IBM 5291 1 Operator's Manual page 71

host system: The controlling or highest level system in
a data communications configuration.
image: The characters or attributes displayed on a
display screen.
input field: An area on the display in which an operator
enters data. Input fields are blank on the display and
can be preceded by a prompt.
keyboard buzzer: A short buzzing sound, controlled by
the system, used to remind or warn the operator of a
certain condition.
·mandatory enter field: A format control used to
specify that at least one character must be entered in
the field.
mandatory fill field: A format control used to specify
that if one character is entered in the field, the entire
field must be filled.
null: A blank that is displayed as the result of hex
'00' occupying character positions in the buffer.
numeric only: A format control used to specify that
only the numeric characters, comma, hyphen, period,
plus, and blank can be entered in the field.
power cord: A cord that plugs into a wall outlet
supplying electrical power.
printer: A device that provides printed output.
program: A computer program written to perform a
specific job; for example, order entry or payroll. The
program is stored in the system and can be accessed by
the display station using the Cmd key procedure.
right-adjust field: Pertains to the placement of data in
a field, or the shifting of the contents of a field, so that
the last significant byte at the end of the data is placed
in the rightmost position of the field.
self-check field: A field (such as an account number)
that consists of a base number and a self-check digit.
For example: An operator enters data and a self-check
digit, which is compared to the self-check digit
computed by the system. If the operator made a
mistake when entering the data in the self-check field,
an error message is displayed.
G-2
signed numeric field: A format control used to specify
that the units position of the field is reserved for the
sign (usually, blank for positive and minus for negative).
system: The main computer and the programming
necessary to execute customer jobs. The system can
have numerous display stations or printers attached.
system cable: A cable that carries commands and data
between the system and the display stations or printers.
system console: An I/O device (such as a display
station) designed to actuate certain system functions,
and control and monitor system operation, in addition to
functioning as an I/O device.
system operator: A person who uses a display station
that is designated as the system console, to activate
certain system functions, and control and monitor
system operation.
typematic keys: Keyboard keys that repeat their
function when pressed and held down.
unformatted display: See free key mode.
unit: One of the three f!lajor assemblies that make up
the 5291 (display unit, lower unit, and keyboard unit).