Designing Characters - Epson FX-80 User Manual

LPRINT
CHR$(27)1&"CHR$(~)CHR$(65)CHR$(69);
or:
LPRINT CHR$(27)1&ICHR$(~)IAE";
selects characters A through E.
On some occasion you may wish to define only one character.
That's okay, too. Just use the same number for
C
1
and c
2 •
In fact, let's do
that now. Add:
13~
LPRINT
CHR$(27)1&ICHR$(~)IEE";
, Model I users see Appendix I
The trailing semicolon is very important. The ESC"
&"
sequence
expects more data to follow (just as Graphics Mode does). The trailing
semicolon prevents an unwanted carriage-return code from disrupting
the data.
For each character to be defined (determined by
C
1
and c
2 ),
the
printer expects 12 data numbers to follow. The first of these numbers
is called the "attribute byte." It determines some special attributes or
characteristics of the character being defined. The next 11 numbers
contain the dot patterns of the symbol being defined-nothing fancy,
just 11 standard graphics pin patterns.
Designing characters
The first step in defining a new character is to layout the dot pat-
tern. Check Appendix B to see how the ROM characters are designed.
User-defined characters share the same limitations as those found in
the ROM. Characters can be a maximum of 8 dots tall (even though
the matrix is 9 dots) and 11 dots wide. Most characters, as shown in
the Appendix, use only the top 7 pins of the print head; lower-case
characters with descenders use the bottom 7. Also note that all charac-
ters except for the underline (decimal 95) leave the last two columns
unused; this provides space between the letters when they are printed.
Figure 17-2 shows the design of a letter E in an 8 by 11 matrix.
197