Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

216 Chapter8
Intrinsics Reference
FDEVICECONTROL
EOR characters (AEOR) control directive
(FDEVICECONTROL 66) interact closely. A call to set
a single AEOR sets the specified characteras the AEOR
character, and all other AEOR characters are cleared. A
call to set multiple AEORs sets all of the characters
specified in the array, and it clears the single AEOR.
This call is not supported for use with VT.
41 Define subsystem break character.
This directive specifies the subsystem break character.
The high order byte of buffer (value*256) contains the
new subsystem break character. The default subsystem
break character is
[CTRL]Y.
If this request is issued for a terminal connected via
PAD, the host software recognizes the new subsystem
break character, but the terminal user must type a
[Return] following the subsystem break to signal the
PAD to transmit the data.
If issued against a terminal connected via VT, this call
will return a CCE condition code but no device control
action will take place.
51 Set typeahead mode.
This directive enables and disables typeahead mode. A
buffer value of 0 disables typeahead mode. A buffer
value of 1 enables typeahead mode. Typeahead mode is
disabled by default.
When a terminal is in typeahead mode, up to
224 characters may be entered before a read is posted.
The device driver stores the typeahead data in a
typeahead buffer until it receives a read. The terminal
operator may enter data in advance of the actual
posting of a read. When a terminal is not in typeahead
mode, the terminal operator may enter data only when
a read has been posted to the terminal.
If issued against a terminal connected via PAD or DTC
Telnet, this call will return a CCE condition code, but
the device control action will not occur. This directive is
not supported for VT connections to MPE V remote
devices or PCs without appropriate NS software.
Additionally, HP-UX (VT3K) supports single echo
typeahead only.
Refer to Chapter 6, “Typeahead Mode,” for more
information on using typeahead mode.