Table of Content

• Abstract
• Why we need EUDC
• BIG-5 Encoding Scheme
• What are HKUST EUDC
• Current Situation
• EUDC Migration Issues
• Future EUDC Adoption
• Installing HKUST EUDC

• The difference in glyphs

Strictly speaking, character carries the meaning while glyph is a representation of character. A character may have more than one glyphs. Examples are: "" vs. "", "" vs. "", "" vs. ""...etc. All these pairs are actually the same character with different glyphs. However, in current system implementations, one character encoding can only refer to one glyph in presentation. There is no way that we can store multiple glyphs in one single character encoding space. The only solution is to define a new dummy character with the required glyph.

• Regional cultural difference

Hong Kong, with its unique cultural history, has "invented" a rich set of Chinese characters that were not included in both China GB-2312 and Taiwan BIG-5 encoding schemes. Examples are "", "", "" etc. All these characters need to be defined in additional to the established encoding schemes.

• The culture is evolving

More and more new characters will arise from the evolving cultural advancement. Ancient Chinese characters will no longer exist in contemporary documents. New characters may arise from processes like character simplification, advances in professional dictionaries. All these characters need to be defined before they are incorporated into encoding schemes.

Note :

• 0xA1 means a single character with Hexadecimal code "A1"
• 0xA440 means two characters, the first character has Hexadecimal code "A1", while the second character has Hexadecimal code "40".

During the time that we rolled out ETen Chinese system on our network environment, there was no EUDC standard established in the region. As a result, ITSC selected the 3^rd segment in the EUDC area of BIG-5 encoding scheme and created our own set of Chinese characters. The following table lists the 152 HKUST EUDC and its encoding as at 11-5-1999.

Eten DOS System (倚天中文系統)

Chinese Windows 3.1

RichWin 4.2+/RichWin 97

Chinese Windows 95

• The EUDC character set developed by R&B company which is the richest BIG-5 EUDC character set available on the market at the time we implemented Chinese Windows 95.
• This set of HKUST EUDC was created as at March 96. There was no further enhancement since then.
• GCCS (Government Chinese Character Set) published by ITSD in 1995, it serves the standard for information exchange within government. The adoption of this character set in Hong Kong shows that it will become de-facto standard in the region.

From ETen to Chinese Windows 3.1

There is no conversion available from ETen EUDC to Chinese Windows 3.1 EUDC for the characters fall in EUDC segment 1 & 2. If the document was created in ETen environment with EUDC, there might not be a corresponding character in Chinese Windows 3.1.

A tricky conversion that one may adopt is to make use of the conversion program (繁簡體轉換程式) available in ETen Chinese system. This program will convert a text file with Chinese characters in EUDC segment 1 & 2 to standard BIG-5. Then one may open it in Chinese Windows 3.1 to read the document.

Note that there are 12 characters less in Chinese Windows 3.1 environment since the EUDC created in Chinese Windows 3.1 was as at Mar, 96.

From ETen to RichWin 4.2+/RichWin 97

The EUDC creation tool that comes with RichWin 4.2+/RichWin 97 only supports creating characters in GB locale. Hence HKUST EUDC cannot be ported to RichWin system.

There is no conversion tools for converting document created in ETen with EUDC to RichWin at all.

Remark: To make RichWin properly support GCCS EUDC, one should install the additional font which is available in RichWin installation directory.

From ETen to Chinese Windows 95

Similar to that of Chinese Windows 3.1, there is no conversion available from ETen EUDC to Chinese Windows 95 EUDC for the characters fall in EUDC region 1 & 2. However, the same trick of converting character in ETen system also applies.

From Chinese Windows 3.1 to Chinese Windows 95

A special EUDC conversion utility program is available in Chinese Windows 95 platform. It can basically convert a text file with R&B EUDC encoding to GCCS encoding and remain characters in other regions (including HKUST EUDC) intact. However, the conversion is not a complete mapping, since there are some characters defined in R&B EUDC but still missing in GCCS EUDC.

One major drawback of using such conversion tool is that user will find loss in the formatting of the original document since the tool only converts text file.

From RichWin 4.2+/RichWin 97 to Chinese Windows 95

No conversion is necessary at all. The two systems both support GCCS EUDC. Chinese Windows 95 has richer EUDC set as it is incorporated with HKUST EUDC.

Currently, GCCS EUDC has 3,049 Chinese characters defined and is growing at a rate of around 300 characters per year. Though the Chinese system vendors may not catch up the updating pace, it is expected to be a semi de-facto encoding standard in Hong Kong.

Detailed study on HKUST EUDC reveals that only 13 out of 152 characters are missing in GCCS EUDC. And most of these 13 characters are simply different glyphs of other defined characters.

To avoid further distraction from the GCCS EUDC, migration to Chinese Windows 95 platform will definitely provide a solution to effective Chinese information exchange.

To conclude, sticking to GCCS EUDC standard will help to obtain richest set of traditional Chinese characters. It will in turn meet the regional need for Chinese characters. One will also find that adopting such standard may facilitate document exchange not within the campus but thoughout the SAR.