•
6.2.2
Horizontal
Raster
Data
Format/
Double-Density
Plot
Mode
In double-density plot mode (Figure 6-2), data
lines containing the
ENQ
(>05) control character
provide the even dot location pattern, and data
lines containing the
EOT
(>04)
control character
provide the odd
dot
location pattern
of
the hori-
zontal raster graphic. To print a double-density
plot
for
any given line
of
data, a line
of
odd
dot
location pattern must be entered before a line
of
even dot location pattern. Both
dot
patterns are
then merged
to
create a double-density
row
of
dots printed at half the speed
of
the single density
plot.
Either
of
two
line termination characters cause the
Model
880
to
start printing.
Each
line termination
character that follows a row
of
data initiates the
DATA
INPUT (HEX):
7E
60
74
04
OA
4A
4D 7C
05
OA
7E
= 0
1
11
1 1 1 1
01
60 = 0
4A
= 0
1
10
0
1
0
1
01
4D
0
PRINTED OUTPUT:
LEFT
MARGIN
111
0
11
0
0
1st
BYTE LSB 2nd BYTE LSB
II'
Ji'
1 2 3
4
5
6 1
2 3 4
• •
* #
•
#
* # •
# •
# *
•
•
• * • *
• • •
• • • • • • • • • •
• •
•
•
• •
* =
EVEN
DOT LOCATION
# = ODD
DOT
LOCATION
printing
of
the partial plot data. The line feed char-
acter,
LF
(>OA), causes the line
to
print and the
paper
to
move up nine dots. The form feed char-
acter,
FF
(>OC), causes the line
to
print and the
paper
to
move
to
the top
of
the next form. The
carriage return,
CR
(>00),
causes no printing or
paper motion but allows the
row
of
data to be
changed by the next data line received.
In
this plot mode, bytes
that
are outside the right
margin are discarded.
When more than one odd
dot
pattern
is
received,
data
is
saved in the same
row
until terminated, or
an
even pattern
is
entered.
Figure 6-2 shows a double-density plot
of
horizon-
tal raster data.
0 0 0
01
74 =
0
111
1
0
1 0
01
1
1
0
11
7C
0
111
1 1 1
0
01
3rd BYTE LSB
II'
5
6
1 2 3 4
5
6
• • • •
# •
•
•
• *
#
* • * •
* #
• • • •
• • • • • • • • • • •
• •
2222627-29
Figure
6-2.
Horizontal
Graphics -
Double
Density
6-5
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