An Overview of Big5 Character Encoding System

The Big5 character encoding system is a widely used character set in East Asia, particularly in Taiwan, Hong Kong, Macau, and mainland China. It was developed by the Electronics Research Group (ERG) at the Institute for Information Industry (III) in the 1980s as an extension of the earlier EUC-KR (Extended Unix Character Set – Korean) encoding standard. The Big5 character set is used to represent Chinese characters, known as Hanzi or Kanji in East Asia.

Origins and Development

The development of the Big5 character encoding system https://big5casinoresort.ca/ began in 1980 at the ERG, a research organization affiliated with the Taiwanese government’s Ministry of Economic Affairs. At that time, there was a growing need for a standardized character set to support the increasing use of Chinese characters in electronic communication, including text editing, word processing, and online publishing.

The initial version of Big5 was released in 1984 as an extension of the EUC-KR encoding standard, which used a 2-byte-per-character (BPC) format. To accommodate the larger number of Chinese characters required for Big5, ERG expanded this to a 3-BPC format and introduced new escape sequences for control codes.

Character Set Structure

The Big5 character set consists of 13 planes or blocks, each containing over 2,000 unique code points representing individual Chinese characters. The first three planes (0xA1-0xFE) are the most frequently used and contain about 10,000 of the most common Hanzi glyphs.

Plane A1-AF is assigned to a set of basic control codes and other special characters that were not part of earlier character sets like EUC-KR. Plane F5-FE contains special Hanzi characters for representing tones in Mandarin Chinese, whereas Plane FF contains control codes similar to those found in the 8-bit C0 block.

Plane FD includes additional logographic elements known as Zhuyin (bopomofo), which were first used by Taiwanese linguist Zheng Zhen Duong. These represent the basic components of Hanzi characters, rather than just a single glyph, and are useful for teaching and inputting Chinese text when keyboards do not have individual keys for each Han character.

In comparison with other widely used East Asian encoding standards like Unicode or SHIFT JIS, Big5 is more compact due to its use of overlapping code points within each plane but also shares similarities with these systems by allowing multiple planes that correspond directly across different alphabets and writing styles.

Limitations and Variations

Although the original intention was for Big5 to be used universally across China, Hong Kong, Macau, and Taiwan as one common character encoding system, variations began arising over time. One of them is known as CNS (Code for Information Interchange), which incorporates 32K byte planes with extra characters in addition to Big5.

Because most early Asian-language electronic devices contained only the original 3-BPC form or used it extensively alongside its predecessor EUC-KR before later adding optional extensions, software support remained inconsistent across regions depending on where and when it was implemented.