Texas Instruments
Model: SR-50
Battery: BP 1
Adapter: AC9200
Year: 1974
Chip: TMC0501 / 0521
Manual: with permission www.datamath.org
Info: TIP line - classic first GENERATION
Model: SR-50 A
Battery: BP 1 A
Adapter: AC9130
Year: 1976
Chip: TMC0501 - TMC0503
Manual: with permission www.datamath.org
Info: classic second GENERATION
Model: SR-50 Dismac
Battery: BP 1
Adapter: AC9200
Year: 1974
Chip: TMC0501 / 0521
Manual:
Info: Fellow calculator collector Marie Lisa Collas surprised us in December 2015 with this unusual looking SR-50manufactured for Dismac Industrial S.A. in Brazil. Texas Instruments changed the appearance of the original dramatically by simply switching the silver colored aluminum bezel from the display frame to the keyboard. Purchased in 2022.
Model: SR-51 1v
Display: 10 + 2
Battery: BP 1
Adapter: AC9200
Year: 1975
Chip: TMC0501, TMS0522, TMC0523
Manual:
Info: With the SR-51 Texas Instruments began a series of scientific calculators that added statistical functions and conversions to the "usual functions". But none of them are engineered as flawlessly as the SR-51. It was built as a tank to survive decades of use like its close relative SR-50. Compared to previous models, the SR-51 got a keyboard design with white, gray, yellow and orange keys and gave a perspective to later TI calculators. To reduce manufacturing costs and to give a similar look and feel to the SR-52 and SR-56 calculators, the SR-51 was replaced within months with the SR-51A. Logically it is quite rare. However, two different variants are known: this model from an early production batch uses huge yellow characters for the 2 shifted functions, while the later SR-51 sports much finer print.
This rare model had many parts corroded by battery acid, the 7-segment displays completely corroded, the replacement and cleaning of the keyboard can be seen on the side.
Model: SR-51 2v
Battery: BP 1
Adapter: AC9200
Year: 1975
Chip: TMC0501, TMS0522, TMC0523
Manual: with permission www.datamath.org
Info: