Epson LX-90 User Manual - Apple IIc 8699 PIC for LX-90 - Page 47

The “Z” Command, Multiple-Line Exercise, PRINT CHR$9;Z, PRINT CHR$27;K;CHR$lgfl;CHR$0

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The "Z" Command Some software (including ProDOS BASIC) automatically inserts the control codes for a carriage return and a line feed after every 80 - 130 characters. This insertion is usually no problem with text, but it can spoil your graphics. In the graphics mode it may insert the control codes in the middle of a line. You can usually prevent these unwanted control codes in ProDOS BASIC with a "Z" command. The format is shown below: PRINT CHR$(9);"Z" Put this command in one of the first lines of all your graphics programs. It is easier to put it in all of your programs than to examine each one to see whether or not such a statement is necessary. Multiple-Line Exercise Now that you've entered and run a simple graphics program, you can go on to an exercise that shows you how the LX-90 combines several lines of graphics for a figure taller than eight dots. Start with a line for 100 columns of single-density graphics and lines to print two pin patterns. Notice that since there are two pin patterns in the loop, it is only executed 50 times. NEW 5 PRINT CHR$(d);"PR#l" 18 PRINT CHR$(q);"Z" 40 PRINT CHR$(27);"K";CHR$(lgfl);CHR$(0); 50 FOR X=1 TO 50: PRINT CHR$(85);CHR$(42); 60 NEXT X: PRINT 100 PRINT CHR$(27);"@" 300 PRINT CHR$(4);"PR#p" If you run the program now, you'll see how one line of the pattern looks: 45

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The “Z” Command
Some software (including ProDOS BASIC) automatically inserts
the control codes for a carriage return and a line feed after every
80 - 130 characters. This insertion is usually no problem with text, but
it can spoil your graphics. In the graphics mode it may insert the
control codes in the middle of a line.
You can usually prevent these unwanted control codes in ProDOS
BASIC with a “Z” command. The format is shown below:
PRINT CHR$(9);"Z"
Put this command in one of the first lines of all your graphics pro-
grams. It is easier to put it in all of your programs than to examine
each one to see whether or not such a statement is necessary.
Multiple-Line Exercise
Now that you’ve entered and run a simple graphics program, you
can go on to an exercise that shows you how the LX-90 combines
several lines of graphics for a figure taller than eight dots.
Start with a line for 100 columns of single-density graphics and lines
to print two pin patterns. Notice that since there are two pin patterns
in the loop, it is only executed
50
times.
NEW
5 PRINT CHR$(d);"PR#l"
18 PRINT CHR$(q);"Z"
40
PRINT CHR$(27);"K";CHR$(lgfl);CHR$(0);
50 FOR X=1 TO 50: PRINT CHR$(85);CHR$(42);
60
NEXT X: PRINT
100 PRINT CHR$(27);"@"
300 PRINT CHR$(4);"PR#p"
If you run the program now, you’ll see how one line of the pattern
looks:
45