In 1955 Zemanek developed the first complete transistorised computer in Europe, which subsequently calculated a prime number higher than five billion in little over an hour.
The computer was named Mailüfterl (German for "May breeze") in reference to Whirlwind, a computer developed at MIT between 1945 and 1951.
The computer weighed more than half a tonne (1100 pounds) and was twice as wide as a king-sized bed. It has been on display at the Technical Museum of Vienna since 1973.
Zemanek also taught at the University of Vienna, and received numerous awards.
He was President of the International Federation for Information Processing (IFIP), based in Laxenburg near Vienna and founding president of the Austrian Computer Society, as well as a member of the Austrian Academy of Sciences and a recipient of the Medal of Honour for services to the Republic of Austria.
His work with the IBM Laboratory Vienna, also earned him fame – he was crucial in the creation of the formal definition of the programming language PL/I.
In 2003 he was awarded the Cardinal Innitzer prize for his life's work.
Just last year, Zemanek was honoured by Google as part of its Computer Heritage Program, as one of the fathers of modern computing.