QuickFont is a user font editor in BASIC for the Timex Sinclair 2068 and Sinclair ZX Spectrum.
I originally wrote this on my TS 2068 back in 1985. I typed it into an emulator from a listing made on the TS 2040 thermal printer that I kept with lots of other printouts for many years. I then started to fix a few bugs and make improvements all these years later.
--- Ryan Gray
The ZX Spectrum and compatibles had the ability for a user-defined font by
changing the system variable CHARS to point to the bytes containing the
character bit patterns. Normally, this variable points to the character bytes
in the ROM. The characters from space (32) to the copyright symbol (127) are
definable in this group. The block graphics characters are not included (their
codes are above 127). The user-defined graphics (UDG) characters are separately
definable using the methods described in the user manual.
There are 96 definable characters, each defined by 64 bits contained in 8 sequential bytes for a total of 768 bytes. The patterns are defined the same as with UDG characters. There is no reserved memory for a user font as there is for the UDGs, so you have to reserve the memory yourself. This program does this for you by moving the top of the BASIC area down by 768 bytes to place the font just below the UDGs in memory. When you are done, you could clear the program with NEW and the font will still be there at address 64600.
Once a user font is loaded it is "activated" by pointing CHARS to its
location. You actually point CHARS to the location minus 256 bytes, which is
because the ROM saves instructions and time by not subtracting 32 (the code of
the first definable character) from a character code when computing the byte
offset in the font for the character. It just multiplies the code by 8 (bytes),
and since 8*32 = 256, this means the first byte of the first character is at
offset 256, so they made the font address pointer store the actual address
less 256 bytes so that adding the offset gets you to the right place. This
seems odd, but since this opertion is done so frequently in printing, not
having to subtract 32 each time helped speed things up on old, slow hardware.
Once loaded and activated, your program listing, editing, and printing will use the font. This includes printing to the thermal printer. Printing to regular printers through an interface will not use the font as those work by sending character codes rather than bit patterns.
QuickFont reserves some memory immediately below the UDGs by using the CLEAR
statement which moves the top of the BASIC area down as defined in the system
variable RAMTOP. It then lets you edit the characters, storing them in this
area. This address is normally 64600. It lets you save and load the font to and
from tape, so they will have this as a default address stored in the saved file.
However, you can always load them into whatever location you need to by giving
the address when loading the bytes, e.g.: LOAD ""CODE address
To load a font for use, you need to reserve memory for it as well as point the
system variable CHARS to it. There is a sample font loader program in
FontLoader.tap to show you how to do it. You can load the font into a
different location if you wish by giving the LOAD ""CODE command the desired
address. Since the font is above RAMTOP, it will persist even after a NEW
command until you reset the machine or move RAMTOP above it. An exception is
when loading the font into an reserved area such as with OS-64 storing the font
in RAM in the unused screen attribute area.
There are some sample fonts included stored in .tap files. You can use the
FontLoader program to load them, or load them yourself.
The files in the distribution (QuickFont.zip) are:
-
QuickFont.tapThis is the main program. It only contains the main program. It will autorun when you load the program.
-
QuickFont_OS64.tapThis is the version made for running with Zebra System's OS-64 cartridge. It is useful if you are going to edit a font or UDGs to be used under OS-64. This is still an older version (2.2f), and needs updating. OS-64 copies the ROM font to RAM (in the display file 1 attributes area which is unused), which makes loading user fonts easier since you don't have to
POKEthe font address, but you do have to load it into that address. -
Font files (
*_font.tap)I've included several font files to get you started. Many of them were ones I made back in the 80s. They are a
CODEbytes segment, each in separate .tap files. You can mount the .tap file and then load the font into the editor. -
Font Loader Example (
FontLoader.tap)This is a small program that demonstrates how you might load a font in your own programs. The .tap file contains the sample program and a font.
-
Tilde and Vertical Bar Characters (
tildebar.tap)The Timex Sinclair 2068 issn't able to display these two characters from the Sinclair font, although the bit patters are in the ROM. Timex replaced these with the new tokens for the
FREEandSTICKfunctions. You can still edit these in the font but on the 2068, you can't use them directly. This utility copies the bytes for them into the first two UDG characters. -
QuickFont_zmb.basThis is the main source file in a Zmakebas format from which
QuickFont.tapis made. -
QuickFont.basThis is made from
QuickFont.tapto not have the comments fromQuickFont_zmb.bas.
