IBM 3708 Description page 319

automatic polling. (1) A hardware feature of a
telecommunications unit that processes a polling list,
polling the terminals in order and handling negative
responses to polling without interrupting the central
processing unit. At the end of the list, polling is
automatically begun again at the beginning of the list.
Synonymous with autopoll. (2) See also polling.
automatic skip. After entry of a character into the last
character position of an unprotected display field,
automatic repositioning of the cursor from a protected
and numeric field to the first character position of the
next unprotected display field.
autopoll. Same as automatic polling.
auto-skip. Same as automatic skip.
base color. The capability to display or print all
characters in a field, in one of four colors, on a color
terminal by using combinations of the field protection
and the field intensify bits of the field attribute.
Binary Synchronous Communications (BSq. Data
transmission in which character synchronism is
controlled by timing signals generated at the sending
and receiving stations.
blink. An extended highlighting attribute value (for
emphasis) of a field or character.
block matrix. The total array of dots that can be used
to describe a graphic character for a 3270 display or
printer.
bracket. In VT AM, an exchange of data between an
application program and a logical unit which
accomplishes some task.
break. (1) To interrupt the sending end and take
control of the circuit at the receiving end. (2) A
separation of continuous paper forms, usually atthe
perforation.
buffer address. The address of a location in the buffer
at which one character can be stored.
character attribute. The properties of a character with
respect to its color, highlighting, and character set. See
also extended field attribute.
character buffer. The read/write storage used by a
partition for storing character or graphic data for
display or printing on a terminal.
character position. A location on the screen at which
one character can be displayed; also, an addressed
location in the buffer at which one character can be
stored.
character set. (1) A defined collection of characters in
a loadable or nonloadable set selected by means of a
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IBM 3708 Description
local character set identifier. (2) An attribute type in
the extended field and character attributes. (3) An
attribute passed between session partners in the Start
Field Extended, Modify Field, and Set Attribute orders.
clear indicator. In VTAM, a SESSIONC indicator sent
by one node to another that prevents the exchange of
messages and responses.
cluster control unit. (1) A device that can control the
input/output operations of more than one device. A
remote cluster control unit can be attached to a host
CPU only via a communications controller. A cluster
control unit may be controlled by a program stored and
executed in the unit, or it may be controlled entirely by
hardware. (2) See also communications controller.
command. An instruction that directs a control unit or
device to perform an operation or a set of operations.
communications controUer. (1) A type of
communication control unit whose operations are
controlled by a program stored and executed in the unit.
Examples are the IBM 3704 and 3705 Communications
Controllers. (2) See also cluster control unit.
configuration. (1) (TC97) The arrangement of a
computer system or network as defined by the nature,
number, and the chief characteristics of its functional
units. More specifically, the term configuration may
refer to a hardware configuration or a software
configuration. (2) The devices and programs that make
up a system, subsystem, or network.
control character. A character used in conjunction with
a Write command to specify that a control unit is to
perform a particular operation.
control codes. The hexadecimal values hex 00 through
hex 3F, and hex FF in the 3270 data stream.
control terminal. For the 3708, a display attached to a
3708 that enables an operator to communicate with the
3708 in order to control and monitor the 3708 and to
define the 3708 configuration.
control terminal mode. For an ASCII device attached
to a 3708, a mode of operation in which the device
functions as the control terminal for the 3708.
copy control character (Ccq. A character used in
conjunction with the Copy command to specify the type
of data to be copied.
copy operation. An operation that copies the contents
of the buffer from one display station or printer to
another display station or printer attached to the same
control unit.
cursor. A unique symbol that identifies a character
position in a screen display, usually the character