Epson FX-80, User Manual

Page: 177 / 376

2. Translate the dots into their appropriate pin numbers, seven or
eight rows (depending on your computer system’s capability) at
a time.
3. Figure out the easiest way to send those numbers to the printer.
Once you get the hang of it, the whole process is easy. It does require
some patience, but sometimes, when regular patterns form your
designs, you can use the computer to do most of the tedious work. It
can calculate the pin patterns.
Follow the development of the programs in this chapter, then get
yourself some graph paper and a pencil and have a good time.
STRATA Program
This program prints (in Double-Density Graphics Mode) a sample
logo that will be used again in Chapter
17.
As shown in Figure
12-1,
we drew the design on graph paper, using six horizontal rows consist-
ing of 7 vertical dots to correspond to the 7-dot line spacing we will
use. Each of these rows corresponds to one pass of the print head,
making it easier to calculate the pin patterns.
Here is the DATA line for the first row. Be sure to enter the line
numbers exactly as shown. Type:
NEW
800 DATA 0,1,2,4,11,18,36,72,-16,16,
64,8,64,8,32,16,0,-7,0,0,128
The program’s handling of the data is fairly straightforward. In most
cases, the program merely reads a number and sends it to the printer.
To make this happen, add three lines:
Since
127
is the largest number that can fire seven pins, you will
place a 128 at the end of each DATA line as a “stopper” number to
signal the end of the print line. Line 610 tests for a stopper. When it
reads an N of 128, it passes control to line 650, which produces the
necessary line feed. This makes line 650 the only exit from the continu-
ous loop.
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