Table of Contents
Advertisement
screen by placing the point of the pen on the desired data
field and pushing the barrel of the pen toward the screen.
Removing the tip from the screen turns the switch off
automatically.
6.1.1.4 Audible Alarm Volume (Optional Feature)
The loudness of the audible tone can be adjusted by the
display station operator by turning the audible alarm
volume control. The front cover must be lowered for access
to the control. On Model 1 display stations, the control
protrudes downward from the audible alarm box on the
right side of the base chassis. On Model 2 display stations
the control protrudes frontward from the audible alarm
box on the left side of the upper chassis.
6. 1.1.5 Keyboard Audible Response
A knob at the rear of the keyboard bottom plate adjusts
the volume of the keyboard audible response device.
Volume can be adjusted from off (no click when a key is
depressed) to maximum loudness by rotating the knob.
6.1.2 Internal Controls
6.1.2.1 INTEN CRT
This momentary-contact switch is located on the display
station analog card. The switch overrides intensity and
blanking pulses generated by control logic and causes a
complete raster of scan lines to be displayed when pressed.
6. 1.2.2 Focus
This control is a screwdriver-adjustable potentiometer
located on the HV power supply. Turning the control varies
the sharpness of the dots that form the characters on the
screen.
6.1.2.3 WIDTH
The WIDTH control is a screwdriver-adjustable poten-
tiometer located on the analog card. Turning this control
varies the horizontal dot-to-dot spacing, which alters the
total width of the displayed image.
6.1.2.4 CHAR HEIGHT
This control is a screwdriver-adjustable potentiometer
located on the analog card. Turning the control varies
vertical dot-toodot spacing of the displayed image. On the
Model 1 display station, it determines the overall height of
the displayed image.
6.1.2.5 ROW SPACING (Model 2 Display Stations Only)
This control is a screwdriver-adjustable potentiometer
located on the analog card. Turning the control varies
6-2
spacing between character rows and, thus, determines the
overall height of the displayed image. The ROW SPACING
control is not used in Model 1 display stations.
6.1.2.6 TOP MARGIN
This control is a screwdriver-adjustable potentiometer
located on the analog card. The control sets the top
reference line on the CRT, from which all other vertical
image adjustments are made. Once the control is set, the
reference line remains stationary during other vertical
character and image adjustments.
6.1.2.7 Image Tilt
The deflection yoke, mounted on the CRT neck, is used to
tilt the entire displayed image. Rotating the yoke adjusts
the image for squareness with the edges of the CRT bezel.
6.1.2.8 Magnetic Centering Rings
The magnetic centering rings are mounted on the CRT
neck, directly behind the deflection yoke. The centering
rings are rotated to position the displayed image about the
geometric center of the CRT.
6.1.29 -12V Supply
This control is a screwdriver-adjustable potentiometer
located on the -12V regulator card. Turning the control sets
the voltage output of the -12V power supply.
6.2 INDICATORS
Display indicators, like controls, are divided into two
categories: external and internal. External indicators are
those that can be seen without removing any machine
covers. To observe internal indicators, covers must be
removed.
Internal
indicators are accessible only to
maintenance personnel.
6.2.1 External Indicators (Diagram 6-1)
The three external indicators on 3277 Display Stations are
displayed as small boxes (blips) generated by analog
circuitry. They are displayed at the right edge of the CRT.
Each indicator has its function identified by a label on the
CRT bezel, adjacent to the indicator. The brightness of the
indicators is controlled by the Brightness control.
6.2.1.1 SYSTEM A VAILABLE Indicator
This indicator is displayed at character row 4 on Model 1
display stations and at character row lOon Model 2 display
stations. In remote system configurations, the indicator
signifies that the carrier is on and that the transmission
control unit (TCU) is online when lighted. In local system
Advertisement
Table of Contents
