Major Assemblies; Display Monitor - Control Data Corporation CDC CC63X Hardware Maintenance Manual

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An internal ROM (figure 4-1) contains the resident CYBER mode,
resident diagnostics, and controlware loaders. The diagnostics
consist of self tests which are performed each time the terminal
is activated for use. (POWER on or RESET.)
The nonvolatile memory (NVM) is a RAM device which stores
keyboard-entered operating parameters for a selected operation.
A battery maintains the stored data when terminal power is
removed. If terminal power is ever turned off and the battery
removed, default parameters are forced into the nonvolatile
memory (default parameters are described in the manuals listed in
the preface).
The pluggable memory module (ROM pack) is optional and can be
used in a number of special operations. The terminal can
checksum the ROM pack contents, and load operating firmware from
the memory module.
MAJOR ASSEMBLIES
Figure 4-2 depicts the major assemblies comprising the display
terminal and the following paragraphs describe those assemblies.
DISPLAY MONITOR
The display monitor consists of a cathode-ray tube (CRT) with
yoke and a CRT monitor board. The CRT screen provides a display
of alphanumeric and graphic symbols. A green phosphor screen and
reduced-glare faceplate is used. The screen measures 380 mm (15
inches) diagonally with a 203 mm (8 inch) by 262 mm (10.3 inch)
viewable area.
The CRT monitor board contains the horizontal and vertical
deflection circuits, video circuits, and the high voltage power
supply. These circuits are responsible for generating and
deflecting the electronic beam in the CRT/yoke assembly. The
video signal unblanks (illuminates) the screen dots at the proper
times to present readable information. Vertical and horizontal
sync pulses ensure a stable trace. The sync pulses and video
signal originate on the main logic board.
Directly below the CRT are the operator controls. Refer to
Section 2 for a description of these controls.
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