To do some of its operations quickly, QuickFont uses a little bit of machine code to help out. This should be already stored in the line 1 REM statement and not have to be loaded on startup. If is does need to be loaded, then the program will do that from some DATA statements when it is first run.
The cartridge (.dck file) version runs with the BASIC code in ROM, so it has to load the machine code into RAM. It puts it just below the user font in memory and adjusts RAMTOP down to just below that. A future version may just always store the machine code this way, loading it from a separate CODE segment in the .tap file.
The main screen dispays the current user defined font in 4 rows with the ROM
font character underneath each for reference. There is the help for the view
mode to the left, a preview of the selected character to the right, and a
magnified view of the selected character in the middle. You can press a key to
view that character of the font. You then press Enter to go into Edit Mode
to edit the selected character.
You can change the background color for the character preview on the right side by pressing shift 5 and 8 to cycle the background color. This also works when in Edit Mode, except you don't use shift.
From View Mode, you can press Symbol Shift and A (STOP) to quit the
program. This will display the POKE commands for activating the font.
There are a few characters that are normally entered in Symbol Shift mode
(E cursor). You can select them similarly by pressing Caps shift and
Symbol Shift, after which you hear a beep and can then press the key of the
extended mode letter, except you don't have to hold down Symbol Shift. This
applies to the symbols [, ]', `, {, }, and the copyright symbol, each
under the keys y, u, d, f, g, and p, respectively. This entry system
also applies to typing in Test Mode. Pressing any other key cancels the
temporary mode. In view mode only, you can actually just press symbol shift
and the letter, except for p, to get the character since these keys have
word tokens for their regular symbol shift.
Note that the tilde ~ and vertical bar | don't appear on the TS 2068
keyboard because these were replaced with the keywords FREE and STICK, and
unfortunately, these characters can't be normally printed even though they
are there in the font. You can select them and edit them on a 2068, but you
will see FREE and STICK in displayed except for in the magnified bits
view. See the bonus program in tildebar.tap which gives you access to these
two characters by copying their bytes from ROM to the UDGs A and B.
Also, on the TS 2068, the { and } characters don't appear on the keyboard,
but as the manual describes, they do exist in extended mode on the f and g
keys. This seems to be because ON ERR and SOUND are keyword mode commands
and FREE and STICK are leter mode functions, so the extended shift of f
and g in letter mode doesn't make sense to insert a command keyword, so it can
insert the brace characters instead. The letter mode functions are entered in
extended letter mode, so it's not possible to also get the tilde and vertical
bar characters in the same mode.
The keys in view mode are:
Key Function
Enter Go into edit mode for the current character
Shift+1 Show the character byte codes
Shift+2 Cycle the application background color
Shift+3 Save the font or UDGs to tape
Shift+4 Load a font or UDGs from tape
Shift+5 or 8 Change the preview box background color
Shift+6 or 7 Change the preview box foreground color
Shift+9 Switch between editing the font and editing the UDG
characters in the A-U characters
Shift+0 Enter the test mode to type with the font
SymbolShift+q Quit the program
Shift+Symbol Enter a one-keypress extended mode to get the characters
Shift [ ] ~| \ { } and copyright by then pressing y u a s d f g or p
SymbolShift+ Shortcuts to enter the characters: [ ] ~ | \ { }
y u a s d f g
SymbolShift+e Copy the ROM font over the user font (with confirmation)
Other keys Views that character
In the view menu, you can press shift+9 to toggle editing the UDG characters in character positions A though U. The character labels below them with change to inverse video to indicate this mode. During this mode, the save and load functions will apply to the UDG chaaracters only. It will keep separate file names for the font and UDGs which is shown on the top line.
Also, during this mode, the user font characters A-U are temporarily swapped with
the UDGs A-U, so stopping the program here abnormally, will leave them swapped.
You can either just use CONT to continue the program, or try GO SUB 7300 to
swap them back if variables haven't been cleared. Otherwise, you could RUN the
program again --- it will not think they are swapped --- and press shift+0 to
swap them, press BREAK (shift+space), and then re-RUN the program.
This lets you edit the bits of the current character by pressing the space bar
and using the keys a, z, k, and l to move the cursor left, right, up,
and down, respectively. When done editing, you press enter again to save the
changes. While you are editing, an actual size preview is shown in the box on
the right of the screen.
