Desktops Servers Electromechanical Computers Laptops Printers Others Our Friends Abacus Addiator Arithma ADDO Mod 16 ADDO-X 331 Brunsviga 13RK Brunsviga 13ZK Calculator "Superautomat SASL" Euklid Facit 1004 Facit EK Felix Mechanical calculator MADAS Mellita, Model V/16 Monroe Model L200-X Nisa PK 5 Original Produx Calculator Remington Rand Adding Machine Walther DE 100 Walther RM XxX calculator Nisa PK 5 Nisa, 1970 The PK 5 of the Czechoslovak manufacturer Nisa is an electromechanical four-species machine with full keyboard,i.e. there is a separate key column for each of the ten digits of the input unit, i.e. a total of 100 digit keys.