Keystroke programmables, left to right:
1. TI-55: My first programmable calculator (01978). The equals key is missing--it led a full life.
2. TI-55-II: LCD enhancement of the TI-55.
3. TI-57: Predates the TI-55 in time, although it's a more powerful programmable.
4. TI-58: Non-constant memory version of the TI-58C below. This, the TI-58C, and the TI-59 are ROM-cartridge programmable.
TI-58C calculator with PC-100C printer. My second programmable calculator (01981; printer 01982) and the machine that took me through one year of high school (and several lunch periods playing the Sea Battle game on circular graph paper), 4 years of college, 3 years of grad school, and the 2 years of my first teaching job--and it shows!. I finally replaced it when the second battery pack went dead for good, although the package shown here still runs off AC current.
Magnetic card programmables, left to right:
1. HP-67: One of the shining lights of the Hewlett-Packard line.
2. SR-52: Texas Instruments' first card programmable machine. This may be TI's heaviest handheld calculator.
3. TI-59: Magnetic card version of the TI-58.
TI-58C with Pool Water Analysis module: Unlike the other TI ROM modules, the Pool Water Analysis module uses a keyboard overlay rather than a card in the top slot to redefine keys for its functions. With the PWA module, a swimming pool owner could do all the calculations necessary to keep a pool's chemistry properly adjusted. Interesting input options include "Cloudy", "Green", and "Brown" [on the 4, 5, and 6 keys] to indicate water color--although my personal opinion is that if you have a pool full of brown water, you need help beyond what a TI-58C will provide...
TI-57 LCD: The functionality of the TI-57 packaged into the angled case used by TI in the early 01980's.
TI-66: A somewhat-scarce later-generation TI programmable in the horizontal format.
TI-74 BASICalc: This machine can function as a scientific calculator or be programmed in BASIC.
TI-95 ProCalc: An updated version of the TI-74 dating from 01986.