The keys in edit mode are:
Key Function
a and z Move edit cursor up and down
k and l Move edit cursor left and right
Arrow keys Also for edit cursor movement
space or b Toggle bit on/off
5 and 8 Change preview box background color
6 and 7 Change preview box foreground color
0 Clear all bits (with confirmation)
e or >= Copy bits from the ROM character with confirmation
E Copy bits from the ROM character without confirmation
Shift+1 Cancel edits and go to view mode
Enter Save edits and go to view mode
? Show other key help:
A,Z,K,L Shifted a/z/k/l shifts bits up/down/left/right
c and p Copy and paste bits between chars
h and v Flip bits horizontally or vertically
r Rotate bits left (less than key)
t Rotate bits right (greater than key)
When you save changes to a character, the updated character will then appear in
the user font shown in the top half of the screen.
Pressing shift+9 in view mode takes you to test mode which lets you type
using the user font. It uses the paper and ink colors from the character preview
box. You can type for multiple lines as well as use the delete key to backspace.
Then press STOP (symbol shift + a) to quit and return to the view mode.
You can access the extended mode characters here with the one-key extended mode
as well.
The keys in test mode are:
Key Function
Shift+2 Toggle caps lock
Shift+0 Backspace delete
Shift+9 Enter a one-keypress block graphics character mode
Shift+Symbol Enter a one-keypress extended mode to get the characters:
Shift [ ] ~| \ { } and copyright by then pressing y u a s d f g or p
SymbolShift+a Exit test mode and return to view mode
Pressing shift+4 in view mode lets you load a font from tape previously
saved as a code block by this program or manually. It should be a code block of
768 bytes, but it doesn't have to be from the same address as it will be loaded
into the address the program is currently using for the user font.
It prompts you for the name of the file on tape, but you can just leave it blank
and just press enter to load the next code block on the tape. For running in an
emulator, you may need to mount a different tape file. To not load a file, enter
the keyword STOP as the name by pressing Symbol Shift + a then enter,
and you will return to the view mode.
If you are currently editing the UDG characters, the load applies to those instead, and it keeps a separate file name for them. In this case, 168 bytes will be loaded to address 65368 (USR "a").
Pressing shift+3 in view mode lets you save the current user font to tape.
It will prompt you for a file name to give it. You can enter nothing to cancel
saving and return to the view mode. The font will be saved to tape as a code
block of 768 bytes from the address 64600. This can be loaded later, and the
address it loads to can be changed as with loading any code block by giving the
address with the load command as LOAD "name"CODE address. See the sample font
loader program.
If you are currently editing the UDG characters, the load applies to those instead, and it keeps a separate file name for them. In this case, 168 bytes will saved from address 65368 (USR "a").
See the included sample font loader program for an example of how to reserve
memory for the font, load the font, and activate it. You might change the
location it is stored, in which case, you need to load the code to that location
as well as set the CHARS system variable to point to that location (less 256
bytes).
The example uses the typical location of 64600:
-
Reserve memory by moving
RAMTOPto at least one less than the font location:CLEAR 64600-1 -
Load the font from tape. Its best to specify the location in case it is not what you expect. Specify the length for the same reason.
LOAD ""CODE 64600,768 -
Activate the font by setting the
CHARSsystem variable. This is a two-byte variable since it specifies a memory address, and thus needs twoPOKEcommands to set. If done manually, you should do this with a multiple statement line of twoPOKEcommands, otherwise, you set one of the bytes, and the font pointer immediately changes, making the next command very hard to enter since you won't be able to read what you are typing.POKE 23606,88: POKE 23607,251This causes the
CHARSsystem variable to point to store the address88+256*251, which is 64344. This is the actual address of the font, 64600, minus 256 bytes as previously explained.
After creating a font (and saving it), when you quit the program, you can do these POKEs to activate the font still in memory. You can then give the NEW command and start programming using your new font.
You could also do these operations in your own program to have it use your font.
Just be aware that the CLEAR command with a memory address also does clear the
variables like the regular CLEAR command, so you will need to do that at the
beginning of your program before setting variables.
This was pretty much as it was in the printed listing with a few flaws and probably not the last version I made, but it will be a while before I get to resurrecting files from my old tapes.
I started to make improvements and fix a few issues. It adds foreground color changing for the preview box and shortcuts for selecting most of the extended mode characters. It also adds using the arrow keys to move the edit cursor around, mostly since emulators map the arrow keys to the Sinclair cursor keys (shifted 5 to 8).
I started to change the look a bit more. I don't remember why I used uppercase so much; it gave it a ZX81 look. I think I didn't like the lowercase in the Sinclair font very much, so was avoiding it whereas everyone else was mad about it since it was new and not too many micros at the time had lowercase.
