P100 GALAX.XYZ 100 Mon 1 Jan 00:00/00
Amazing new way to browse the web 110
New font resurrects Teletext...... 201
No images are used on this page!
This page uses a TrueType font to show
Teletext text and graphics. If it does
not display correctly, try this version
with static images.
You can use this font to create
authentic looking Teletext web pages.
Teletext font by 3d@galax.xyz 2014
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A few handy utilities:
Convert raw Teletext for the web
(includes sample pages)
Draw Teletext graphics
Generate double-height text
Teletext character set table
The complete Teletext specification
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The font is available with pixels in
several aspect ratios, with square
pixels and then with aspect ratios 10%
to 40% wider than they are high:
MODE7GX0.TTF 1.0:1 Square pixels
MODE7GX1.TTF 1.1:1
MODE7GX2.TTF 1.2:1
MODE7GX3.TTF 1.3:1 * default *
MODE7GX4.TTF 1.4:1
These versions might help with IE
compatibility:
MODE7GX0.EOT 1.0:1
MODE7GX1.EOT 1.1:1
MODE7GX2.EOT 1.2:1
MODE7GX3.EOT 1.3:1
MODE7GX4.EOT 1.4:1
This page uses MODE7GX3.TTF as that
gives a BBC Micro MODE 7 screen with an
aspect ratio very close to 4:3 {1}. It
looks very close to the Teletext display
of a typical TV as well.
This stylesheet is used by this page and
the html generated by the tools above:
TELETEXT.CSS
{1} The characters are 6 by 10 logical
blocks, and the screen is 25 rows of
40 chars. (40*6*1.3)/(25*10)=1.248 |
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Regular Height Double Height
0123456789ABCDEF 0123456789ABCDEF
0000 E020
0010 E120
0020 !"#$%&'()*+,-./ E030
0030 0123456789:;<=>? E130
0040 @ABCDEFGHIJKLMNO E040
0050 PQRSTUVWXYZ[\]^_ E140
0060 `abcdefghijklmno E050
0070 pqrstuvwxyz{|}~ E150
0080 E060
0090 E160
00A0 £ E070
00B0 °±²³´µ¶·¸¹º»¼½¾¿ E170
00C0 ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏ E0A0
00D0 ÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞß E1A0
00E0 àáâãäåæçèéêëìíîï E0B0
00F0 ðñòóôõö÷øùúûüýþÿ E1B0
0123456789ABCDEF E0F0
E1F0
0123456789ABCDEF
Contiguous Separated
0123456789ABCDEF 0123456789ABCDEF
E200 E2C0
E210 E2D0
E220 E2E0
E230 E2F0
0123456789ABCDEF 0123456789ABCDEF
Double Height Double Height Sep.
0123456789ABCDEF 0123456789ABCDEF
E240 E300
E280 E340
E250 E310
E290 E350
E260 E320
E2A0 E360
E270 E330
E2B0 E370
0123456789ABCDEF 0123456789ABCDEF |
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Calculating Alpha Character Values
Characters in the range 00-FF hex (0-255
decimal) use their normal Unicode
values. Note that the position of some
characters is different from their ASCII
value and/or their value assigned b the
TELETEXT standard.
Add E000 hex (57344 decimal) to the
original char for Double Height - Upper,
and add E100 hex (57600 decimal) for
Double Height - Lower.
For example, to display a double height
capital A, which has the code 41 hex
(65 decimal), use the codes E041 and
E141 hex (57409 and 57665 decimal):
E041 = 41 + E000
E151 = 41 + E100
57409 = 65 + 57344
57665 = 65 + 57600
Calculating Graphic Block Char Values
The 64 standard graphics blocks start
at E200 hex (57856 decimal). Each block
is character into 6 blocks. Add on
these values for each block that is on:
Hex Decimal
1 2 1 2
4 8 4 8
1020 1632
For example the code for character is
E219 hex (57881 decimal):
E219 = E200 + 1 + 8 + 10
57881 = 57856 + 1 + 8 + 16
Add on 40 hex (64 decimal) for Double
Height Upper characters, and 80 hex
(128 decimal) for Double Height Lower.
For separated graphic characters add on
C0 hex (192 decimal). This can be com-
bined with double height. For example to
display the character in double height
and separated, use the codes E319 and
E359 hex (58137 and 58201 decimal):
E319 = E219 + 40 + C0
E359 = E219 + 80 + C0
58137 = 57881 + 64 + 192
58201 = 57881 + 128 + 192
Note that the TELETEXT standard uses 64
(40 hex) for the value of the lower
right pixel within the graphics block
when calculating graphics characters.
A Few Notes
The Font was based on ModeSeven by
Andrew Bulhak. I added the double
height characters, all of the various
graphics blocks, and fixed a few
errors. I created this because I
couldn't find a free font that included
the graphics block characters, someone
might have created one before though.
The advantage of this approach over one
that uses images for each of the
graphics characters is that the font
file itself is relatively small, and the
browser doesn't have to download many
hundreds of small images. Teletext pages
are often rendered as a single image,
but the problem with that is that the
text can't be copied, searched, or
indexed- it's more hassle to maintain
than simple static HTML fiiles too.
The main negative aspect of my approach
(using a font over images) is that sup-
port for the @font-face attribute is
still a bit patchy. This page should
work fine in modern browsers however.
This stylesheet allows characters to be
arranged in many ways which would be
impossible in the standard Mode 7
Teletext screen. For example, the
character that changes the foreground
colour causes a space in the page, and
changing the background colour causes
two spaces. If you are looking to
recreate an authentic Teletext web page
you must pay attention to these limit-
ations.
Mode 7 is 25 rows of 40 characters. The
first character on each row is usually
blank, which allows first character to
be use to set the foreground or back-
ground colour on any row while still
aligning the left edge of the text.
The values of the graphical characters
in the Teletext character set can also
be calculated by assigning a power of 2
to each of the 6 sub-blocks, but the
bottom right sub-block is assigned 64
where I used 32.
If you are crazy enough to do the calc-
ulations by hand as I did for this
page, you will find performing the
calculations in hex much simpler than
in decimal- the examples above should
be enough to demonstrate this. I added
the decimal equivalents for people who
aren't interested in learning to count
in hexadecimal just to use this font.
Using this font and stylesheet you can
do things that are illegal within the
TELETEXT standard, such as two-colour
double height text (which the BBC
Micro's MODE 7 allows too), black fore-
ground, and instant changes of back-
ground and foreground colours that would
require empty spaces on a TELETEXT page
or MODE 7 screen.
This font is free to use in non-
commercial projects. I would appreciate
a credit and notification that you are
using it. Let me know if you see any
errors, or have any other feedback!
Teletext font by 3d@galax.xyz 2014
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