
Muldivo 'Mentor' calculator model WSR, 160 c1955.
circa 1955
circa 1955
1957
(1962); 1982
1961
1957
1958
1962
1956
1955
1955
circa 1955
1962
1960
1960
1960
1960
1955
1955; 1830
1955
1955
1954-1955
1959
1955
1955
1957
1962
circa 1960
1957
1955
1960
1960
1958
1956
1955
1954
1957
1955
1962
1958
1956
1961
1956
1956
1960
2000-100 BCE
1961
1957
1957
1962
1957