query: When did the Chinese writing system develop?
passage: Written Chinese
Various current Chinese characters have been traced back to the late Shang Dynasty about 1200–1050 BC,[6][7][8] but the process of creating characters is thought to have begun some centuries earlier.[9] After a period of variation and evolution, Chinese characters were standardized under the Qin Dynasty (221–206 BC).[10] Over the millennia, these characters have evolved into well-developed styles of Chinese calligraphy.[11] As the varieties of Chinese diverged, a situation of diglossia developed, with speakers of mutually unintelligible varieties able to communicate through writing using Classical Chinese.[12] In the early 20th century, Classical Chinese was replaced in this role by written vernacular Chinese, corresponding to the standard spoken language ("Mandarin"). Although most other varieties of Chinese are not written, there are traditions of written Cantonese, written Shanghainese and written Hokkien, among others.
passage: Chinese typewriter
Hou-Kun Chow (), a mechanical engineer in Shanghai, is credited with inventing the first Chinese typewriter in 1916. His typewriter utilized 4,000 characters. He had studied in the United States like several other Chinese who also contributed to the development of Chinese typewriters. Chow first thought about the practicality of a Chinese typewriter in Boston, while he was inspecting American typewriters as a student of the Massachusetts Institute of Technology. His efforts were initially hindered by a lack of technical assistance in Shanghai.