From: Ben Harris <bjh21@bjh21.me.uk>
Date: Mon, 25 Aug 2014 23:12:06 +0000 (+0100)
Subject: Add my file of odd notes.
X-Git-Tag: bedstead-001.001~9
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=d44f0297eb6044bb8a0d6b9b4c633e10bd0004d9;p=bedstead.git

Add my file of odd notes.
---

diff --git a/NOTES b/NOTES
new file mode 100644
index 0000000..c14c991
--- /dev/null
+++ b/NOTES
@@ -0,0 +1,499 @@
+Pixel aspect ratios: http://www.lurkertech.com/lg/video-systems/#sqnonsq
+
+In 480i, industry convention is that you get square pixels with a pixel
+clock of 12+3/11 MHz.  In 576i, you need 14.75 MHz.  The SAA5050 takes a
+nominal 6MHz clock and uses both edges to output subpixels (duty cycle
+between 0.4 and 0.6).  This means that the nominal pixel aspect ratios
+are 12+3/11:12 for 480i and 14.75:12 for 576i.  These correspond to
+pixel widths of 102.3 and 122.9 respectively.
+
+Precise pixel layouts for mosaic graphics:
+
+Based on a 6x10 grid of pixels:
+
+............  000000111111  ..0000..1111  
+......##....  000000111111  ..0000..1111
+....##..##..  000000111111  ............
+..##......##  222222333333  ..2222..3333
+..##......##  222222333333  ..2222..3333
+..##########  222222333333  ..2222..3333
+..##......##  222222333333  ............
+..##......##  444444555555  ..4444..5555
+............  444444555555  ..4444..5555
+............  444444555555  ............
+
+Mosaic characters are not smoothed, and smoothing also doesn't apply
+between mosaic characters and adjacent alphanumeric characters.
+
+The SAA5050 series is generally compatible with the G0 primary
+character sets defined by ETSI EN 300 706 V1.2.1:
+
+SAA5050: Latin with English option
+SAA5051: Latin with German option
+SAA5052: Latin with Swedish option
+SAA5053: Latin with Italian option
+SAA5054: Latin with French option
+
+SAA5057: Cyrillic (Russian)
+
+There's no ETSI EN 300 706 character set that corresponds to the
+SAA5055.  The ETSI EN 300 706 Hebrew set is almost identical to the
+SAA5056 set, except that the old Sheqel sign on the SAA5056 is
+replaced by the new Sheqel sign in ETSI EN 300 706.
+
+ETSI EN 300 706 to Unicode mapping:
+
+ZVBI, the Zapping teletext decoder has opinions on this:
+
+ * Exceptions:
+ * ETS 300 706 Table 36 Latin National Subset Turkish character
+ * 0x23 Turkish currency symbol is not representable in Unicode,
+ * translated to private code U+E800. Was unable to identify all
+ * Arabic glyphs in Table 44 and 45 Arabic G0 and G2, these are
+ * mapped to private code U+E620 ... U+E67F and U+E720 ... U+E77F
+ * respectively. Table 47 G1 Block Mosaic is not representable
+ * in Unicode, translated to private code U+EE00 ... U+EE7F.
+ * (contiguous form has bit 5 set, separate form cleared).
+ * Table 48 G3 Smooth Mosaics and Line Drawing Set is not
+ * representable in Unicode, translated to private code U+EF20
+ * ... U+EF7F.
+ *
+ * Note that some Teletext character sets contain complementary
+ * Latin characters. For example the Greek capital letters Alpha
+ * and Beta are reused as Latin capital letter A and B, while a
+ * separate code exists for Latin capital letter C. This function
+ * is unable to distinguish between uses, so it will always translate
+ * Greek A and B to Alpha and Beta, C to Latin C.
+ *
+ * Private codes U+F000 ... U+F7FF are reserved for DRCS.
