What computer language were calculators written in?

I think many of the early calculators were built with transistors functioning as logic gates, in other words, no programming language, just hardware.

At the lowest level, the instructions move data between memory and a small number of registers. Arithmetic can be performed on the registers and the result written back into memory.

Let’s say you want to get z=x + y.
What you have might look something like this:
Copy the contents of memory location 100 into register 5.
Copy the contents of memory location 120 to register 7.
Add the contents of register 5 and register 7 and put the sum into register 5.
Place the contents of register 5 into memory location 130.

Most are written in BASIC
Some are now adopting Python
Here is a well written article on programming a TI 83

Hello World

Assembly

JCL

@Dutchess_III JCL is a langue run on IBM Mainframes. Last time I checked, I couldn’t lift a mainframe.

Programming as TI83 (or TI85) is far different from the internal OS that made the calculator run.

Early TIs had Zilog CPU chips (Z80 usually) and they used a Z80-specific assembler language variant. Later TIs used a very simplified version of BASIC.

Lol! I used to work with mainframes at Boeing Computer Services @Forever_Free. Nope can’t lift them.