0.0.
0 .
0
0
0
0 0
0.0.
Figure 9-l. The letter “C” is created by printing 15 dots.
-
descenders (such as the lower case “p” shown) use the bottom
seven pins. As the printhead moves across the page (in either
direction-that’s what is meant by bi-directional printing) it prints
one column of dots at a time. Each time a dot is supposed to
print an electromagnet inside the printhead causes the appropriate
wire to strike the ribbon (making the SR- 1 O/l 5 an impact printer).
_ I
-
-
-
--
-
0.0.
: .
0
:-
0.0.
:
0
: .
00 0
0.0.
l oao :-
0
0.0.
0
-
-_
--
-
Figure 9-2. As the printhead moves across the page, each of the wires
prints one row of dots.
THE PRINT MATRIX
-
All of the standard characters that the SR-lo/15 prints are
formed from patterns of dots that are permanently stored in the
printer’s ROM (read-only Memory). This includes all of the
standard ASCII characters, the block graphics and special
characters, the international character sets, the NLQ characters
and the italic characters.
-
82 -
