Texas Instruments TI-68


Brand: Texas Instruments
Model: TI-68
Type: Programmable scientific calculator
Picture: TI 68
Batteries: CR 2032
Lifetime: Introduced: 1989
Terminated: unknown
Notes: Texas Instruments calls this an "Advanced scientific calculator". It is keystroke programmable (although it lacks program flow control instructions). Has complex number functions, a polynomial root finder, alphanumeric entry, 440 memory steps dividable between program storage and user memories. Can also perform calculations in binary, octal and hexadecimal. Also available are statistical functions, temperature conversions, and a (rather clumsy) way of repeating the last command (dubbed "Last Equation Replay").

But what I find most striking is its keyboard, which lacks any kind of overview! Did anyone actually enjoy working with this calculator?
Well, yes. Some people actually did! Here’s a reader’s response:

Hi there,

I've been having some trouble with my TI-68 (display gone funny), and have been pottering about the web looking for info about potential fixes/replacements.

However, when I saw your piece on the TI-68, I felt it necessary to defend it!

I think the first thing that strikes you about the TI-68 is "wow, look at all the functions!". It's a good thing for 2 reasons, 1 - it makes you look smart to have a calculator no-one else knows how to use and 2 - no-one borrows it, because they don't know what to do with it.

I have owned my TI-68 for 9 years, and it got me past the end of school and all the way through my degree. Highlights for me include the bit functions (I haven't seen a 2's complement button on other calculators), the display having upper and lower case letters (much more readable than all caps) and the ability to store stuff in the memory, without actually looking like a programmable calculator (handy for remembering a difficult formula in an exam - the invigilators all go for the graphic calculators and ask users to clear them, but not my TI-68 - they were probably afraid of it :) ).

So to answer your question, yes I enjoy using the TI-68 very much!

If you dislike it so much, why don't you sell it to me? That would save me the trouble of trying to repair mine (have to try applying heat to the flexi connector between circuit and display - wish me luck).

In summary, apart from your unkind comments re: the TI-68, you have a very interesting site. I was interested to see the award for school calculator go to CASIO fx-82. There was a real calculator war between the CASIO fx-82C and the TI-30 at my school (I was a TI-30 user - still working on original battery (12 years!)). Ahh the memories! Keep up the good work!

Matthew Norrie

When I came across the CASIO fx-5000F (semi) programmable calculator it turns out it was possible to create an even more complex layout though.

Personal Experience

Repair: This calculator does have a poor build-quality, I've seen multiple examples of this calculator where the display does not work and has many missing pixels, like the issue Matthew Norrie has with his TI-68 described above. There must be official ways to fix this, but a small length of UTP cable also does the trick. My own specimens are still working after applying the "fix" shown here:

TI 68 fix