TM 5-6675-316-14
(h) The address locations in the display memory describe the X- and Y-
coordinates relating to the monitor screen. The characters appearing on the first
line of the screen would be stored in the first 64 locations of the display memory
as an 8-bit code.
(i) The crystal oscillator provides the main timing control of the display
system, each cycle of the oscillator representing one dot on the screen. The X-dot
counter divides the output of the oscillator by the number of pulses designated for
the width of the character matrix block plus one dot on either side of the matrix
for spacing.
(j) The X-field counter counts the number of character matrix blocks on a
line. As each character is completed, the X-dot counter increments the X-field
counter by one. When the character count matches the selected count, the X-field
counter generates a horizontal drive signal.
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