Matty F burst on the scene, and said:

I used an electronic calculator with Nixie tubes in 1962 at
University.
Quite possbly this model:
http://en.wikipedia.org/wiki/Sumlock_ANITA_calculator

Electronic calculators appeared in the '60s but *pocket* calculators
were a product of the '70s.

--
Michaelangelo
www.flickr.com/photos/mikenagel

Self-catering, holiday accommodation in the Scottish Highlands - for
disabled people:
www.woodhead-cottage.co.uk