIONS command.
SUB=
Determines when the defined substitution character is to replace characters.
OUT
Default setting: The defined substitution character is to replace illegal characters for line mode outputs.
OUTIN
The defined substitution character is to
replace illegal characters for line mode outputs
transfer the logical control character SUB to the user program for line mode inputs (see the VTCSET macro).
MODE=OHCOPY=OHOM=OBELL=ONOPOSN=OINFO=IGETBS=ILCASE=IGETFC=IGETIC=ICFD=
For the meaning of these operands, see the WRTRD or WROUT macro.
Return information and error flags
R15:
+---------------+ | | | | | | | | | | | |a|a| +---------------+
A return code relating to the execution of the TCHNG macro is transferred in the rightmost byte of register R15.
X'aa' | Meaning |
X'00' | Normal termination. |
X'04' | Unrecoverable error. |
X'08' | Operand error. |
X'0C' | The caller is not in timesharing mode. |
X'10' | Operand error. |
X'14' | Invalid edit option. |