I found this guy used on shopgoodwill.com for about $20 USD a few months ago. It was on my list of calculators to procure, but the going rate of $130 USD for a new one was way out of my range. I was ecstatic to find one in such great shape for a low price!
This is an amazing calculator with some glaring issues that make it more of a mixed bag than it could have been.

This is the last calculator produced by TI with the OS that was originally designed for the TI-92, TI’s first calculator with a built-in CAS. The fact that it was written for a device with a full QWERTY keyboard is glaringly obvious. The UI has been crammed into a standard graphing calculator form factor in such a way that some key combinations can’t be silk-screened on the keypad. Base 10 log is Green Diamond + 7, for example.

The other huge problem with it is the speed reflects when it was designed. This calculator was released in 2004, and has had no upgrades since. As such, it is ungodly slow to perform a lot of calculations. In most cases, it performs on par with the Casio fx-991EX, a calculator which costs 1/7 as much. Graphing speed is pretty close to the Casio CFX-9850G from the mid 90s. This thing is unbelievably slow compared to most currently available calculators.

On the other hand, with the software being as mature as it is, it is amazing. There are program packages for the TI-89 Titanium that have no rival on any other platform. EEPro and MEPro are both freely downloadable from TI and provide a suite of activities, functions, and references customized for electrical engineering and mechanical engineering, respectively.

I’m very happy with this machine, and it does get quite a bit of use in spite of its shortcomings.

  • RocksAreCoolEnglish
    4·
    2 years ago

    The 89 was my life saver… I bought and downloaded a few apps that would do multivariable calculous, complex analyses, and partial DE. Without cheating my way through those classes, I’d had never graduated in '15. The best part? The job I got after college, I’ve never used any math higher than high school algebra.

    • JakeSparkleChickenOPMEnglish
      3·
      2 years ago

      I’ve only ever needed to use higher level math in school as well, but I am very happy that I know how to do it.

      • RocksAreCoolEnglish
        2·
        2 years ago

        I’ve forgotten all that stuff now, it’s been 8 years of not using any of it. Calc 1 & 2 along with DE were fairly straight forward for me and I was able to do so of the easy stuff in my head, but I hit my limit HARD with PDE and complex analyses. Now, I doubt I could do anything harder then find the derivate of X^n lol

        • JakeSparkleChickenOPMEnglish
          2·
          2 years ago

          I try to keep my skills sharp, but I know that there are things that I’ve forgotten over the years, too.

  • TurtleTourPartyEnglish
    4·
    2 years ago

    A TI-89 got me through my electrical and computer engineering classes in college. It was slow but essential.

    • JakeSparkleChickenOPMEnglish
      1·
      2 years ago

      I can see how it was essential! I went back to college pretty late in life, which is when I picked up my first TI, the TI-nspire CX CAS. I love that calculator and I know it well. I’ve only had the TI-89 for a couple of months but I already think that I would have been better served by it instead of the CX. It makes me realize why there is still so much praise for the TI-92 and the Voyager series.

  • AscrodEnglish
    3·
    2 years ago

    I still have mine from my college days, never used it much myself. It’s like new if you want another one, lol.

    • JakeSparkleChickenOPMEnglish
      2·
      2 years ago

      Thank you for the offer, but as understanding as my wife is, if I started getting duplicates of calculators there would be some sort of reckoning.

  • FirefoxEnglish
    3·
    2 years ago

    Interesting to hear all your thoughts on this! What’re some of the more interesting/useful software packages that are available for this thing that you can’t find elsewhere?

    I remember using a TI calculator back in high school, but I never fully understood why they were the de facto standard with standardized testing and the like with how stale their calculators have been for a while now.

    • JakeSparkleChickenOPMEnglish
      1·
      2 years ago

      I haven’t really had the calculator long enough to really explore the other software that’s out there for it, but the two that I mentioned are spectacular.

      They’re only the standard here in the US. Back in the 80s and 90s, HP marketed to engineers and professionals, TI to students. TI started dumping a lot of resources into creating educational materials for schools and offering really cheap calculators to them. Once they had established themselves as the dominant manufacturer, they decided to rest on their laurels. You don’t use TI in the US because it is innovatice, but because you grew up with it and it is comfortable.