TM 5-6675-316-14
ERASE is initiated by a command from the character generator board. It is termi -
nated by another command from the same board. This END ERASE signal is generated on
the character generator board after the fourth line has been erased.
(3) Roll control circuit. The roll control circuit causes the bottom four
lines on the monitor to be transferred to the top four lines, and the top four
lines, which have just been erased, to the bottom four lines. This is achieved by
modifying the Y-field addressing to the display memory. The roll control circuits
generate the ROLL signal and transmit it to the character generator board. This
signal initiates the address modification. The address remains modified until the
next ROLL command is received when it returns to its unmodified mode.
Note that the data has not been moved; only the sequence of displaying the informa-
tion.
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