Changing Densities; High-Speed Double-Density - Epson FX-80 User Manual

ics. TRS-80 users should watch out for numbers 0, 10, and 12; Apple
users, for 9 and 13; and those of you with other systems may have
your own sets of surprise codes.
Does this mean that you can't use these pin patterns in your graph-
ics programs? Well ... yes, it does. At least, not via the usual CHR$
function. But you can often design around these problems or POKE
the trouble codes directly to the printer. Learning how to cope with
these problems is part of learning how to use the printer with your
computer. See Appendix H for a discussion of alternatives.
Changing Densities
There is a way to compress the density of dots used for graphics that
is comparable to changing from Pica to Compressed Mode for text.
It's just a matter of entering a different one of the several Graphics
Modes. Before you try any of them out, make these changes in your
current program:
3~
B$=CHR$(85)+CHR$(42)
4~ LPRINT A$;: FOR X=l TO 6~: LPRINT B$;: NEXT X
5~
LPRINT
n
SINGLE-DENSITY GRAPHICS ";
6~
LPRINT A$;: FOR X=l TO
6~:
LPRINT B$;: NEXT X
The printer fires pins 1,3, 5, and 7 in the first column and pins 2,4,
and 6 in the second. And it alternates that sequence for 120 columns-
120 columns in the normal density.
The program also mixes graphics and text on the same line. It does
that by using trailing semicolons to keep both kinds of output on the
same print line.
High-Speed Double-Density Graphics Mode
Now let's print the same pattern in twice the normal (Single-Density
Mode) density. Make these changes:
2~ A$=CHR$(27)+"Y"+CHR$(12~)+CHR$(~)
, Change K to Y
5~
LPRINT " HIGH-SPEED DOUBLE-DENSITY GRAPHICS ";
143