Electromechanical calculating machines from the 1960's
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Rotary calculators
Badenia VA-17
Badenia VARE-17
Bohn Contex 55
Cellatron R44SM
Diehl DSR-18
Diehl VSR-18
Facit CA1-13
Friden SBT
Friden SVE
Friden SRW
Friden SRQ
Friden RSR
Hamann 505
Madas 20 BTG
Marchant ABL
Marchant SKA DeciMagic
Marchant Tenkeymatic
Monroe IQ-213
Olympia RA-16

Soemtron 214

Printing calculators



Other calculating devices

References and links



Friden SRQ        
  Friden Inc.
San Leandro, California, USA
  stepped drum
  10 x 11 x 20
Years produced
Price when new
  $1395 in 1964
Size (W x D x H)
  lb. oz. (kg)
  automatic squaring
automatic square roots
  click on photo to enlarge    

This machine is an evolution of the SRW, combining automatic square roots with the ability to automatically square a number. With the separate multiplier keyboard that was used on all Friden rotary calculators, automatic squaring was a significant mechanical challenge. The number from the multiplier keyboard had to be automatically transferred into the main keyboard before the operation could begin. The mechanism required more room than the standard W-line enclosure would allow, so the bottom plate of the machine was unique to this model, giving an additional .5” height. One of three square root machines produced by Friden, the others being the SRW and RSR.

My sincere thanks to Dr. Robert Baron for the donation of this machine