David Butleradded June 21, 2018

This is yet another member of the Majestic line of Texas Instruments calculators. This model made its debut in 1976 shortly after the SR-40. The circuitry is more complex here, with four separate chips, as opposed to single chip machines like the SR-40 and TI-55. It was meant to be a continuation of the earlier SR-51A, and is sometimes considered a hybrid of the TI-55 and SR-51A.
This calculator used the rechargeable BP6 battery pack, delivering 2.4V. Unlike the later BP7 pack, there is no circuitry in the battery pack to step up the voltage to 9V. That is handled inside the calculator. This pack was only used here and in early versions of the TI-57. It was not fun to clean the corrosion and replace the cells in this thing. However, it is now fully working. I am glad, as these dont seem as common as other Majestic line members.
Afterwards, i tried to redo the trim. Im not sure if it was more silver or gold originally, as there was very little left, and the paint can change color over time. However, i consider it an improvement.

Manufacturer

Texas Instruments Majestic Line

Model Number

SR-51-II

Year Made

1977

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