Graphics Of Low Resolution - Oki Microline 3390 User Manual

Chapter 11: IBM - Graphics
Graphic densities
11-8

Graphics of low resolution

This relates to 8-pin modes which are supported by most graphics
programs running under DOS. With these graphics, it is first neces-
sary to choose the reproduction ratio which defines the assignment
of graphic bits to the pins of the print head and thus also the graphic
resolution for the graphics modes.
Function
Activate single
density graphics
Activate double density
graphics and half print
speed
Activate double
density graphics
Activate quadruple
density graphics
As with 24-pin graphics of high resolution, you also create a bit pat-
tern in this case as a series of dot columns. In doing so, each graphic
column is described in the 8-pin modes with one byte.
The variables n and n
1
of graphic data will follow. Remember here that, in 8-pin mode,
only one data byte is available per graphic column.
The resolution of the four graphic densities of low resolution de-
pends on the item »Aspect ratio« described later. The initiating
command sequence for graphic printing determines one of the four
possible resolutions.
Applying to the graphics modes that can be activated with ESC Y
and ESC Z is the restriction that, in the horizontal direction, no im-
mediately adjacent dots may be set. The dots, however, lie in any
case so close together that a line appears to be drawn through them.
Dec. Hex.
27 75 1B 4B
n n n
1 2 1
27 76 1B 4C
n n n
1 2 1
27 89 1B 59
n n n
1 2 1
27 90 1B 5A
n n n
1 2 1
n = total number - (n
1 2
n = total number graphic characters / 256
2
communicate to the printer how many bytes
2
ASCII
ESC K
n n n
2 1 2
ESC L
n n n
2 1 2
ESC Y
n n n
2 1 2
ESC Z
n n n
2 1 2
*256)