TI-57

There were three machines by this name made by TI, the first was the TI-57 with LED display released in September 1977 along the more powerful TI-58 and TI-59.

The TI-57 lacked non-volatile memory, so any programs entered were lost when the calculator was switched off or the battery ran out.

Included, with at least the original version was a book entitled "Making Tracks Into Programming".

It was self described as "A step-by-step learning guide to the power, ease and fun of using your TI Programmable 57".

Any keystroke could be stored, along with some simple program flow control commands and conditional tests.