It's been some time since I used it, but I thought it would be worth sharing a quick overview of my Texas Instruments TI-66 programmable calculator. I had talked about this early in the pandemic when I used it to demonstrate how to use the SEIR model to predict infectious disease spread given an virus infectivity (R0) value. I had thought then about teaching programming concepts using keystroke programmable calculators but didn't get around to it. I hope to revisit that idea soon after completing Kenbak/Digirule and CARDIAC projects.
The TI-66 ironically is a Toshiba OEM calculator powered by two LR44/357 button cell batteries with a 4 bit CPU running at around 220 kHz, 64 numeric registers, and 512 program steps. It has a 2 line serial output for driving the TI PC-200 printer and an alphanumeric 7 segment LCD display. While it is slower than the classic TI-58C and TI-59, it does offer full instruction mnemonics instead of key locations in the program mode and has a far better battery life on two button cells to boot. This is definitely an unusual calculator, and it's quite slow, but it's also one of my favorites given its memory, programmability, and battery life. Nothing like having a programmable Turing complete computer in your pocket with years of battery life on inexpensive coin cells.
Find out more about the TI-66 here: [ Ссылка ]
TI-66 CoVID SEIR model demo: [ Ссылка ]
Some experimentation with the TI-66 serial output:
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