Additional Pictures 


The printed circuit board (PCB) of the SR-56 (right) is shared with the
SR-50A Version 2 (left) and SR-51A Version 2 (center).

The "Clock Generator Patch Area" of two SR-51A Version 2 calculators manufactured in
April 1976 (left) and November 1976 (right).

horizontal rule

If you have additions to the above article please email:

Joerg Woerner, December 21, 2023. No reprints without written permission.