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

200 Chapter8
Intrinsics Reference
FCONTROL(41)
FCONTROL(41)
Parameters
controlcode 41 — Enables transparent editing.
param 16-bit unsigned integer by reference
(required)
Passes a value to be used as a subsystem break
character in bits (0:8) and a value to be used as a read
terminator in bits (8:8).
Returns the values previously assigned for use as
subsystem break and read terminator characters.
Notes An FCONTROL call with a controlcode value of 41
will place a terminal in transparent editing mode. Also
called unedited mode, this facility allows most special
characters to be read and treated as data. Unlike
binary mode, however, which allows no special
character processing to occur, transparent mode allows
a small subset of special characters to retain their
meaning. These characters are listed in Table 8-6.
In addition to the characters shown in Table 8-6, two
other characters have a special meaning to the system
during transparent mode processing. The characters to
be assigned these meanings are specified in the call
through the value entered in param.
Bits (0:8) of param are used to specify the character
that will replace the subsystem break character. Any
character not otherwise defined as a special character
in transparent mode, including the normal subsystem
break character (
[CTRL]Y), can be used. If this value is
set to 0, subsystem break is disabled.
Bits (8:8) specify the character that will replace the line
termination character (EOR) for the transparent mode
read. Any character not otherwise defined as a special
character in transparent mode may be used.
While binary mode reads terminate only on byte count
or a read timeout, transparent mode reads can be
terminated in any of the following ways: