Facit Electro Mechanical Calculator (1953)

  • Model: Facit Model ESA-0, S/N 349720, 1953
  • Developer: Karl Rudin
  • Manufacturer: Atvidaberg-Facit, Sweden,
  • Released in: 1949-1956


  • Digits- 9 keyboard, 8 counter, 13 accumulator
  • Dimensions- 280W x 260D x 180H
  • Weight- 12.4 kg
  • Functions – Addition/Subtraction/Multiplication/Division
  • Dalton keyboard, green pressed-metal cover
  • Electro-mechanical, pin-wheel calculator.
  • This is an electrically driven machine.


Model ESA (Electric Super-Automat) was the Facit’s first fully-automatic calculator which was built in 1945. This model is an extension of the previous NEA model which implemented with extending the functions to include an automatic 8-digit multiplier. but the manual clearing levers retained the same. From the model ESA-0 engineers have added a motorised clearing mechanism. It included three additional keys at the lower front. The iron frame of this non-printing electric pinwheel calculating machine is printed in dark green color. Fully automatic addition, subtraction, multiplication, and division was available in this calculator. Additionally, clearing of registers was done electrically.

This calculator contains five function keys and three tab keys. The key tops were made of plastic. There is a lever on the front left sets the machine for multiplication, addition, subtraction or division.