There’s a very famous book entitled "The Autobiography of Han Shan." It dates from the 1500’s and you can find translations of it on the web.

www.hsuyun.org/Dharma/zbohy/Literature/HanShan/hanshan-home.html
www.abuddhistlibrary.com/…/Han%20Shan/Autobiography/Han%20Shan%20Autobiography%20and%20Maxims.rtf
www.thezensite.com/ZenTeachings/Translations/TheAutobiographyOfHanShan.pdf

The autobiography features the story of the Zen monk Han Shan, and how he cultivated enlightenment via the method of listening to sound as well as other techniques.

Because of his subsequent samadhi concentration, Han Shan could copy a sutra, recite a mantra, and carry on a conversation simultaneously — ALL at the same time (see his Thirty-third Year (1578-9)). 

Even when people came to try to break his conversation by disturbing him, we would make no error in his text copying or mantra recitation, and could do multiple things at once. Such is just one of the powers of samadhi concentration….it’s not limited to Buddhism, Christianity, Judaism, Taoism, Hinduism or any other school. Whoever cultivates samadhi can do wondrous things.

Why this story?

It seems that you can also train your mind, in a mundane fashion, so that it can carry out multiple tasks at the same time.

This is very interesting — Harry Kahne: Multiple Mentality http://www.rexresearch.com/kahne/kahne.htm . Harry claims that you don’t need an extraordinary mind, just training.

Interesting….