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DIDS-402-2AMI3
The Display Terminal consists of the following major circuits and
components:
a.
Keyboard Assembly All
b.
Display Logic Board Al3
c.
Communications Control Board A12
d.
Timing and Discrete Board A14
e.
Delay Line Electronics A9
f.
Delay Line A15
.,g,.
Monoscope Deflection Amplifier Assembly A3
h.
Video Preamplifier Assembly A 7
i.
Video Amplifier Assembly A8
i.
Vertical and Horizontal Deflection Amplifier Assembly A2
k.
Low Voltage Power Supply A4
I.
High Voltage Power Supply A5
m.
High Voltage Network As sembly A6
n.
Monoscope VI
o.
Cathode Ray Tube V2
1-2.1 Keyboard Assembly A11
The keyboard assembly (figure 1-2) provides a means of initiating and
editing data messages, and controlling various display terminal operations.
The
74 keys are arranged in an essentially USA Standard keyboard layout and have
touch characteristics similar to a high-quality electric typewriter.
Control
keys are centralized at the right and left edge s of the keyboard to prevent their
unintentional depression during message composition.
Noise-free operation is
provided by magnetically actuated reed switches which enable current flow
through a specific branch of a self- contained diode matrix.
The code produced
by the depression of a character key is used internally to produce a corresponding
visual character on the CRT screen and externally to form a specific character
of the transmitted message.
In
addition to the standard keys used for composing
messages, the keyboard contains many special function keys.
These keys (such
as END, XMIT, ERASE MSG) are used for editing or control purposes.
1-3
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