The TI-59 is an early programmable calculator, that was manufactured by Texas Instruments from 1977. It is the successor to the TI SR-52, quadrupling the number of "program steps" of storage, and adding "ROM Program Modules". Just like the SR-52, it has a magnetic card reader for external storage. One quarter of the memory is stored on each side of one card.
A TI-59 showing a magnetic storage card being inserted into the card reader in the side.
The TI-58C
TI-59 mounted on a PC-100A thermal printer
TI-59 main circuit board
Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program. Most are Turing complete, and, as such, are theoretically general-purpose computers. However, their user interfaces and programming environments are specifically tailored to make performing small-scale numerical computations convenient, rather than general-purpose use.
A TI-59 with a magnetic storage card being inserted into the card reader on the side.
HP-41CX with magnetic card reader and thermal printer
A complete range of programmable calculators were developed in former USSR. Some of them (like this MK-52), was used even in space missions.
SwissMicros replica of the HP-15C in credit card size