+
+Latin G0 primary set is mostly ASCII, with the exception of:
+
+0x24 0x00A4 # CURRENCY SIGN
+0x7C 0x00A6 # BROKEN BAR
+0x7F 0x25A0 # BLACK SQUARE
+
+G0 national options each vary a few characters:
+
+Czech/Slovak:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x016F # LATIN SMALL LETTER U WITH RING ABOVE
+0x40 0x010D # LATIN SMALL LETTER C WITH CARON
+0x5B 0x0165 # LATIN SMALL LETTER T WITH CARON
+0x5C 0x017E # LATIN SMALL LETTER Z WITH CARON
+0x5D 0x00FD # LATIN SMALL LETTER Y WITH ACUTE
+0x5E 0x00ED # LATIN SMALL LETTER I WITH ACUTE
+0x5F 0x0159 # LATIN SMALL LETTER R WITH CARON
+0x60 0x00E9 # LATIN SMALL LETTER E WITH ACUTE
+0x7B 0x00E1 # LATIN SMALL LETTER A WITH ACUTE
+0x7C 0x011B # LATIN SMALL LETTER E WITH CARON
+0x7D 0x00FA # LATIN SMALL LETTER U WITH ACUTE
+0x7E 0x0161 # LATIN SMALL LETTER S WITH CARON
+
+English:
+0x23 0x00A3 # POUND SIGN
+0x24 0x0024 # DOLLAR SIGN
+0x40 0x0040 # COMMERCIAL AT
+0x5B 0x2190 # LEFTWARDS ARROW
+0x5C 0x00BD # VULGAR FRACTION ONE HALF
+0x5D 0x2192 # RIGHTWARDS ARROW
+0x5E 0x2191 # UPWARDS ARROW
+0x5F 0x0023 # NUMBER SIGN
+0x60 0x2014 # EM DASH
+0x7B 0x00BC # VULGAR FRACTION ONE QUARTER
+0x7C 0x2016 # DOUBLE VERTICAL LINE
+0x7D 0x00BE # VULGAR FRACTION THREE QUARTERS
+0x7E 0x00F7 # DIVISION SIGN
+
+Estonian:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x00F5 # LATIN SMALL LETTER O WITH TILDE
+0x40 0x0160 # LATIN CAPITAL LETTER S WITH CARON
+0x5B 0x00C4 # LATIN CAPITAL LETTER A WITH DIAERESIS
+0x5C 0x00D6 # LATIN CAPITAL LETTER O WITH DIAERESIS
+0x5D 0x017D # LATIN CAPITAL LETTER Z WITH CARON
+0x5E 0x00DC # LATIN CAPITAL LETTER U WITH DIAERESIS
+0x5F 0x00D5 # LATIN CAPITAL LETTER O WITH TILDE
+0x60 0x0161 # LATIN SMALL LETTER S WITH CARON
+0x7B 0x00E4 # LATIN SMALL LETTER A WITH DIAERESIS
+0x7C 0x00F6 # LATIN SMALL LETTER O WITH DIAERESIS
+0x7D 0x017E # LATIN SMALL LETTER Z WITH CARON
+0x7E 0x00FC # LATIN SMALL LETTER U WITH DIAERESIS
+
+French:
+0x23 0x00E9 # LATIN SMALL LETTER E WITH ACUTE
+0x24 0x00EF # LATIN SMALL LETTER I WITH DIAERESIS
+0x40 0x00E0 # LATIN SMALL LETTER A WITH GRAVE
+0x5B 0x00EB # LATIN SMALL LETTER E WITH DIAERESIS
+0x5C 0x00EA # LATIN SMALL LETTER E WITH CIRCUMFLEX
+0x5D 0x00F9 # LATIN SMALL LETTER U WITH GRAVE
+0x5E 0x00EE # LATIN SMALL LETTER I WITH CIRCUMFLEX
+0x5F 0x0023 # NUMBER SIGN
+0x60 0x00E8 # LATIN SMALL LETTER E WITH GRAVE
