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3.11.7 Mode C Graphics Commands
Dot addressable graphics may be printed at 60 or 120 dots/inch (dpi) horizontally by 72 or 144 dpi vertically.
ESC A must precede each line of 60 dpi data with a maximum of 480 data bytes. ESC B must precede each
line of 120 dpi data with a maximum of 960 bytes. Each line of data must be terminated by a feed command,
usually a VT e, ESC 1 or ESC 9.
Each data byte is of the form 1ABCDEF where A is the lowest and F is the highest of 6 vertical dots printed in
a single dot column. Each bit must be set to a 1 for the corresponding dot to be printed.
VT e moves a document up 5/60 inch and positions it for printing contiguous rows of graphics since 5/60 is
the same height as 6/72. The RS command is useful for filling multiple blank dot columns. For example, the
following sequence will print a diagonal line starting in the upper left corner of column 1 and slanting down to
the right:
ASCII
Hex
ESC A A B D H P ` VT e
1B 41 41 42 44 48 50 60 0B 65
ESC A RS F A B D H P ` VT e
1B 41 1E 46 41 42 44 48 50 60 0B 65
ESC A RS L A B D H P ` VT e
1B 41 1E 4C 41 42 44 48 50 60 0B 65
ESC 1 feeds a document up 1/120 inch or about one half dot height. Graphics can be printed at a vertical
density of 144 dpi by using ESC 1 but the host must interleave the data. Each line of data must contain dot
data for every other row of dots to be printed. After an ESC 1 and the next line of dot data, an ESC 9 moves
the document 9/120 inch and positions it for printing the next contiguous row of dots.
Assuming full width lines, graphics throughput is 18 seconds/inch for 60 by 72 dpi and 22 seconds/inch for
120 by 72 dpi. Speed is halved when printing 144 dpi
vertically
