Pin Combination Patterns; Printout Using Bottom Pin - Epson FX Series User Manual

Firing 9 pins with 8 data lines is just a shade more difficult than firing
7 or 8 pins. It takes 2 bytes to define each 9-dot pin pattern: the first
byte determines the pattern of the top 8 pins in the usual way and only
the top bit of the second byte is used. Thus any second byte of
greater fires the bottom pin of the print head; anything less does not.
Try this sample program:
20 A$=CHR$(27)+CHR$(94)+CHR$(0)+CHR$(60)+CHR$(0)
30
B$=CHR$(85)+CHR$(0)+CHR$(l70)+CHR$(128)
60 LPRINT A$;: FOR X=1 TO
80 LPRINT CHR$(27)"@"
Figure 11-6. Printout using bottom pin
Compare this with the densities in Figure 11-4 (this one is Single-
Density). Look closely at Figure
prints in every other column. If you want to see Double-Density,
change the first 0 of line 20 to a
CHR$(27)"0" line spacing is ideal: it sets the line spacing to 9/72-inch
(9-dot).

Pin Combination Patterns

The next phase in printing graphics is to arrange pin firing
sequences into meaningful designs. Figure 11-7 shows how you might
design a dot pattern on graph paper.
In Figure
11-7,
each row of dots. At the bottom of each column we show the sum of
those labels. These sums are the numbers you send to print this pat-
tern.
Once you've calculated the numbers for a pin pattern, you can store
them in DATA statements. You separate items in a DATA statement
with commas. A program reads these items from the DATA statement
into variables with a READ statement.
Now begin a new program with a READ statement and the values
for the pattern of Figure
the program yet.
154
11-6;
1.
we show on the side of the figure the pin labels for
Enter the following lines, but don't RUN
11-7.
30:
LPRINT B$;: NEXT X
you'll see that the bottom pin
For fans of 9-Pin Graphics, the
or
128