Display Unit; Crt Monitor; Power Supply - Texas Instruments 990 Installation And Operation Manual

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___ 1.2.3 DISPLAY UNIT. The display unit houses a 30S-millimetre (12-inch) cathode-ray tube (CRT)
monitor, power supply, control logic, audible alarm logic, and two controls to allow the operator to
adjust the brightness of the display and the volume of the audible alarm.
1.2.3.1 CRT Monitor. The CRT monitor is a 30S-millimetre (l2-inch) monitor with a selectable
capacity of 12 or 24 lines of information containing 80 characters each. The monitor produces
alphanumeric and graphic display characters using the television raster scan technique. Table 1-1
lists the principle display characteristics.
Functionally, the display is characterized by the following features:
• Alphabetic, numeric, and special
(+, -,
*, etc.) character set
• Katakana character set (Japanese Katakana model only)
• Graphic character set (1920-character display)
• 960- or 1 920-character formats
• Software-selectable cursor blinking
• Gothic font upper- and lower-case characters
• Dual intensity display (not on Japanese Katakana model).
1.2.3.2 Power Supply. The power supply in the display unit consists of a power transformer
mounted on the display unit base and regulators on the logic board mounted at the rear of the
display unit.
Table 1-1. VDT Display Characteristics
960 Characters
1920 Characters
Description 50Hz 60Hz 50 Hz 60 Hz
Character Matrix - Columns
5 5 5 5
- Rows 7
7 7
7
Character Block - Columns
7 7
7 7
-Rows
16
16
10 10
Frame (refresh) Rate
50 60 50 60
Lines of Characters 12 12 24 24
Character Rate (Dot rate divided
by dots per character in MHz.
1.57 1.57 1.57 1.57
Characters per row
80 80 80 80
Video Display Horizontal Size
Millimetres - tolerance ±6.35 215.90 215.90 215.90 215.90
(Inches - tolerance ±0.25)
(8.50) (8.50) (8.50)
(8.50)
Video Display Vertical Size
Millimetres - tolerance ±6.35 139.70
139.70 139.70 139.70
(Inches - tolerance ±0.25) (5.50) (5.50) (5.50)
(5.50)
1-5
Digital Systems Division
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