+0x7B 0x00E2 # LATIN SMALL LETTER A WITH CIRCUMFLEX
+0x7C 0x00F4 # LATIN SMALL LETTER O WITH CIRCUMFLEX
+0x7D 0x00FB # LATIN SMALL LETTER U WITH CIRCUMFLEX
+0x7E 0x00E7 # LATIN SMALL LETTER C WITH CEDILLA
+
+German:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x0024 # DOLLAR SIGN
+0x40 0x00A7 # SECTION SIGN
+0x5B 0x00C4 # LATIN CAPITAL LETTER A WITH DIAERESIS
+0x5C 0x00D6 # LATIN CAPITAL LETTER O WITH DIAERESIS
+0x5D 0x00DC # LATIN CAPITAL LETTER U WITH DIAERESIS
+0x5E 0x005E # CIRCUMFLEX ACCENT
+0x5F 0x005F # LOW LINE
+0x60 0x00B0 # DEGREE SIGN
+0x7B 0x00E4 # LATIN SMALL LETTER A WITH DIAERESIS
+0x7C 0x00F6 # LATIN SMALL LETTER O WITH DIAERESIS
+0x7D 0x00FC # LATIN SMALL LETTER U WITH DIAERESIS
+0x7E 0x00DF # LATIN SMALL LETTER SHARP S
+
+Italian:
+0x23 0x00A3 # POUND SIGN
+0x24 0x0024 # DOLLAR SIGN
+0x40 0x00E9 # LATIN SMALL LETTER E WITH ACUTE
+0x5B 0x00B0 # DEGREE SIGN
+0x5C 0x00E7 # LATIN SMALL LETTER C WITH CEDILLA
+0x5D 0x2192 # RIGHTWARDS ARROW
+0x5E 0x2191 # UPWARDS ARROW
+0x5F 0x0023 # NUMBER SIGN
+0x60 0x00F9 # LATIN SMALL LETTER U WITH GRAVE
+0x7B 0x00E0 # LATIN SMALL LETTER A WITH GRAVE
+0x7C 0x00F2 # LATIN SMALL LETTER O WITH GRAVE
+0x7D 0x00E8 # LATIN SMALL LETTER E WITH GRAVE
+0x7E 0x00EC # LATIN SMALL LETTER I WITH GRAVE
+
+Lettish/Lithuanian:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x0024 # DOLLAR SIGN
+0x40 0x0160 # LATIN CAPITAL LETTER S WITH CARON
+0x5B 0x0117 # LATIN SMALL LETTER E WITH DOT ABOVE
+0x5C 0x0229 # LATIN SMALL LETTER E WITH CEDILLA
+# should 0x5C be U+0119 LATIN SMALL LETTER E WITH OGONEK?
+0x5D 0x017D # LATIN CAPITAL LETTER Z WITH CARON
+0x5E 0x010D # LATIN SMALL LETTER C WITH CARON
+0x5F 0x016B # LATIN SMALL LETTER U WITH MACRON
+0x60 0x0161 # LATIN SMALL LETTER S WITH CARON
+0x7B 0x0105 # LATIN SMALL LETTER A WITH OGONEK
+0x7C 0x0173 # LATIN SMALL LETTER U WITH OGONEK
+0x7D 0x017E # LATIN SMALL LETTER Z WITH CARON
+0x7E 0x012F # LATIN SMALL LETTER I WITH OGONEK
+
+Polish:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x0144 # LATIN SMALL LETTER N WITH ACUTE
+0x40 0x0105 # LATIN SMALL LETTER A WITH OGONEK
+0x5B 0x01B5 # LATIN CAPITAL LETTER Z WITH STROKE
+0x5C 0x015A # LATIN CAPITAL LETTER S WITH ACUTE
+0x5D 0x0141 # LATIN CAPITAL LETTER L WITH STROKE
+0x5E 0x0107 # LATIN SMALL LETTER C WITH ACUTE
+0x5F 0x00F3 # LATIN SMALL LETTER O WITH ACUTE