Several small changes, including improvements to the exit screen saying how to use the font. I better optimized the edit key loop to make it more responsive. An improvement in test mode when typing near the end of a line or bottom of the screen.
Further optimization of the edit key loop to make it much better than the last improvement.
First introduction of machine code to help speed some things up. This included
copying the ROM font and decoding the character bytes into bits to make the
magnified array of pixels. The latter took some playing around given how the
system variable DEST behaved to be able to capture the address of the a$
character array. The machine code is loaded from a hex string into a padded line
1 REM statement rather than into high memory which allows a NEW to get rid of
the BASIC program and leave just the font. The machine code was generated with
the z80asm assembler from mcode.asm, then I entered the hex codes into my
loader string.
Switched to using key codes for checking in key loops since quoted tokens get converted to text by listbasic and don't convert back with ZMakeBAS. Added initial specialization for the ZX Spectrum to show the tilde and vertical bar characters in the font display and keyboard selection of them. Refined the view and edit menus.
This changed the MC to not have to poke the number of bytes and addresses for the mcopy routine in favor of just copying the 8 bytes for the selected character using PEEKs and using a short MC routine that copies the whole ROM font. Now the character offset and a$ location are just POKEd into the MC where the addresses are used since they are now only referenced once. Changed the MC loader to print all the hex digits then invert each pair as it loads the bytes to give a progress bar effect.
Added changing the app background color with shift+1 and shift+2.
Added caps lock toggling in test mode.
Fixed not zeroing the d() array when using the clear all bits function, which
was scrambling the subsequent editing.
Changed the quit app to symbol shift+Q (~<=) so I could make
symbol shift+A (STOP) be the shortcut for the tilde character. Also made
symbol shift+S (NOT) the vertical bar shortcut. The copy ROM font function
was moved to symbol shift+E (>=).
Notionally improved support for the ZX Spectrum by making the memory locations less hard-coded and use system variables to get addresses more. Rather than using 64600 for the font location, use the UDG address minus 768 bytes. This lets it work on a 16K Spectrum, however, that is too little RAM to load this program. Also check if RAMTOP needs moving or is it already below the font address. Changed the test mode to not ask for paper and ink color and it just uses the current character preview colors. Fixed a few cosmetic bugs with the menus. Also improved the sample font loader program.
Fixed wrongly labeled forground/background preview color change keys. I'd had
the FG and BG labels reversed this whole time. Switched the MC loader to use
DATA statements. This is simpler, less code, and about twice as fast. Had to
code a variable that says how many bytes there are since we can't do it by
checking the length of the hex string anymore. The loading progress is indicated
by an "x/y" bytes counter.
This version got a variant, 2.2f_64, that will run under the Zebra Systems' OS-64 cartridge ROM that provides the high-res 64 column mode. The screen layout was tweaked to better use the larger screen area. This will probably be a challenge to keep up with the changes to the main program, but being able to output the .tap files as text and diff them should make this easier. I'll probably also modify the code to perhaps minimize the differences with parametric layout values. The memory layout is slightly different when running under OS-64, one of which was the ROM font is at a different address.
- Allow it to run as an AROS program from a .dck cartridge image since we have utilities that can convert a basic program to do so. It just loads the MC below the font. I may just always do that and avoid the REM line storage.
- Detect loaded bytes name and show in title bar
- Add ability to edit UDGs, toggle with shift+0. Separate save/load names.
- Add MC routine to copy UDGs to/from user font area, swapping bytes.
- Add ability to type UDGs in test mode (shift+9)
- Add shift bits up/down/left/right (shift+A/Z/K/L) (BASIC code)
- Add copy/paste bits between characters (symbShift+C/V)
- New MC loader progress bar that doesn't slow the load down much
- Had intended to add MC code for flips and rotates but it is still buggy.
- Added a few REM labels for menu key codes and gosub calls
- Make the UI BG color only cycle around after white back to black rather than shift+1 and shift+2 for back and forth
- Make shift+1 reveal the character bytes (not documented on screen)
- Captures the loaded file name to show at the top and set it when you save
- Allow editing of the UDG characters with shift+9 to switch back and forth. They replace letters A through U, which are indicated with inverse letters, and you just select and edit those. While in UDG mode, the save and load apply to the UDGs only. The UDG filename is kept separately.
- Changed copy ROM chars to e/E/>= in edit mode
- Add extra keys help on ? key in edit mode
- Add h/v flip (not MC) in edit mode: keys h and v
- Add l/r rotate (not MC) in edit mode: keys r and t