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Downloadable and Custom Commands
Descenders
Earlier in this chapter we mentioned the descender informa-
tion. When we left it as a zero you probably thought this was easy.
Well, it is! We only have two choices for descender data; it's either
a zero or a one. When it's a zero, nothing happens. When it is a
one, all the dots that make up our character are shifted down two
rows. Why do we want to perform this magic? If you look at the
lowercase g in magic, you can see that the tail of the g drops down
below the bottom of other characters. This is a descender. Let's
take our copyright symbol example and define the
@
symbol as
we did before and make the" &" symbol our copyright symbol with
a descender (shifted down two rows).
;0 REM Define the Escape character
20 ESCS=CHRS (27)
~4
REM cOCy characters to RAM
2~
LPRINT ESCS:CHRS(42):CHRt(O):
30 REM Define copyrIght symbol in olace of
@
40 LPRINT ESCS:CHRS(42':CHRS(1):CHR$(64):CHRt(O);CHRS(ZS):CHRS(34);CHRS(73';
CHR.(20)ICHR'(6~l:CHR'(20)ICHR'(65):CHR'(34):CHRt(20);
44 REM DefIne cooyright symbol in alace of
~
45 LPRINT ESCS:CHRt(42);CHR'll':CHR'(3B):CHRS(l':CHR'(2B';CHR'(341;CHRS(731:
CHR'(20)ICHR'(6~)ICHR'(20):CHR'(6~):CHR.(34)ICHR'(20)1
SO REM Select downloadable characters
60 lPRINT ESCIICHRt(36)ICHRS(1):
70 REM Print our new symbols
90 LPRINT
·'~'&@&@&@&'&@&I&·
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Figure 8-6. Program listing to print:
":'.:.
':\.::':=:';~·@~"f·;<:;€,:;:.f:,i::
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One more instruction you'll need before we leave
downloadable characters: How to turn them off.
CH R$(27) CH R$(36) CH R$(O)
Turning downloadable characters on or off during a line will
affect all characters on that line. In other words, if you turn on
downloadable characters anywhere in a line, all of the characters
on that line will be treated as downloadable characters.
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