Bit Image Programming Format - Printronix P7000 H-Series Programmer's Reference Manual

Appendix C
Graphics
Double Density Mode: ESC L
Double density mode prints up to twice the number of dots per inch
horizontally in the same space used for single density. The vertical dot density
remains the same as in single density mode. Double horizontal density
requires twice the number of input data bytes to print the same length line as
single density. Printing double density reduces the printing speed by half.
Double Speed-Double Density Mode: ESC Y
When the double density-double speed control code is received, data bytes
print at double the current horizontal dot density, but adjacent dots are not
printed. Since double density graphics are printed at half speed, double
speed-double density graphics are printed at the same speed as single
density graphics. This mode is often used to position a simulated print head
precisely by sending blank dot columns.
Quadruple Density Mode: ESC Z
When printing quadruple density graphics, the printer combines adjacent
quadruple density bit image bytes. The compounded data is then printed in
double density mode.

Bit Image Programming Format

The bit image command format is:
The syntax of the bit image expression must be correct.
The number of data bytes and the n1 , n2 definition must be equal.
Any characters following n1 and n2 are interpreted and plotted as data until
the n1 , n2 definition is satisfied.
If n1 = n2 = 0, then control codes K, L, Y, or Z are ignored.
The maximum number of data bytes that can be included in the DATA portion
of the program statement (when using 132 column paper) varies according to
the dot density:
122
ESC CC ( n1 ) ( n2 ) DATA
Where:
ESC = the serial matrix escape sequence
CC = K, L, Y or Z to select dot density
(K = single, L=double, Y=double density, double speed,
Z=quadruple density)
n1 = (Number of DATA bytes) - 256( n2 )
(remainder of division of number of DATA bytes by 256,
sometimes referred to as MOD 256)
n2 = (Number of DATA bytes) / 256 (quotient of division)
DATA = the dot pattern bytes
At 60 dpi, single density = 792 bytes
double density = 1584 bytes
quadruple density = 3168 bytes