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
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
.5” height. One of three square root machines produced
by Friden, the others being the SRW and RSR.
sincere thanks to Dr. Robert Baron for the donation
of this machine