+0x60 0x0119 # LATIN SMALL LETTER E WITH OGONEK
+0x7B 0x017C # LATIN SMALL LETTER Z WITH DOT ABOVE
+0x7C 0x015B # LATIN SMALL LETTER S WITH ACUTE
+0x7D 0x0142 # LATIN SMALL LETTER L WITH STROKE
+0x7E 0x017A # LATIN SMALL LETTER Z WITH ACUTE
+
+Portuguese/Spanish:
+0x23 0x00E7 # LATIN SMALL LETTER C WITH CEDILLA
+0x24 0x0024 # DOLLAR SIGN
+0x40 0x00A1 # INVERTED EXCLAMATION MARK
+0x5B 0x00E1 # LATIN SMALL LETTER A WITH ACUTE
+0x5C 0x00E9 # LATIN SMALL LETTER E WITH ACUTE
+0x5D 0x00ED # LATIN SMALL LETTER I WITH ACUTE
+0x5E 0x00F3 # LATIN SMALL LETTER O WITH ACUTE
+0x5F 0x00FA # LATIN SMALL LETTER U WITH ACUTE
+0x60 0x00BF # INVERTED QUESTION MARK
+0x7B 0x00FC # LATIN SMALL LETTER U WITH DIAERESIS
+0x7C 0x00F1 # LATIN SMALL LETTER N WITH TILDE
+0x7D 0x00E8 # LATIN SMALL LETTER E WITH GRAVE
+0x7E 0x00E0 # LATIN SMALL LETTER A WITH GRAVE
+
+Rumanian:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x00A4 # CURRENCY SIGN
+0x40 0x0162 # LATIN CAPITAL LETTER T WITH CEDILLA
+0x5B 0x00C2 # LATIN CAPITAL LETTER A WITH CIRCUMFLEX
+0x5C 0x015E # LATIN CAPITAL LETTER S WITH CEDILLA
+0x5D 0x01CD # LATIN CAPITAL LETTER A WITH CARON
+# should 0x5D be U+0102 LATIN CAPITAL LETTER A WITH BREVE?
+0x5E 0x00CD # LATIN CAPITAL LETTER I WITH ACUTE
+0x5F 0x0131 # LATIN SMALL LETTER DOTLESS I
+0x60 0x0163 # LATIN SMALL LETTER T WITH CEDILLA
+0x7B 0x00E2 # LATIN SMALL LETTER A WITH CIRCUMFLEX
+0x7C 0x015F # LATIN SMALL LETTER S WITH CEDILLA
+0x7D 0X01CE # LATIN SMALL LETTER A WITH CARON
+# should 0x7D be U+0103 LATIN SMALL LETTER A WITH BREVE?
+0x7E 0x00EE # LATIN SMALL LETTER I WITH CIRCUMFLEX
+
+Serbian/Croation/Slovenian:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x00CB # LATIN CAPITAL LETTER E WITH DIAERESIS
+0x40 0x010C # LATIN CAPITAL LETTER C WITH CARON
+0x5B 0x0106 # LATIN CAPITAL LETTER C WITH ACUTE
+0x5C 0x017D # LATIN CAPITAL LETTER Z WITH CARON
+0x5D 0x00D0 # LATIN CAPITAL LETTER ETH
+# should 0x5D be U+0110 LATIN CAPITAL LETTER D WITH STROKE?
+0x5E 0x0160 # LATIN CAPITAL LETTER S WITH CARON
+0x5F 0x00EB # LATIN SMALL LETTER E WITH DIAERESIS
+0x60 0x010D # LATIN SMALL LETTER C WITH CARON
+0x7B 0x0107 # LATIN SMALL LETTER C WITH ACUTE
+0x7C 0x017E # LATIN SMALL LETTER Z WITH CARON
+0x7D 0x00F0 # LATIN SMALL LETTER ETH
+# should 0x5F be U+0111 LATIN SMALL LETTER D WITH STROKE?
