Epson SQ-2550, User Manual

Page: 130 / 315

Graphics
For example, if you wish to send 1632 columns of graphics data,
nl should be 96 and n2 should be 6 because 1632 = 96 + 6
x
256.
The printer will interpret the number of bytes determined by nl
and n2 as graphics data, no matter what codes they are. This
means that you must be sure to supply enough bytes of
graphics data or the printer will stop and wait for more data
and will seem to be locked. If, on the other hand, you supply
too much graphics data, the excess will be interpreted and
printed as regular text.
A simple graphics program
This first program is just a simple example to show you how
the graphics command, column reservation numbers, and data
can be used in a BASIC program.
Type in and run the following program; be especially careful to
include both semicolons. The program produces the printout
you see below it.
10 WIDTH "LPT1:",255
20 LPRINT CHR$(27)"*"CHR$(32)CHR$
30 FOR X=1 TO 120
40 LPRINT CHR$(170);
50
NEXT X
(40)CHR$
(0) ;
Line 20 selects single-density 24-element graphics mode 32 and
also reserves 40 columns for graphics. Since 24-element
graphics requires three bytes of data for each column, line 30
begins a loop to supply 120 bytes of data. Line 40 contains the
number 170, which produces the first element pattern shown in
the section on nozzle labels, and line 50 finishes the loop.
Software and Graphics
4-15