-The first VCR was launched in 1956.
-The first videogame, Nin, was released in 1951.
-Computers began its development since the early 1900s.
-The Sony Walkman was a portable audio player released by the Japanese company Sony in 1979.
-Calculators were developed since the beggining of 19th Century.
With all this information, we can state that only Walkman was invented during the 1970.
