Brightness Control; Contrast Control; The Display Image - IBM 3270 Operator's Manual

8
Operating the 3270
Brightness Control
Contrast Control
The Display I mage
You can adjust the brightness of the characters displayed on the
screen by turning the outer control knob of the switch labeled
OF F-PUSH to the left or to the right. Turning it to the right
makes the display image brighter; to the left, dimmer. There is
no correct setting for the brightness of the image. Experiment
with this control until you find the setting that is most
convenient and comfortable for your viewing.
The contrast control is another aid in adjusting your display for
comfortable viewing. If your organization uses two intensity
levels to display characters (explained on page 12,1 under the
heading "High I ntensity Data"), the contrast control varies the
difference between these two levels. (The contrast control is the
inner control knob on the OFF-PUSH switch.) As with the
brightness control, there is no correct setting of the contrast
control; you must experiment until you find the contrast level
that satisfies you.
If your display station does not have a keyboard or selector pen
attached, you simply apply power with the OFF-PUSH switch
and adjust the brightness/contrast controls to make the unit
ready for operation. From this point on, operation is controlled
by the program, and you may only monitor information
displayed on the screen. If you do not have a keyboard, you
should now read about the indicators on your display station (as
described starting on page 15 under the title "Common
Indicators"). If you do not have a keyboard but have a selector
pen attached to your display station, read about the indicators
on page 15, and then refer to page 101 for a description of
selector pen operation. If you have a display station with a
keyboard, continue reading this section.
Before we talk about the keyboard, there are some things you
should know about what you can expect to see on your display
screen.
As we have said before, the 3270 I nformation Display System
can be used by many different organizations, all with very
different kinds of jobs to be done. Even within one organization,
there are many different applications for 3270 display systems.
Today's computers are capable of processing many different jobs
at the same time. Therefore, it is possible that you could be
working on one job while the operator next to you is doing