+0x7E 0x0161 # LATIN SMALL LETTER S WITH CARON
+
+Swedish/Finnish:
+0x23 0x0023 # NUMBER SIGN
+0x24 0x00A4 # CURRENCY SIGN
+0x40 0x00C9 # LATIN CAPITAL LETTER E WITH ACUTE
+0x5B 0x00C4 # LATIN CAPITAL LETTER A WITH DIAERESIS
+0x5C 0x00D6 # LATIN CAPITAL LETTER O WITH DIAERESIS
+0x5D 0x00C5 # LATIN CAPITAL LETTER A WITH RING ABOVE
+0x5E 0x00DC # LATIN CAPITAL LETTER U WITH DIAERESIS
+0x5F 0x005F # LOW LINE
+0x60 0x00E9 # LATIN SMALL LETTER E WITH ACUTE
+0x7B 0x00E4 # LATIN SMALL LETTER A WITH DIAERESIS
+0x7C 0x00F6 # LATIN SMALL LETTER O WITH DIAERESIS
+0x7D 0x00E5 # LATIN SMALL LETTER A WITH RING ABOVE
+0x7E 0x00FC # LATIN SMALL LETTER U WITH DIAERESIS
+
+Turkish:
+0x23 0xE800 # <private use>
+0x24 0x011F # LATIN SMALL LETTER G WITH BREVE
+0x40 0x0130 # LATIN CAPITAL LETTER I WITH DOT ABOVE
+0x5B 0x015E # LATIN CAPITAL LETTER S WITH CEDILLA
+0x5C 0x00D6 # LATIN CAPITAL LETTER O WITH DIAERESIS
+0x5D 0x00C7 # LATIN CAPITAL LETTER C WITH CEDILLA
+0x5E 0x00DC # LATIN CAPITAL LETTER U WITH DIAERESIS
+0x5F 0x011E # LATIN CAPITAL LETTER G WITH BREVE
+0x60 0x0131 # LATIN SMALL LETTER DOTLESS I
+0x7B 0x015F # LATIN SMALL LETTER S WITH CEDILLA
+0x7C 0x00F6 # LATIN SMALL LETTER O WITH DIAERESIS
+0x7D 0x00E7 # LATIN SMALL LETTER C WITH CEDILLA
+0x7E 0x00FC # LATIN SMALL LETTER U WITH DIAERESIS
+
+Latin G2 supplementary set:
+0x00A0 # NO-BREAK SPACE
+0x00A1 # INVERTED EXCLAMATION MARK
+0x00A2 # CENT SIGN
+0x00A3 # POUND SIGN
+0x0024 # DOLLAR SIGN
+0x00A5 # YEN SIGN
+0x0023 # NUMBER SIGN
+0x00A7 # SECTION SIGN
+0x00A4 # CURRENCY SIGN
+0x2018
+0x201C
+0x00AB # LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
+0x2190
+0x2191
+0x2192
+0x2193
+0x00B0 # DEGREE SIGN
+0x00B1 # PLUS-MINUS SIGN
+0x00B2 # SUPERSCRIPT TWO
+0x00B3 # SUPERSCRIPT THREE
+0x00D7 # MULTIPLICATION SIGN
+0x00B5 # MICRO SIGN
+0x00B6 # PILCROW SIGN
+0x00B7 # MIDDLE DOT
+0x00F7 # DIVISION SIGN
+0x2019
+0x201D
+0x00BB # RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
+0x00BC # VULGAR FRACTION ONE QUARTER
+0x00BD # VULGAR FRACTION ONE HALF
+0x00BE # VULGAR FRACTION THREE QUARTERS
+0x00BF # INVERTED QUESTION MARK
+0x0020 # SPACE
+0x02CB
+0x02CA
+0x02C6
+0x02DC
+0x02C9
+0x02D8
+0x02D9
+0x00A8 # DIAERESIS
+0x002E # FULL STOP
+0x02DA
+0x02CF
+0x02CD
+0x02DD
+0x02DB
+0x02C7
+0x2014
+0x00B9 # SUPERSCRIPT ONE
+0x00AE # REGISTERED SIGN
+0x00A9 # COPYRIGHT SIGN
+0x2122
+0x266A
+0x20A0
+0x2030
+0x0251
+0x0020
+0x0020
+0x0020
+0x215B
+0x215C
+0x215D
+0x215E
+0x2126
+0x00C6 # LATIN CAPITAL LETTER AE
+0x00D0 # LATIN CAPITAL LETTER ETH
+# should this be U+0110 LATIN CAPITAL LETTER D WITH STROKE? See T.51.
