Ahoy 1986 August/Ahoy_Magazine_86-08_1986_Double_L.d64/font editor.txt

Text File | 1986-01-01 | 6.8 KB | 250 lines

FONT EDITOR
by Phyrne Bacon

A "font" is a definition of how each
character is displayed on your
screen. The font editor allows you
alter the way characters are
displayed on your screen. You can
change just one character (for
instance, remove the line that
slashes a zero) or change as many
characters as you want - even all of
them.

You choose the character to edit by
key, cursor, or screen code. The font
editor displays all 256 characters of
the font.

LOADING THE FIRST FONT

When the FONT EDITOR is run, it asks
if you want to edit a "font." or a
"set." type font.

Each "font." file includes both font
sets, referred to as alphafont and
betafont. Usually the alphafont is an
uppercase font or a custom font, and
the betafont is upper/ lowercase. If
you pick "font.", you will be asked
if you want to edit the alphafont or
the betafont. To change to another
font, see LOADING A FONT below.

Each "set." file includes only one
font. If the file name ends with ".a"
it is the alphafont. If it ends with
a ".b" it is a betafont.

EDIT MODE

After the font is loaded, the
computer will change from a screen
with the built-in font to a new
screen with the loaded font. The new
screen will have a large
representation of the letter A in the
upper left hand corner in the design
frame (a small letter A appears to
the left of the design frame, and the
screen code of the letter A appears
to the right of the design frame). A
partial list of the font editor
commands is in the upper right hand
corner (press I to see the complete
list). A display of all 256
characters is in the cursor select
frame in the lower half of the
screen.

EDITING A CHARACTER

When you begin, the cursor will be in
the upper left hand corner of the
design frame. To change a pixel, move
the cursor to the pixel and press 3
to turn the pixel on, or 4 to turn
the pixel off. Use D to delete the
row the cursor is on, or E to erase
the column the cursor is on. The
design frame has wrap: if the cursor
goes off the right edge, it appears
in the left column, or if it goes off
the bottom edge it appears in the top
row, and so on.

When a pixel is changed, it will be
changed in the design frame, in
memory, and in every copy of the
character on the screen (you
instantly see the effect of each
change).

To shift a character upward use +, to
shift it down use -, to shift it left
use *, to shift it right use /. These
shifts (rolls) are nondestructive:
what goes over the top edge, appears
on the bottom row, and so on.

CHOOSING A CHARACTER

To move to the following character,
press f5. To move to the preceding
character, press f7. To select a
(nonreverse) character by pressing
its key, first press f1. To use the
cursor to select a character, first
press f3. The cursor will move to the
cursor select frame (the font
display). Move the cursor to the
desired character and press return.
(The cursor select frame has wrap.)
To select a character by screen code,
first press f2.

COPYING A CHARACTER

To copy a character, press C (for
copy). You will be asked to move the
cursor to the character to be copied,
and to press return, and then to move
the cursor to the character to be
copied to, and to press return. The
new copy will then appear in the
design frame.

REVERSE CHARACTERS

On most fonts, characters 128-255 are
the reverse characters of 0-127. For
example, reverse-A (129) has a pixel
off wherever A (1) has a pixel on,
and vice-versa. The reverse
characters are used in the blinking
cursor.

To make a reverse of a newly designed
character, press R. This copies the
reverse of the current character n
onto n+128 (onto n-128 if n>=128),
and moves the cursor to the new
reverse character.

To save time, you can change any of
the characters 0-127, and then make
reverse copies of all of them at once
by pressing f4.

Since reverse period is used in the
character design frame, if there are
no reverse characters in a font,
press f4 to make the character design
suddenly appear in the design frame.

EXITING FONT EDITOR

To exit FONT EDITOR, press Z (which
ends the program and returns you to
the usual built-in font), or the
STOP-key (which leaves you in the
custom font). To return to both the
program and font, after any exit or
error message, type RUN or, if you
used the STOP-key, enter the CON
command.

THE DISK DIRECTORY

You can exit the program at any time
by pressing Z or the STOP-key. Type
CAT, scratch or rename any file, read
any disk directory and so on, and
then return to the program by typing
RUN (or CON, if you used the
STOP-key). Stopping the program this
way does not harm the font.

LOADING A FONT

To load a "set." font press L. To
load a "font." font, press K. You
will be asked for the name (the
"set." or "font." will have been
already typed in for you). If you are
loading a "font." font, you will be
asked if you want the alphafont or
the betafont portion. Before the font
is loaded, the new font name will be
displayed.

GETTING GARBAGE ON THE SCREEN

If you press the Commodore key and
the shift key at the same time while
working on a font, you will get
garbage on the screen. This is
because the computer is using the
non-existent second custom font for
its character designs. To return to
the readable custom font, press the
Commodore key and the shift key at
the same time. These keys toggle back
and forth between the custom font and
the non-existent second custom font.

SAVING A FONT
(usual load address)

To save a font with the usual load
address, press S. You will be asked
the name ("set." will have been typed
in for you - do not type the "set.").
When asked about the load address,
press U or carriage return. The font
will be saved as a 9 block PRG-file.
If a file with that name already
exists, the program will end. (This
doesn't harm the font.)  Then, if
desired, you can then type CAT,
scratch the existing file, type RUN,
and save the font with that name; or
just type RUN, press S to save the
font with another name.

It is best to save temporary versions
of a font frequently to avoid loss of
designs due to power failures or
other difficulties.

SAVING A FONT
(with custom load address)

You only need a custom load address
if you are planning to use the font
with a BASIC program. Press Q to find
out the load address of any PRG-file.
(This can be fun.) The load address
will be given as a multiple of 256;
for example, 8*256+0.

To save a font with a custom load
address, press S (for save), enter
the filename, and press C (for custom
load address). You will be asked for
the load address as a multiple of
256. If the load address is 8*256,
enter 8. Any real load address will
be a multiple of 8*256: for example,
8*256, 16*256, 32*256 and so on. If
the load address is divisible by
16*256, the font is being used as an
alphafont; otherwise, it is being
used as a betafont.

There is more about BASIC custom
fonts in Chapter 3 of the Commodore
64 Programmer's Reference Guide.