12 October 2009 @ 8:21Texas Instruments SR-51A Calculator
The mid-1970′s found my father in college and in need of a good scientific calculator. Like many people, he found the HP calculators of the time beyond his grasp in terms of affordability. So, he bought the next best thing — a TI SR-51A. The SR-51A was introduced in June 1975 for $224.95 which was still a lot of money for a college student at that time.
The calculator served my father well until the batteries died. Rather than replace the batteries, he opted for a cheaper fix. He replaced the batteries with capacitors, which meant that the SR-51A could only be used while plugged into an AC outlet. This wasn’t such a bad solution since the calculator only lasted a couple hours per charge anyway.
Browse these few photos and remember the calculators of yore.
Some additional information was found at Datamath Calculator Museum.