+0x00AA # FEMININE ORDINAL INDICATOR
+0x0126 # LATIN CAPITAL LETTER H WITH STROKE 
+0x0020
+0x0132 # LATIN CAPITAL LIGATURE IJ;
+0x013F
+0x0141
+0x00D8 # LATIN CAPITAL LETTER O WITH STROKE
+0x0152
+0x00BA # MASCULINE ORDINAL INDICATOR
+0x00DE # LATIN CAPITAL LETTER THORN
+0x0166
+0x014A
+0x0149
+0x0138
+0x00E6 # LATIN SMALL LETTER AE
+0x0111
+0x00F0 # LATIN SMALL LETTER ETH
+0x0127
+0x0131
+0x0133
+0x0140
+0x0142
+0x00F8
+0x0153
+0x00DF # LATIN SMALL LETTER SHARP S
+0x00FE # LATIN SMALL LETTER THORN
+0x0167
+0x014B
+0x25A0
+
+Cyrillic Russian option:
+0x042E # CYRILLIC CAPITAL LETTER YU
+0x0410 # CYRILLIC CAPITAL LETTER A
+0x0411 # CYRILLIC CAPITAL LETTER BE
+0x0426 # CYRILLIC CAPITAL LETTER TSE
+0x0414 # CYRILLIC CAPITAL LETTER DE
+0x0415 # CYRILLIC CAPITAL LETTER IE
+0x0424 # CYRILLIC CAPITAL LETTER EF
+0x0413 # CYRILLIC CAPITAL LETTER GHE
+0x0425 # CYRILLIC CAPITAL LETTER HA
+0x0418 # CYRILLIC CAPITAL LETTER I
+0x040D # CYRILLIC CAPITAL LETTER I WITH GRAVE
+# Should be U+0419 CYRILLIC CAPITAL LETTER SHORT I ?
+0x041A # CYRILLIC CAPITAL LETTER KA
+0x041B # CYRILLIC CAPITAL LETTER EL
+0x041C # CYRILLIC CAPITAL LETTER EM
+0x041D # CYRILLIC CAPITAL LETTER EN
+0x041E # CYRILLIC CAPITAL LETTER O
+0x041F # CYRILLIC CAPITAL LETTER PE
+0x042F # CYRILLIC CAPITAL LETTER YA
+0x0420 # CYRILLIC CAPITAL LETTER ER
+0x0421 # CYRILLIC CAPITAL LETTER ES
+0x0422 # CYRILLIC CAPITAL LETTER TE
+0x0423 # CYRILLIC CAPITAL LETTER U
+0x0416 # CYRILLIC CAPITAL LETTER ZHE
+0x0412 # CYRILLIC CAPITAL LETTER VE
+0x042C # CYRILLIC CAPITAL LETTER SOFT SIGN
+0x042A # CYRILLIC CAPITAL LETTER HARD SIGN
+0x0417 # CYRILLIC CAPITAL LETTER ZE
+0x0428 # CYRILLIC CAPITAL LETTER SHA
+0x042D # CYRILLIC CAPITAL LETTER E
+0x0429 # CYRILLIC CAPITAL LETTER SHCHA
+0x0427 # CYRILLIC CAPITAL LETTER CHE
+0x042B # CYRILLIC CAPITAL LETTER YERU
+0x044E # 
+0x0430 # 
+0x0431 # 
+0x0446 # 
+0x0434 # 
+0x0435 # 
+0x0444 # 
+0x0433 # 
+0x0445 # 
+0x0438 # 
+0x045D # 
+0x043A # 
+0x043B # 
+0x043C # 
+0x043D # 
+0x043E # 
+0x043F # 
+0x044F # 
+0x0440 # 
+0x0441 # 
+0x0442 # 
+0x0443 # 
+0x0436 # 
+0x0432 # 
+0x044C # 
+0x044A # 
+0x0437 # 
+0x0448 # 
+0x044D # 
+0x0449 # 
+0x0447 # 
+0x25A0 # 
+
+Hebrew:
+  0x2190u, 0x00BDu, 0x2192u, 0x2191u, 0x0023u,
+  0x05D0u, 0x05D1u, 0x05D2u, 0x05D3u, 0x05D4u, 0x05D5u, 0x05D6u, 0x05D7u, 0x05D8u, 0x05D9u, 0x05DAu, 0x05DBu, 0x05DCu, 0x05DDu, 0x05DEu, 0x05DFu,
+  0x05E0u, 0x05E1u, 0x05E2u, 0x05E3u, 0x05E4u, 0x05E5u, 0x05E6u, 0x05E7u, 0x05E8u, 0x05E9u, 0x05EAu, 0x20AAu, 0x2016u, 0x00BEu, 0x00F7u, 0x25A0u
+
+
+ZVBI doesn't have a mapping for Arabic characters, but maybe we can.
