tion 59468 by a
POKE
59468,14. When
in
effect. ail the characters shown on the
keyboard, upper (with shift) and lower-case letters, numbers and some symbols
are available. The CBM standard character
is
only represented if it differs from the
standard graphie keyboard character. Otherwise, if the column
is
blank,
Vou
may
assume
that
the graphie and
typewriter
standard character
is
the same.
ALTERNATE CHARACTER
SET:
The Alternate Character Set
is
ail the characters
displayed only after poking the alternate set into effect
with
a
POKE
59468,xx.
GRAPHIC KEYBOARD: This column represents the alternate character set
of
ail
PETs
with
graphie symbols displayed upon the keyboard. This set
is
activated
only after poking value 14 into memory location 59468 by a
POKE
59468,14.
When
in
effect. upper AND lower-case letters, numbers and most of the graphie
characters are available, along
with
some special graphie characters not illus-
trated on the keyboard.
CBM KEYBOARD: This column represents the Alternate Character Set of
the CBM version of the
PET
without
graphies displayed
on
the keyboard. This set
is
activated only after poking value 12 into memory location
59468
by a
POKE
59468,12. When in effect. upper and lower-case letters, numbers, AND the
graphie characters are available. Again, the CBM character
is
represented only if
the character differs from the graphie keyboard character. If the column
is
blank,
vou may assume
that
the graphie and
typewriter
alternate character
is
the same.
PET
ASCII: As vou recall fram the discussion of the CHR$ function
in
Chapter
5,
ASCII stands for the "American Standard Code for Information Interchange."
Commodore developed its
own
ASCII code for the
PET
(and
CBM) computer
to
include its unique graphie characters.
We
will
cali this special ASCII code
PET
ASCII. Two
PET
functions, ASC() and CHR$() use the
PET
ASCII decimal numbers
to
reference its characters. The
PET
ASCII code column enables vou to find a
character's
PET
ASCII number quickly by finding the desired character and look-
ing acrass the chart for its
PET
ASCII number.
Although
both the
PET
ASCII
decimal
(DEC)
number from 0
to
255, and the hexadecimal
(HEX)
number from 00
to
FF
are given, when using the ASC( ) or CHR$( ) functions, use only the decimal
ASCII number. The last portion of the chart. the reverse characters, do not have
PET
ASCII numbers, and thus are arranged by their
PEEK/POKE
numbers,
as
ex-
plained in the next section.
PEEK/POKE:
The
PEEK/POKE
code
is
the number
that
must
be
used when either
POKEing a character to the screen, or when
PEEKING
into memory to
see
what
character
is
contained in a specified memory location; the number returned
will
be
the
PEEK/POKE
number representing
that
character. Notice
that
in most cases
the
PEEK/POKE
number
is
not the same
as
the decimal ASCII number. This code
number CANNOT
be
used
with
ASCII functions, only
with
PEEK
and
POKE.
The
PEEK/POKE
code numbers do not appear
in
strict
ascending sequence until the
reverse characters portion of the chart.
At
this point. the chart
is
arranged in
ascending
PEEK/POKE
order because the reverse
PET
characters lack
PET
ASCII
348
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