Chapter
6:
Graphics
195
This contact between characters
is
what enabled us
to
build players
made up
of
mUltiple characters. This also means that you must include
spaces in some
of
your character definitions.
If,
for example, you wanted to
display the Greek "lambda" character in a scientific formula, you might
define it like this.
Displayed Dots
Binary Decimal
00000000
0
#
01000000
64
#
01000000
64
#
00100000
32
#
00010000
16
# #
00101000
40
# #
01000100
68
00000000
0
Like Commodore,
we
left "white space" at the right and the bottom of
the lambda. This makes it line up with the other characters when displayed.
MISSING
DOTS
Some quick arithmetic will tell you
that
if there are eight dots in each
row of a character and
22
characters on each line of the screen, this accounts
for only
176
dots.
We
stated earlier that there are about 500 dots on each row
of the TV screen. What happened to the others? Some of them are lost
because the electron beam in the picture tube actually sweeps a little beyond
the edges
of
the screen. Some of them are taken up by the border
of
the
display. The main reason for the difference, however,
is
that each dot
displayed by the VIC
is
two "TV dots" wide and two "TV lines" high.
Throughout the remainder of this book,
we
will use the word
"dot"
to refer
to a dot displayed by the VIC, rather than a "TV dot."
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