+
+0x20 0x0020
+0x21 0x0021
+0x22 0x0022
+0x23 0x00A3
+0x24 0x00A4
+0x25 0x0025
+
+0x40 0xFE94 # ARABIC LETTER TEH MARBUTA FINAL FORM
+0x41 0xFE80 # ARABIC LETTER HAMZA ISOLATED FORM
+0x42 0xFE92 # ARABIC LETTER BEH MEDIAL FORM
+0x43 0xFE8F # ARABIC LETTER BEH ISOLATED FORM (also final?)
+0x44 0xFE98 # ARABIC LETTER TEH MEDIAL FORM
+0X45 0xFE95 # ARABIC LETTER TEH ISOLATED FORM (also final?)
+0x46 0xFE8E # ARABIC LETTER ALEF FINAL FORM
+0x47 0xFE8D # ARABIC LETTER ALEF ISOLATED FORM
+0x48 0xFE91 # ARABIC LETTER BEH INITIAL FORM
+0x49
+0x4A 0xFE97 # ARABIC LETTER TEH INITIAL FORM
+0x4B 0xFE9B # ARABIC LETTER THEH INITIAL FORM
+0x4C 0xFE9F # ARABIC LETTER JEEM INITIAL FORM
+0x4D 0xFEA3 # ARABIC LETTER HAH INITIAL FORM
+0x4E 0xFEA7 # ARABIC LETTER KHAH INITIAL FORM
+0x4F
+0x50 0x0631 # ARABIC LETTER REH (final and isolated)
+0x51 0x0630 # ARABIC LETTER THAL (final and isolated)
+0x52 0xFEB3 # ARABIC LETTER SEEN INITIAL FORM (also medial)
+0x53 0xFEB7 # ARABIC LETTER SHEEN INITIAL FORM (also medial)
+
+0x5B 0xFE9C # ARABIC LETTER THEH MEDIAL FORM
+0x5C 0xFEA0 # ARABIC LETTER JEEM MEDIAL FORM
+0x5D 0xFEA4 # ARABIC LETTER HAH MEDIAL FORM
+0x5E 0xFEA8 # ARABIC LETTER KHAH MEDIAL FORM
+
+0x6B 0xFE99 # ARABIC LETTER THEH ISOLATED FORM (also final?)
+0x6C 0xFE9D # ARABIC LETTER JEEM ISOLATED FORM (also final?)
+0x6D 0xFEA1 # ARABIC LETTER HAH ISOLATED FORM (also final?)
+0x6E 0xFEA5 # ARABIC LETTER KHAH ISOLATED FORM (also final?)
+
+Teletext mosaic graphics are largely not represented in Unicode, but
+there are a few characters that are already there for 4-cell mosaics:
+
+U+0020 SPACE
+U+2588 FULL BLOCK
+U+258C LEFT HALF BLOCK
+U+2590 RIGHT HALF BLOCK
+
+ITU-T Recommendation T.100 is another standard that encodes 6-cell
+mosaic graphics.