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<div class="moz-cite-prefix">U+2571, U+2572 and U+2573 are 0xA2AC,
0xA2AD and 0xA2AE respectively in Big5 (the dominant pre-Unicode
encoding for Traditional Chinese). They also appear in GBK
(Simplified Chinese) as 0xA875, 0xA876 and 0xA877 respectively,
though GBK is post-Unicode (extending GB2312-as-EUC-CN to include
the entire original URO and some other (non-Hangul) chars from
other CJK encodings, in this case from Big5).<br>
<br>
IBM calls them SH020080, SH030080 and SH040080 respectively (the
"8" here is just a fullwidth attribute, but they don't seem to
appear in single-byte code pages as e.g. SH020000 anywhere). They
appear, unsurprisingly, in the Traditional Chinese code pages, and
in the versions of the Simplified Chinese code pages expanded for
GBK; they also appear in the more expanded versions of Japanese
EBCDIC for some reason.<br>
<br>
Also, yes, U+2571 and U+2572 (but not U+2573) appear in the G2 set
of Videotex Data Syntax 3 / NAPLPS (ITU T.101 Annex D, ANSI
X3.110:1983, CSA T500:1983, FIPS PUB 121), which has ISO-IR
registration numbers 99 (registered by ANSI and later withdrawn in
favour of the redundant 128) and 128 (registered by the ITU).
Although it is itself a modified version of the ISO 6937 set, the
base ISO 6937 set doesn't include these characters.<br>
<br>
--Har<br>
<br>
Rebecca Bettencourt via Unicode wrote:<br>
</div>
<blockquote type="cite" cite="mid:CAH=y87a7SjQHSTesCo0q+afVKPCdtY5qQ6zZm5tHrbwDNom_MQ@mail.gmail.com">
<div dir="ltr">These three box drawing diagonals appear in at
least:
<div>- Amstrad CPC</div>
<div>- Mattel Aquarius</div>
<div>- Atari 8-bit</div>
<div>- MSX</div>
<div>- PETSCII</div>
<div>- Kaypro</div>
<div>- Sharp MZ</div>
<div>- Ohio Scientific</div>
<div>- Robotron<br>
<div><br>
</div>
<div>See page 11 of: <a href="https://www.unicode.org/L2/L2019/19025-aux-LegacyComputingSources.pdf" moz-do-not-send="true">https://www.unicode.org/L2/L2019/19025-aux-LegacyComputingSources.pdf</a>
<div><br>
</div>
<div>See page 5 of: <a href="https://www.unicode.org/L2/L2021/21235-terminals-supplement-sources.pdf" moz-do-not-send="true">https://www.unicode.org/L2/L2021/21235-terminals-supplement-sources.pdf</a><br clear="all">
<div>
<div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><br>
</div>
<div class="gmail_signature" data-smartmail="gmail_signature">They don't appear in
Teletext.</div>
<div class="gmail_signature" data-smartmail="gmail_signature"><br>
</div>
<div class="gmail_signature" data-smartmail="gmail_signature">As to how they came
to be in Unicode originally, I don't know. Probably
some IBM or DEC character set.</div>
<div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><br>
-- Rebecca Bettencourt</div>
</div>
<br>
</div>
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</blockquote>
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