Keystone 350 (Berkey Keystone)

The Keystone 350 is an arithmetic calculator with algebraic logic. It has 5 functions, 18 keys, and a gas discharge display.

Facts at a glance:

Feature Value
Type: Arithmetic
Functions: 5
Keys: 18
Logic: Algebraic
Display type: Discharge
Year introduced: 1975

See other calculators by Keystone