Half-width kana and 2/3-width kana were used from pre-computer era. In the early computer era, ASCII is defined as a 7-bit character set and has room for 128 characters. However, since this standard was designed for the United States, it does not contain characters and symbols, such as the yen (¥) symbol needed to represent Japanese currency, nor did it include space for characters from other alphabets, such as kana or kanji – thus Japanese characters could not be "encoded". Further, Japanese characters, both kana and kanji, are drawn on a square grid, while Latin characters are generally written more narrowly – thus Japanese characters could not be "displayed" either.