Summa Prima 20 adding machine

An Olivetti Summa Prima 20 adding machine, made in Italy circa,1960s and designed originally in 1949 by Marcelo Nizzoli, who was chief designer for Olivetti for a number of years. The manually operated push button keyboard is laid out for pre-decimal operation and has add, subtract, sub-total and total functions. The base and mechanism are made from pressed metal, the buttons and cover are made from ABS (?). The calculations and total are displayed on a printed paper roll which is struck by metal keys, through an inked ribbon, in the manner of a typewriter.

printed: "olivetti. Made in Italy" (label on top of cover)

printed: "summa PRIMA 20 OLIVETTI. mADE IN iTALY. Fabrique en Italie" (back of case, below printer roll)

AIBDC : 008244