Texas Instruments 880 - Vertical Raster Graphics; Raster Graphics

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This chapter describes how the Model 880 prints
graphics data. Graphics data received from the
host computer can be in either horizontal format
(x-plot) or vertical format (y-plot).
CAUTION
Exercise caution when printing
graphics. Continuous printing of
any dot row must not exceed a
printing duty cycle of 50% over a
period
of 6 minutes. Excessive
printhead heating and accelerated
printhead wear may result if this
duty cycle is exceeded.
6.1 VERTICAL RASTER GRAPHICS
The vertical raster graphics format makes a map
of the data received from the host to the printed
dots.
The printer accepts either 7-bit or 8-bit data
as
determined by the configuration code. When
code
39, 3A, or3B is activated (ON), 8 data bits
are received and are decoded
to a map onto the
paper
as shown in Table 6-1.
Section 6
Raster Graphics
Table 6-1. Vertical Raster Graphics Eight-
Bit Data-to-Dot Map
Character
Bit
MSB8
7
6
5
4
3
2
LSB 1
Wire
Number
1
2
3
4
5
6
7
8
Paper
Dot
top
bottom
When configuration code 39, 3A, or 3B is not acti-
vated, 7 data bits
are received and decoded to
map onto the paper as shown in Table 6-2.
Table 6-2. Vertical Raster Graphics Seven-
Bit Data-to-Dot Map
Character
Bit
MSB7
6
5
4
3
2
LSB 1
Wire
Number
1
2
3
4
5
6
7
Paper
Dot
top
bottom
6-1