Actually, Zhuyin was used for a number of years before the Latin Pinyin scheme was finalized in 1958, after which it remained as an alternative for people less familiar with the Latin alphabet. Dictionary and reference books[0] published in the mainland used to include Zhuyin well into the 1980s. The characters used for Zhuyin were actually retained in the earliest simplified Chinese character sets (GB 2312-80) for computer typesetting, however by then very few people are still using them over Pinyin. And indeed it gradually faded from public knowledge from there.

[0]:http://img1.gtimg.com/news/pics/hv1/74/203/2056/133743239.pn...