Texas Instruments, TI-59 - Calculator - 1980-1990

The TI-59 is one of the early pocket-sized programmable calculators, produced by Texas Instruments starting in 1977. The TI-59 model is the successor to the TI SR-52, quadruples the number of program memory steps and adds ROM program modules (an insertable ROM chip capable of containing 5,000 program steps). Just like the SR-52 model, it is equipped with a magnetic card reader for external storage. A quarter of the memory is stored on each side of a card. The calculator is working; the power supply is not original but self-built, like the battery pack, as shown in the photo.