IBM 2265 Manual page 11

Note:
A maximum of sixteen 2845's may be multi-dropped
on one communications channel.
_ _ _ Communications
Channel
Figure 1. Typical Connection of an IBM 2845 Display Control to a Remote Central Processor Showing Application in a
Multidrop Communications Network.
complete, the operator visually verifies the message and
then depresses the ENTER key. At the same time, the
Ikeyboard locks and the ENTER PENDING indicator on the
keyboard lights. The next time the Display Station is polled
by the central processor, the completed message is auto-
I
matically transmitted to the processor. The ENTER
PENDING indicator remains lit until the polling operation
has been successfully terminated. When the indicator turns
off, the Start of Message (SOM) symbol disappears, the
keyboard unlocks, and the operator is free to key in another
message.
Under program control at the central processor, messages
may also be sent from the central processor to the 2845
and displayed on the Display Station screen. Characters of
the message text are displayed on the screen, beginning at
the character position currently occupied by the cursor.
If the Display Control is equipped with the Line Addressing
feature, the program may designate that the first character
be displayed in the first character position of a specified
line. By the use of various commands, the program may
erase all data from the Display Station screen or may caUse·
all data stored in the display buffer to be transmitted to the
central processor.
Tlie screen may also be erased by the Display Station
operator. In addition to being able to erase the complete
screen, the operator may selectively erase all data from the
cursor to the end of that line or from the cursor to the end
of the screen. The operator may erase any character or
replace it with another simply by positioning the cursor
to the described character location and depressing the
I
SPACE/ERASE-ADVANCE bar (to erase the character) or
Introduction 11