Introduced soon after HP-65, the SR-52 is the first programmable handheld calculator from TI and offers some extra features: a larger programming space, and a printer (the PC-100A, which was sold separately). You would need a large hand though, this calculator is thicker than any other TI or HP handheld calculator.
More technical details at the Datamath museum sire here.
Many TI calculators from the SR-52, TI-58 and 59 families have been badly damaged by battery corrosion. Most of them – this one included – have lost their contacts to corrosion so original BP1 battery packs but this may be considered a benefit in disguise. The loss of the battery contacts allowed me to replace the original BP1 battery with a phone battery of – roughly – double the capacity of the original one. The plus here is that this new battery is fully encapsulated in plastic therefore any leaks are much less likely to get out and damage the machine.
The calculator works normally but the card reader was not refurbished. I have removed the old goo that resulted after the original rubber wheel decayed but I did not replace it yet.