I went to the Pasadena City College Swap Meet yesterday, and I found this calculator.
Pictured is the Atari CC 1900 calculator. While it isn't programmable, the calculator features a memory of 32 steps. I picked this up for $5. It looks like this calculator was produced in the 1980s, but I could be wrong on that. Thankfully it runs on two AAA batteries.
This is not the only model of Atari calculators as smaller and solar versions were produced.
Some info about the Atari CC 1900 that I found.
Pasadena City College Flea Market - 1st Sunday of every month
I am looking for a manual.
Take care, Eddie